Suspension rebuild and disc brake swap...by a noob for noobs

[rich006]

I just rebuilt the front suspension on my '74 Swinger slant and replaced the drum brakes with disc. Having never done anything like that before, I thought it might be helpful to post some pictures and descriptions in case any other newbies out there want to try it. The job is mostly done now but there's a lot to post so I'll do it in installments. Here's the "before" picture.

The vision for the car is a daily driver with OEM-type components (no tubular control arms, adjustable proportioning valves, etc). I'm not trying to restore the car to its showroom state but I want all the upgrades to be factory options from '74, with a few exceptions. This car was originally outfitted with base mechanical components except for power steering.

The disc brake cars in '74 had the large (4.5") bolt pattern, but the drum cars like mine still had the small (4") bolt pattern. In order to avoid having different bolt patterns front/rear, the first step was to upgrade the stock 7 1/4" rear end to an 8 1/4" with LBP (LBP 7 1/4" axles exist but are rare). I found the 8 1/4" at my local salvage yard for $250 plus a little extra for the u-bolts and shock plates. Long story short, it needed all the bearings and seals replaced which cost me a bundle at the shop when I decided not to tackle that myself--you can read about that here. On the bright side, it turned out to be a sure-grip which was a pleasant surprise (2.71 gear ratio which is fine by me).

If I had to buy new wheels anyway I might as well go with rallyes for looks. I debated ordering some 15x7" reproduction wheels but decided to go with the factory option 14x5.5". Before making that decision I made sure I could find decent 14" tires. I went with Michelin Defenders because they have worked well on my wife's Odyssey and are available in the size I wanted--205/70R14 which is very close to the outer diameter of the 6.95/14 stock tires. (I considered steel wheels, dog dish caps and BFG T/A radials with white letters but that would have been too "muscly" for my car. I also considered keeping the original "deluxe" wheel covers but I find them ugly.) Having chosen rallyes, I got a set of 4 with trim rings and center caps (the "acorn" type that was used in '74) from a FABO user. One of the rims turned out to have the lug holes reamed out, so then I found another pair of rims from another FABO user. That left me with 5 good LBP rims, which is good because I needed a LBP spare tire anyway. I sandblasted the rims (thanks to MOPARMITCH who let me use his blaster), then painted them with rattle-can primer, silver, and clear matte wheel paint.

While replacing the rear end I also swapped in new 5-leaf stock replacement springs and bushings from ESPO Springs-n-Things (great products, great tech support). To keep the factory setup, I went with 10" drum brakes. My 8 1/4 actually came with 11" plates, so I had to go back to the salvage yard for 10" backing plates, parking brake levers and struts. I reused my old parking brake cables, wheel cylinder push rods and shoe guide plates, and I got all the other brake components cheap from RockAuto. More on the rear end swap here. One thing I found out is you can't always use torque settings from the shop manual: read here about the new wheel cylinder bolt I broke off. I also had a hard time flaring the new brake lines, which I asked about in this thread. Here's a pic right after my son and I finished installing the new springs and rear.

You can see the car's tail is higher than before. The front end is too low because I hadn't yet adjusted the front ride height, which needs to be done after replacing the rear springs. Not shown in the picture is how the new springs immediately reduced rolling in turns, even though I hadn't touched the front end yet. This was Easter Sunday 2016 (yeah, we took a morning break for the holiday). In the next installment I'll start the front end project.

 

[rich006]

Before I move on to the front end, here's the parts list for the rear end swap:

• 8 1/4" rear end with u-bolts, shock plates and drive shaft, B&B Salvage (off a '74 Valiant)
• leaf springs and bushings, ESPO
• shock absorbers RockAuto
• differential cover gasket, Pep Boys
• rubber gear case bumper, Silke's
• Gorilla "acorn" lug nuts #41187HTB, Amazon
• Gear oil, Pep Boys
• 10" backing plates, struts, and parking brake levers, B&B salvage (off a '70 Satellite)
• 10" drums, jet.com
• shoes, RockAuto
• Wheel cylinders, RockAuto
• drum brake spring kit, RockAuto (one kit covers right and left)
• self-adjusting hardware kits, RockAuto (separate kits for right and left)
• 25' of nickel-copper brake line, Amazon

That list does not include the rims and tires. Some notes on parts:

• When you go to a larger differential you'll need a shorter drive shaft. I guessed the donor car's drive shaft would be the right length because it came off a 74 Valiant 4-door which has the same 111" wheelbase as the '74 Dart. I was right but unfortunately it was bent. I ended up taking my existing driveshaft to be shortened at a driveshaft shop.
• You need new lug nuts because LBP uses 1/2" threads, but SBP uses 7/16".
• Gorilla lug nuts come in packs of 4, so you need 5 packs.
• The rubber bumper is what people sometimes call a pinion snubber.
• New rear wheel cylinders come with smaller bleeder screws with 7mm hex. If you can find some good used ones I'd recommend rebuilding them instead of replacing.

 

[rich006]

After a few days of satisfactory driving with the new rear end, I was ready to dive into the front suspension and brakes. The goal was to have the same setup you would have had on a 1974 car from the factory with disc brakes, with two exceptions. First, I went with 1976 calipers which have a larger piston than the 1973-1975 calipers. Second, I got offset upper control arm bushings to increase caster. One of my complaints had been a lack of steering feel and stability on the highway, and some research on FABO told me that (1) increasing caster could help, and (2) you'll never get enough caster with regular control arms and bushings.

First, the parts list. I considered several disc upgrade kits and almost went with The Ram Man's kit, which is essentially factory parts and includes a sleeve so you can keep pre-1973 upper control arms. In the end I decided to put together my own kit. There's a nice parts list for the 1973+ disc swap at Disk Brake Conversion Info. In my case I didn't need new upper control arms since I already had the 1973+ suspension. The hardest parts to find are the spindles, a.k.a. steering knuckles which you can only get from a donor car. I got some sparkling ones, including the wheel bearing hardware, caliper brackets and dust shields from FABO user hemi71x. Here's the whole disc swap list:

• Rotors, RockAuto
• Lower Ball Joints, RockAuto
• calipers, RockAuto/Amazon
• Spindles, dust shields, caliper brackets, axle retainer & nut, from FABO user hemi71x
• Brake pads, RockAuto
• Rubber hoses, RockAuto
• Inner and outer wheel bearings, Napa
• Inner bearing seals, Pep Boys
• Wheel bearing dust caps, RockAuto
• Proportioning valve, Dr. Diff (eBay)

It would have been cheaper to get the kit, but I could have saved some money by getting a used proportioning valve and less pristine spindles.

Next up: the front suspension parts.

 

[rich006]

While swapping in disc brakes, it made sense to replace all my 40+ year old front suspension bushings at the same time. This added a lot of work to the project but it was definitely easier to to both jobs at once than separately. For suspension parts, I considered ordering ESPO's kit, but the Moog parts are reasonably cheap and I wanted their offset upper control arm bushings. I got everything from RockAuto:

• outer and inner tie rod ends
• lower control arm bushings (2)
• offset upper control arm bushings (2 sets)
• strut rod bushings (1 set for both sides)
• rebound bumpers (2)

I didn't replace my lower control arm bumpers because they were good enough to reuse. I considered replacing the steering arms along with the tie rod ends, but decided to save the steering for later.

I learned one lesson the hard way: always check your RockAuto parts as soon as you get them. One of the bushings in the strut rod set was the wrong piece. Moog would have replaced it, but I couldn't return it because it was more than 30 days after purchase. I had to order a whole new set.

Finally, I should mention perhaps the most important part of all: the factory service manual. I referred to it extensively before and during the project.

 

[pishta]

Rockauto has some cheap parts, but I found out that most of their stuff is surplus from buyouts, discontinued parts, custom branded parts and bulk lots. So always check your order as fast as you can. I opened a box labeled Idler arm bushing and inside was a brake cylinder seal!

 

[rich006]

To position the car I set the parking brake, put the transmission in neutral (to unlock the steering), chocked the rear wheels, jacked up the front end by the K-member, and placed jack stands under both frame rails. I left the floor jack under the K-member and kept some weight on it, but most of the weight was on the stands. This was because somewhere I read that lifting the K-member can help ease out the torsion bars.

I decided to do one side of the car at a time so I would have the other side for reference. I did the left side first, but I didn't take many photos until I got to the right side. First things first: PB Blaster on every fastener.

To start the tear-down, I disconnected the brake line, leaving the rubber hose attached to backing plate.

The hinged line wrench is really helpful. The rusty clip right above the painted tab pulls out with pliers and taps back in with a hammer later.

Next I needed to disconnect the outer tie rod end from the lower ball joint. Not having a pickle fork, I did it by removing the Cotter pin and castle nut, threading the nut on upside down until its surface was flush with the end of the threads, and hammering downward on the nut and threads. I used this technique several times, and a few times the nut got jammed onto the threads so that turning the nut caused the whole joint to turn instead of unthreading the nut. In those cases I hammered the joint back in to hold it so I could turn the nut, then it only took a light hammer tap to punch the joint out again. A pickle fork would have made the job easier, especially if you're not trying to save the rubber boot. A couple of times I tried hammering from the side as some people suggest, but I never got that to work, perhaps because I wasn't using a big enough hammer.

With the tie rod separated from the lower ball joint, I then removed the LCA, UCA, strut rod, spindle, lower ball joint, and brakes as a unit, as follows. I removed the Cotter pin and nut from the forward end of the strut rod (right under the radiator), the nut from the forward end of the LCA pivot (those are both 15/16" nuts), and pulled the retainer ring from the aft end of torsion bar. Here's a pic of my wrench on the right-side LCA pivot nut. This is looking upward. My finger is pointing at the strut rod.

And here's the torsion bar retainer ring.

Next I backed out the torsion bar adjuster bolt to remove all tension from the bar. Here's a shot from beneath, looking up at the lower control arm.

Notice my gloves? Those are cheap rubberized gardening gloves. They worked really well for this job.

With the retainer ring out, only friction keeps the t-bar from moving aft. However, there can still be a lot of friction. To knock it loose, I put a one-foot length of 2x4 in front of the LCA and hammered it aft.

My son the photographer took a few bumper-reflection selfies while I worked.

Once the torsion bar was loose, I pulled it aft until it was hanging by the middle. On the left side bar, the boot was damaged slightly when I pulled it off the bar, so on the right side I just left the bar on the car. Here's what it looked like from the side:

and from the front:

Once the t-bar was out of the LCA, I removed the UCA cam bolts and knocked the UCA loose from its mount (this took a few hammer blows).

I detached the shock absorber from LCA, removed a little plastic shield to allow the strut rod to come aft with its bushings still on, and then just yanked the entire assembly aft until the LCA pivot and strut rod came loose. At this point the control arms, spindle, strut rod, and brakes were separated from the car. All that stuff together is pretty heavy.

With the whole assembly on the ground, I separated the upper ball joint from the spindle using the same technique I used on the tie rod end, and did the same again to separate the lower ball joint from the lower control arm. I left the upper ball joint in the upper control arm because I wasn't going to replace it (the upper ball joints were replaced less than 2000 miles ago). After I separated the strut rod from the lower control arm (one more nut on the rear of the strut rod), both control arms were free and I discarded the spindles, brakes and lower ball joints.

At this point I noticed my lower control arms did not have the tabs where the sway bar end link attaches. Apparently Ma Mopar only welded the tabs on if the car was to have the sway bar. I'm not adding a sway bar now, but I'd like to have the option later and so it made sense to add the tabs now. Several companies sell aftermarket bars, but since I'm trying to keep factory equipment, I wanted tabs that would fit the factory 1973+ bar. Hotchkis sells a factory-type bar along that comes with tabs to be welded on, similar though not identical to the factory tabs. They sold me just the tabs for a reasonable price.

Next: freshening up the lower control arms.

 

[rich006]

With the control arms removed, the next step was to press out the old bushings. I used a loaner kit from Advance Auto:

This kit had most of the cups and things I needed, and the silver C part fit nicely in my small workbench vise. Pressing out the LCA bushings is a three-step process: (1) press the pivot shaft out of the pivot, so that the shaft takes the inner bushing sleeve with it; (2) remove the rubber and outer sleeve of the bushing from the arm; and (3) remove the inner sleeve from the pivot shaft. There are a lot of different ideas how to do the last two steps. I used the loaner kit to press the pivot shaft out. That part was relatively easy. I yanked the rubber out with pliers and screwdriver, which left only the outer sleeve in the control arm. I used a cold chisel to score a line down the inside of the outer sleeve, then hammered a screwdriver down between the outer sleeve and the control arm until there was enough of a gap in there to get pliers in. After that the outer sleeve pretty much fell out. That whole process took about 45 minutes the first time, and about 20 minutes the second time. I'm sure it would have been easier to get one of the specialty tools for the job, such as this one. I made a few little nicks in the control arm, but nothing that would prevent pressing in a new bushing. To get the inner sleeve off the pivot shaft, I first tried using a cold chisel as described here, but I didn't have a good way to hold the shaft in place while chiseling. I gave up and took it to the machinist at my work place, who cut through it with a mill:

On one of them he cut a little too deep and went into the shaft a little bit:

But not so much that a new bushing wouldn't be snug on it.

With the LCA bushing out, I turned to the upper control arm bushings. Those came out using the loaner kit. It took just about all the muscle I could muster, but it sure felt good popping out. The rear bushing had a steel sleeve (about 3/8" wide) around it, that looked like part of the control arm until it fell off when the bushing came out. At first I thought I had broken something, but some research on FABO convinced me those rings aren't necessary.

Now the UCA was ready to wire brush, paint, and press in new bushings, but I still had some work to do on the lower arm. I noticed that the pivot was loose in the arm, as you can see in the video I posted here. Farther down in that thread is a nice video illustrating how to fix that problem. Instead of buying the stiffening plate, I just asked my machinist to cut plates for me. Then, since I was going to be welding anyway, I decided to weld on sway bar tabs in case I decide to add a sway bar later. I wanted tabs that would fit a factory sway bar, and the ones from Hotchkis seemed like the best bet. I'm new at welding, but with some guidance from the guys in the machine shop I was able to add the tab and the plate:

On the first one I didn't leave enough room for the 3/4" socket that is required to turn the ride height adjusting bolt, so I used a grinder to enlarge the cutout in the stiffening plate after it was welded on. I also didn't put the sway bar tab quite as high as I wanted. The picture shows the second one, which has the tab about as high up as it can be. Also, you can see the metal is pretty clean. That's because the machine shop has a sandblaster too.

Another lesson learned: if you're welding sway bar tabs and stiffening plates onto your lower control arm, do the sway bar tabs first unless you can do them without overheating the arm. When I welded the stiffening plate on, the pivot was rotating easily between the two halves of the arm, but after I welded on the sway bar tab, the pivot was tighter than I wanted. I assume the heat from welding affected the fit of the pivot arm. Probably if I were a better welder I could have done the job with less heat.

Once the welding was done, I primed and painted the control arms with Rustoleum Professional in matte black.

I had left the upper ball joint in because it was pretty new and I didn't have the socket to replace it. When painting, I just taped over it.

Next step: pressing in the new bushings.

 

[MrJLR]

Enjoying the write up!
I just did this a couple months ago. ....fun stuff!

Jeff

 

[rich006]

To press a new bushing into the lower control arm, you first press the new bushing onto the pivot shaft, and then press the shaft and bushing into the pivot. Here's the new bushing going on to the shaft:

To press the bushing and shaft into the pivot, you have to apply pressure to the bushing outer shell, because pressing on the shaft will simply push the bushing inner sleeve out of the rubber. Here's how I pressed the shaft and bushing into the pivot:

For the upper arms, a 1 1/4" socket (which I had bought for the pinion nut on the new rear differential) fit perfectly on the flange of the new bushing.

I used Moog's offset bushings oriented to provide maximum caster, meaning the outer end of the control arm is as far aft as possible--so I wanted the front of the arm offset outboard and the rear of the arm offset inboard. The directions that come with the offset bushings assume you want to increase camber (both bushings offset outboard), so if you're going for positive caster you have to ignore the directions. I didn't take a picture of how I oriented the bushings in the arm, but there is a thread or two on FABO discussing how to install them for max caster. Generally you just need to think carefully about what you have to do to move the outer end of the arm aft.

As mentioned earlier, I didn't bother replacing the ring that was on the old rear UCA bushing.

The caps for the new bushings pressed on pretty easily in a vise:

From this angle you can almost see how the cap is offset from the bushing centerline.

Next up: taking a break to cook some Hawaiian kalua pig.

 

[rich006]

While I was working on this project, my wife (a saint) was prepping for a party we were hosting for people I work with. One of the few things she asked me to do is cook the kalua pig. My family picked up a taste for this stuff when I was stationed at Kaneohe Bay. It's traditionally a whole pig cooked in a charcoal pit covered with leaves and dirt for many hours, but you get almost the same effect very easily at home with a pork shoulder cooked in a crock pot with liquid smoke. Here's everything you need:

Pork shoulder, a.k.a. "butt" is the meat you want. Bone-in might give a little more flavor but honestly I don't notice a difference. You want about 5-6 pounds. I was actually doing a double recipe here in two crockpots.

Rinse the meat and pat dry, put it in the crockpot, then poke it all over with a fork to allow the salt and smoke flavor in.

Next add the liquid smoke and the salt. Some brands of liquid smoke have other stuff added, but the good stuff is just water and burned hickory. Dribble one tablespoon (yes, a whole tablespoon) of this all over the top of the meat:

and sprinkle a tablespoon or two of salt:

How much salt to add is a matter of taste but it also depends on what kind of salt you use. If you can find the pink Hawaiian salt (maybe at Whole Foods), 2 tablespoons is about right; it's not as salty as other salt because it contains other minerals like iron. For the kind in the picture, 2 tablespoons was a bit much.

Now just turn the crockpot on low and leave it alone for up to 10-16 hours. The flavor keeps growing the longer you cook it, but too long and the meat starts to get mushy. I started mine about 11pm and my wife turned it off at 3pm the next day, shortly before the party started. Note: this stuff will really make the room smell like smoke, so I like to cook it on the screened-in porch.

Once it's done cooking, just shred the meat with a couple of forks and dig in. In Hawaii it's served with white rice (rinsed, soaked Calrose gives you that Asian-style rice they like in Hawaii) and macaroni salad, but it's also good with barbecue sauce and rolls.

 

[H22A4]

Great write-up so far! Thanks for taking the time to document it so others can learn. Including the dinner menu is a nice touch.... cars and meat is a great combo.

 

[rich006]

Time to put the suspension back together, this time with disc brakes.

Looking at the steering crossbar, next to where the inner tie rod goes, I noticed the steering idler arm was missing its grease fitting.

The fitting should be on the top. I removed a grease fitting from one of my old tie rod ends and tried to screw it into in the idler arm, but the hole was too big. I decided to put that on my list of things for the alignment shop to take care of, but it turned out they weren't able to find a fitting that would thread in either. I suppose it got knocked loose and stripped the threads as it came out. I'll need to replace the steering arms (Pitman and idler) at some point, which may be soon because I have a power steering fluid leak from the gearbox anyway. If I have to remove the gearbox that would be a good time to replace those arms. In the mean time I'll just drive it without the grease fitting. There doesn't seem to be any play in the joint, so it should be OK until I get around to fixing the gear box leak.

Here's the tie rod with the new inner and outer ends and the grease fittings installed (7mm box wrench). I cleaned it up with a lot of WD-40, a wire brush and a screwdriver. Then I worked the new ends in and out a few times until the threads were smooth enough to turn by hand. You don't want the alignment shop to have to grab it with vice-grips and scar it all up. At first I was careful to make it the same end-to-end length as before, but once the wheels were installed I just eyeballed the adjustments by looking at the tires. That was good enough to drive to the alignment shop.

The inner end (left-hand threads) goes into the steering crossbar from above:

The outer end was dangling free at this point, and I was ready to install the lower control arm and strut rod.

If you put the LCA in before the strut rod you can't get the strut rod in (ask me how I know). Before mounting the LCA I attached the strut rod to the outer end of the LCA (finger tight until the suspension is at ride height). The LCA rubber bumper is also a lot easier to install before mounting the LCA, though it could be done after. Finally, you need the aft parts of the strut rod bushings on before you push the strut rod through the frame. The Moog metal bushing pieces are clearly marked as to which way they go, but all the concave sides face aft. (I could say rearward but I've been in the Navy too long for that.) The rubber pieces each have a small flange that butts up to the frame, and I put those flanges facing each other.

At this point I reinstalled the torsion bars. I greased both ends as instructed in the shop manual and made sure the dust boot was on the bar facing the right way (cup aft), then slid the bar forward into the LCA pivot. It went in pretty easily by just jiggling the LCA up and down to line up the hex. Here's where I made a potentially serious mistake:

Notice how high the adjusting blade sticks up. There's no way the adjusting bolt will reach up there. Fortunately I realized my mistake before anything bad happened.

This shows the adjusting blade in the right place. Notice the angle is either correct or it's 60 degrees off, so you don't have to be precise to get it right. In this picture you can see the torsion bar is not all the way in yet.

Don't forget to reinstall the retainer ring on the aft end of the t-bar.

There's a good amount of room for fore/aft movement of the bar, but I slid it all the way forward. The manual says to completely fill the annular openings around the bar with grease before pushing the dust boot back on. I chose to wait until after I had the rest of the suspension together in case I had to remove the t-bar again, but I never needed to.

Before moving on the upper arm, I installed the forward end of the strut rod bushing, and the pivot shaft nut, both finger tight until the suspension is at ride height (tightening them too early will ruin the rubber when you set the car down).

Next: the upper arms and spindles.

 

[rich006]

I'm not a good story teller. I tend to leave out important things, so if anyone is confused reading this, just ask.

 

[MrJLR]

I'm not a good story teller. I tend to leave out important things, so if anyone is confused reading this, just ask.

I'm enjoying it!

Jeff

 

[rich006]

When I installed the upper control arms, I set them for max caster. It turned out later that to get the camber right, a lot of that caster had to be taken out, but here's how I set them to maximize the caster on the passenger side. I wanted the rear cam bolt as far inboard as possible:

and the front cam bolt as far outboard as possible.

The cam bolt adjustments work in combination with the offset bushing orientation. As with the lower control arm pivot shaft and the strut rod nuts, I left these nuts finger tight until the suspension was at ride height. Actually I had to use a wrench to get them "finger tight"--the point is not to torque them down yet.

Next I mounted the new (disc) lower ball joints onto the new disc spindles. I decided not to paint the spindles. Instead I just coated them with WD-40 for some protection. The torque setting for the nuts that hold the ball joint to the spindle is 160 ft-lbs, which I found easier to get after the spindle is on the car. The new ball joint came with the rubber boot not installed. I had a hard time stretching it over the lip, but one of the tubes from the bushing press kit was the perfect size. I think I used a vice to press it down. Read the directions on this one--there's a vent in that boot that needs to face inboard to avoid oozing grease onto the brakes.

Also, when you screw in the zerk fitting you want it accessible from the inboard side.

With the lower ball joint installed, the spindle was ready to attach to the control arms via the upper and lower ball joints. Unfortunately my hammer technique for removing the old spindle from the upper ball joint had scarred the castle nut threads enough that I couldn't get the nut to go back on without spinning the ball joint itself. I thought it would be easy to find a new castle nut at Fastenal but they didn't have one. Napa didn't either unless I wanted to buy a whole new ball joint. I have a thing about not buying stuff I'm not going to use, so I decided to fix the castle nut. This was a Thursday. I took the nut in to my machine shop on Friday but the machinist was off that day. At that point I was at a work stoppage for the weekend, so I took the time to catch up on the honey-do list. Monday the machinist was off again. Not wanting to lose another day, I hunted around for about a half hour until I found the right size tap to clean up the threads. It's not the best organized shop, but it's probably not the worst. It was actually pretty rewarding to fix it myself.

With the castle nut fixed, I was able to mount the spindle on both ball joints, using torque setting of 100 ft-lbs given in the ball joint packaging (the Moog torque settings mostly agreed with the shop manual, maybe 5 ft-lbs more for some components). I read somewhere that when you are lining the castle nut up with the Cotter pin hole, you want to keep tightening rather than back the nut off, so I did that.

You might wonder why the bearings and inner bearing seal are on the spindle. The spindles came that way from hemi71x. He helpfully put all the old components on the spindle in the correct order, and I left them that way until I was ready to install new ones.
With the spindle installed, I could connect the outer tie rod end, which goes up through the ball joint arm. Inner and outer tie rod ends both get 40 ft-lbs.

Also in this picture you can see the setup I used to torque down the bolts attaching the spindle to the ball joint. The crescent wrench was on the nut, with the wood block keeping the crescent wrench from turning. The other wood block kept the whole spindle and control arm assembly from dropping down. I think I used my foot to push the torque wrench. During this project I really came to appreciate the click of the torque wrench: the sound of sweet relief.

Moving right along, I installed the caliper brackets and the dust shield.

[Edit: this post originally mentioned breaking off a bolt. That was actually later; see below.]

Next up: calipers, pads, etc, not to mention master cylinder and proportioning valve.

 

[rich006]

Before putting the suspension all back together I replaced the master cylinder. The most obvious difference in the disc/drum MC is that the disc reservoir is larger because disc brakes require more fluid flow than drum brakes. Less obvious is that the MC ports for drum brakes have a residual pressure valve, but the disc ports do not. (Some say later drum brakes don't have them either, but they were there in 1974. Then there's a question about whether modern replacement wheel cylinders require the ports to be there, because they may have mechanisms in the cylinders that make the residual valves unnecessary. To be on the safe side, I chose to use all factory replacement parts.)

My new master cylinder came with a new rubber ring for the push rod (to keep it from rattling?). The existing rubber was brittle, so I cut it off and installed the new one. I bench bled the new M/C according to the included directions and mounted it on the firewall. Since the brake lines were still disconnected at the wheels, I left the plastic plugs in the M/C output ports to prevent fluid draining out. That same day, I applied PB blaster to the line nuts on the old distribution block (directly below the M/C, mounted onto the frame).

Next day I removed the old distribution block and installed the new proportioning valve. (The proportioning valve is necessary with disc/drum brakes because with equal line pressure the drums would grab more than the discs. The valve reduces the pressure to the rear lines, which balances out the braking force. You can partly achieve that by using smaller rear wheel cylinders, but the proportioning valve is more sophisticated because it provides full rear pressure sometimes and reduced pressure only when necessary. The drum/drum distribution block always sends equal pressure to front and rear.) Because the input lines were already disconnected from the M/C, it was easiest to leave the input lines in the old block until after it was out of the car, so the lines came out with the block. Before installing the new proportioning valve, I went ahead and connected the input lines to it. Because the new valve's ports are not exactly in the same places as the old ones, I had to bend the lines a little by hand to make them reach from the new valve to the M/C, and I had to slightly bend the other existing lines as well. My lines were in very good condition, but if they had been rusty at all I would have replaced them all with NiCopp or prebent lines.

When I connected the pressure warning switch to the new valve, the pigtail was loose, so I squeezed it with pliers until it fit snugly.

I didn't realize it until later, but my new proportioning valve had a leak, as described in this thread. If I do this again, I'll put the valve in a vice and really crank down on the hex before installing the valve.

 

[rich006]

With the disc-brake spindles already on the car, the rest of the disc brake system was quite easy. My "new" spindles came with their old wheel bearings, but I decided to replace them with new ones from Napa. I figured the importance/price ratio for wheel bearings is pretty high. Following the directions in the shop manual, I packed the rotor cavity and inner bearing with grease (I used the red, stringy high-temp stuff), then I tapped in the inner seal using a PVC pipe connector. I packed the outer bearing, lightly greased the spindle, and mounted the rotor followed by the outer bearing, washer, and nut. I tightened the nut, then backed it off just enough to install the castle piece and cotter pin. I lightly greased the inside of the wheel dust cap and tapped it in with a hammer, 2x4, and screwdriver.

Before installing the calipers, I put the rubber-band things on the bracket grooves. On one bracket the rubber wouldn't stay in place because its groove was too worn, but even when it slipped off the bracket edge it didn't completely fall off. I guess the purpose of the rubber is to prevent the pads and calipers from rattling. The inner pad goes onto the bracket before the caliper, but the outer pad is placed in the caliper before the caliper goes on. Following the shop manual, I hammered the flanges of the outer pad to make the pad press fit onto the caliper:

I slid the caliper onto the bracket (over the inner pad) and attached it to the bracket via the clip and anti-rattle spring.

One one side of the car I overtorqued one of the bolts and broke off the head.

Bummer. I went to Sears, bought a kit to drill out bolts, and started drilling the pilot hole for the removing tool. I didn't get the kit with special bits for drilling pilot holes, so I used my 5/32" regular bit, which gave its life in the process. I guess the bolt metal was just as hard as the bit metal. Anyway, as I was drilling the pilot hole, the bolt shaft started turning with it, and I was able to back out the shaft just by reversing the drill, without even using the tool I had bought. He was a good bit; may he rest in peace.

Actually I put him back with his friends. I think he can still be of service.

Here's how the clip and spring go on:

To connect the rubber brake hose to the caliper, I had to get 7/16" banjo bolts from Napa because they didn't come with the calipers or hoses (see '73-up brake hoses, caliper bolts?). Here's the banjo bolt.

With the banjo bolt installed, I connected the hose to the hard line and clipped the connector to the frame. When both left and right sides were done, I connected the master cylinder lines and topped up the brake fluid. I tried gravity bleeding one caliper but nothing came out. Anyway, here's a shot of my beautiful new disc brakes:

Next up: setting the old girl back on her feet.

 

[MrJLR]

 

[rich006]

Before setting the car down, I made sure all the nuts that should be tight were torqued according to the shop manual. For nuts that need to be tightened at ride height I made sure they were "finger" tight. That includes the upper control arm cam bolts, lower control arm pivot shaft, strut rod at both ends, and shock absorber mounts. I also set the ride height adjusters back to approximately their old settings. With all that done, I put the wheels on and lowered the car onto the floor.

As I was lowering the car, I kept an eye on the rubber brake hoses to make sure they weren't kinked or twisted awkwardly.

Lookin' good, if I do say so myself.

Following the shop manual procedure, I adjusted the ride height. First, you measure from the floor to the lowest part of the blade that is pushed by the adjusting bolt.

Then you measure from the floor to the lowest part of the steering knuckle arm.

The difference should be 1 7/8". The height needed to be adjusted up 1" on passenger side and 1.25" on driver side. 16 quarter turns (passenger) and 20 quarter turns (driver) got it adjusted perfectly on both sides. (Later on I decided both sides were too high, so I adjusted them down a bit until the stance looked right.)

For the final tightening of the suspension nuts, I needed the suspension at ride height but I wanted the wheel off for easier access. This was tricky without a lift. First, with the car on the floor I noted the distance from the LCA bumper to the frame rail (approximately 1/2"). I jacked up the car at the K-member, removed the wheel on one side, set a jack stand under that side's frame rail, and set another jack stand under the rotor. Then I lowered the car carefully onto both jack stands. If the LCA bumper was not about 1/2" from the frame rail, I adjusted the jack stands and tried again.

With the suspension set at ride height, I tightened the UCA cam nuts, LCA pivot shaft nut, strut rod nut at the LCA (on one side I couldn't get enough leverage to get that one all the way to 105 ft-lbs), the strut rod-to-frame nut (which I had to torque by "feel" because I didn't have a long enough socket to use a torque wrench), and the shock absorber bottom and top. On the top end of the shock, I didn't use the torque setting, but tightened it just to where the rubber part of the bushing squished out to the edge of the metal part. (I think the new shocks have different bushings than the original factory ones.) Then I reinstalled the wheel and set the car back down.

When both sides were done, I eyeballed the alignment: camber, caster, and toe-in.

• Camber: with the offset UCA bushings I had noticeable negative camber, so I adjusted the aft ends of both UCA's outboard until I couldn't see the negative camber by eye.
• Caster: I didn't worry about trying to set caster. Basically, I wanted as much as I could get, and I had previously set it as high as it could be. Raising the camber inevitably lowered the caster.
• Toe-in: I adjusted toe-in as close to zero as I could by eye, by adjusting the tie rod lengths. I tried to make equal adjustments on both sides so the steering wheel would be nearly centered.

The next step was taking the car to my local tire shop for an alignment. But first, here's a picture of the unsung heroes of my project. I truly couldn't have done it without my trusty jack stands.

Thanks for keeping me safe, guys!

 

[rich006]

The last step was the alignment. But before I could drive to the shop I had to bleed the brakes. Conveniently, the disc brake bleeder screw is much more accessible than the bleeder on the front drum brakes.

I have a national-brand tire shop nearby whose manager really likes old cars. He's mounted several tires for me and never let me pay, so I thought I owed it to him to let him do the alignment. On the whole that was a pretty disappointing experience. I gave him the specs I wanted: caster +3 degrees, camber -0.25 degrees, toe-in 1/8-1/16" (loosely based on Ehrenberg's "skosh" specs you can find many places on the web) and he agreed to do it. Next thing I know, I'm getting a call from the shop because they want to know how I want them to set the ride height. At least they asked... Anyway, the alignment guy had adjusted my ride height based on measuring from the floor to the fender lip. I went in to show him how to do it right, but he didn't have anything straight to lay across the lift, so I just told him to set the alignment at the ride height as it was. Here's the best he could do with his fancy computerized machine:

The caster (two top measurements) is close to my desired +3.0 degrees. The camber (next two) shows -0.50 as the target because the computer wouldn't let him dial in -0.25 degrees camber. The actual camber is -0.04 and -0.32, not too far off. The bottom two measurements are the toe-in. The machine requires toe-in to be measured as an angle, and he didn't know how to convert, so he just set it to zero. Before he finished, he assured me the steering wheel would be centered, but while driving home I noticed that it wasn't really that close at all.

After this experience I was tempted to do my own alignment as described in this awesome post. However, that would take a long time and I'm not doing any high-performance driving. For me, a better solution would be to shop around more carefully for an alignment shop that does good work on these older cars.

 

[rich006]

The alignment was a couple of weeks ago and I've been driving the car almost daily since then. There's still a little softness in the brake pedal, indicating some air in the lines. However, I'm waiting to re-bleed the system because I still need to replace my seeping proportioning valve (see my other thread on that).

As for driving quality, I've noticed a big improvement. For one thing, I no longer hear bushings squeak when I go over bumps. Even better, the car sways a LOT less in turns. Even without a sway bar it corners more or less like a new car. Not a sports car, mind you, but a typical modern car. I had already noticed an improvement after installing the new rear leaf springs but before rebuilding the front suspension. I'd say about half of the reduction in sway is due to the leaf springs, and the other half is due to the new bushings up front. Now even with the bench seat I don't feel like I'm sliding off every time I go around a corner.

In addition to the reduced roll, I notice the car feels much more connected to the road, especially going over rough areas at higher speeds. Part of that improvement must be due to the Michelin tires, which are far better than the cheapo white-stripe tires they replaced. But I think part of it also is the new bushings, and part is the positive caster. Overall the driving is a lot more predictable, which means safer and more enjoyable.

The braking action may be a little different with discs compared to drums, but the difference is not that radical. I can definitively say that new discs are better than old gouged-up drums, but I couldn't say how new discs would compare to new drums.

Last but not least, my stance is vastly improved, mostly due to the new rear leaf springs. Also, switching to large bolt pattern gave me an excuse to change wheel style. I think the rallye wheels compliment my car's trim better than the old "deluxe" wheel covers (even though I didn't install my trim rings--I posted about that over here).

On the whole I'm extremely pleased with my new suspension. I love driving my "new" car, and I have a great sense of accomplishment now that I really understand how the suspension works. Thanks to FABO for providing much of the information, parts and help I needed for this project. See you on the road!

 

[scott657]

subscribed, I will be doing all of this soon

 

[rich006]

To anyone who might have found this thread useful, unfortunately Dropbox has stopped allowing image sharing. Even if I wanted to go back and redo all the links, it seems the posts are too old to edit. If you'd like to see the photos, start a "conversation" including your email address and I'll share a Google Drive folder of the images with you. (I don't know any way to share Google files other than by using your email address.)

 

[Dfr360cuda]

 

[rich006]

By popular demand, here's a link that I hope will let everyone see the photos from the posts above. Each post within this thread has its own folder. Start a conversation with me if you have trouble with the link. You may need a Google account to view the images.
1974 Dart front end rebuild - Google Drive