Front Suspension Rebuild Issues

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Gandy Dancer

Gandy Dancer

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Hello FABO - I recently put front disc brakes on my 66 Barracuda. In the process, I replaced the front strut rod bushings(new), idler arm (new), lower and upper control arms(used), tie rod ends(new). It is a mixture of new and used parts. Prior to the replacement the car was drivable, but when I hit a bump it move across the road. Now that I've replaced it, the car is barely drivable! The left side tie rod is screwed all the way out, and the right side is screwed all the way in. I took it to a mechanic and he says that the angle on the steering parts is to high, and that they need to be lowered. I can't quite figure out how to get this front end together. Any recommendations would be appreciated. These are preliminary pics. I will snap some more.
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Very first thing is go to MyMopar and download a or more than "a" service manual. You may have to settle for Dodge vs Plymouth etc

Then go to this All-Par article and refer to the "skosh chart" ESPECIALLY if you are using radial tires. "The book" specs are for bias ply tires

Turn of the screw: front end alignment for performance...

Be sure to "jounce" the suspension so that it "settles" otherwise the adjustments will not be "true." It is wise to align it, drive it, and recheck settings

The order of alignment, after getting things assembled is

1...Ride height set by the bolts on the underside of the lower arms. Even if you don't want it "stock" you want to look at the bump stops and set height so you have some movement of the suspension between upper and lower bump stops

2....Then you set camber/ caster and you set them together. It is sometimes difficult to get the readings you want as adjustment is limited ESPECIALLY IF YOU did not install the upper offset bushings AND ESPECIALLY if you have power steering which "wants" more caster

The caster you want is "generally" with the upper arm ball joint pointed to the rear. This means you must move the adjuster in the front to move that end of the arm OUT AWAY from the car, and move the rear adjuster so that end of the arm moves IN TOWARDS the car. This tilts the spindle to the rear, for max cast.

HOWEVER that adjustment affects CAMBER. So you must now "give up" a little bit of caster to get the camber you want

3...Last you set the toe. Pay attention to "if" the steering box is centered. The way you do that is "rough" it into toe, and 'walk' the tie rod adjusters on both sides so that the steering wheel is centered while keeping the toe adjusted. This might take "a try or two." Set the toe, go drive it, and see if the wheel stays centered. You may have to "fudge" some on "centered" because on flat vs crowned roads, that migiht change
 
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You have way to much negative caster, not sure why but move your rear cam all the way in and the front cam all the way out and see what happens. You want the upper ball joint farther back than the lower ball joint, your upper ball joint is way forward of the lower ball joint. This will also lower your steering arms when you get more positive caster.
 
I agree on the responses posted so far. I think 67Dart's article is useful for alignment specs, but I think you also really need a shop manual to learn how to properly assemble and dis-assemble your front suspension.

I'd add that if one tie rod is lengthened as much as possible while the other is shortened as much as possible (which is how I read what you said), then I'd think your steering box isn't centered. It has to be centered before you adjust the tie rods, and they should be more or less equal length on both sides.

Ride height is adjusted by turning the screws (will take a 3/4 inch socket) coming out on the inside middle of the bottom of the lower control arms. The pivot shaft should be loose in the K frame while you are doing this (i.e., the front nut not fully torqued down). The manual gives specs for the proper ride height. And if you didn't check the condition of the lower control arm bushings before installing them, you should have. If they are worn, your car will never handle very well. Just know that replacing the lower bushings is a booger of a job. If you don't have a shop press, you'll need to farm that job out.

Here's an A body lower control arm with a new bushing installed. Note the rubber around the base of the pivot shaft - fully intact as it should be, not rotten with pieces missing.

20171004_171509.jpg
 
^^And I forgot to add^^ keep in mind as you do all this that something you missed might be bent/ broken/ damaged, and skewing your thought process. Also check that the steering box mounting bolts are TIGHT
 
Gandy Dancer said:
, I replaced the front strut rod bushings(new), idler arm (new), lower and upper control arms(used), tie rod ends(new)
Click to expand...
Are you sure all the new and used parts are correct for the year of car the discs came from?

To get the tierod ends correct. Each should be turned in an equal amount, if the left is 5 turns in, the right should be the same.
 
These are all great points from everyone. I will go through all of the recommendations everyone has given and hopefully I will get to a better point. I researched all of the parts that were purchased for the car, and they all were correct. I'll need to try and ensure the steering box is centered, before I start making the adjustments.
 
Gandy Dancer said:
These are all great points from everyone. I will go through all of the recommendations everyone has given and hopefully I will get to a better point. I researched all of the parts that were purchased for the car, and they all were correct. I'll need to try and ensure the steering box is centered, before I start making the adjustments.
Click to expand...
..........and on that note.........assuming the parts for the wheel/ column/ coupler are as they should be, and are not modified, IE someone has not filed out the master spline, there is "some" possibility that the wheel will end up upside down when the box is centered. If you did not change anything and it was OK previously, then don't worry. What can happen is, if you take the flex coupler apart and accidently get it slid back together 1/2 turn "off" then the steering wheel will be wrong side up at center
 
Something I didn't see in the responses was the reason that the car changes lanes when you hit a bump. Ready for it .............................a very common problem made much, much worse because your tie rods are now adjusted to different lengths on each side.. BUMP steer. When the suspension rises and falls , the tire/wheel assembly follows and arc. Iff the tie rod is effectively longer on one side and shorter on the other the front tires will follow different arcs. This is the same as turning the steering wheel to one side or another.
Refer to the FSM for basic dimensions and proper assembly procedures on doing front end/suspension repair.
Here is a link that explains this situation:
Bump Steer Explained - What Is It and How It Works - Hot Rod
 
Hello everyone - I had a little time over the weekend to adjust the caster. I moved the upper control arm out in the front, and moved the rear in as far as possible on both sides. I then centered the steering wheel, by strapping it to the brake pedal so that it would not move, and stay centered. I then proceeded to adjust the tie rods. I'm happy to say that the tie rod adjustments are far more closer to even on both sides now than they ever have been before. I tested it out and was able to drive relatively straight down the road. I will need to continue to more tweaking to it, because my steering wheel is about 10-15 degrees off to the lower left, in the 40 degree position. I'll need to research the torque settings for the upper control arm bolts. I'll also research a set of tubular UCAs. I think a good test will be to cruise it tomorrow over to Dunkin Doughnuts in Bowie Maryland. Thanks for all the help, and I will continue to update everyone on the progress!!!
 
Glad it worked out for you, now maybe hit the alignment shop.
 
67Dart273 said:
Very first thing is go to MyMopar and download a or more than "a" service manual. You may have to settle for Dodge vs Plymouth etc

Then go to this All-Par article and refer to the "skosh chart" ESPECIALLY if you are using radial tires. "The book" specs are for bias ply tires

Turn of the screw: front end alignment for performance...

Be sure to "jounce" the suspension so that it "settles" otherwise the adjustments will not be "true." It is wise to align it, drive it, and recheck settings

The order of alignment, after getting things assembled is

1...Ride height set by the bolts on the underside of the lower arms. Even if you don't want it "stock" you want to look at the bump stops and set height so you have some movement of the suspension between upper and lower bump stops

2....Then you set camber/ caster and you set them together. It is sometimes difficult to get the readings you want as adjustment is limited ESPECIALLY IF YOU did not install the upper offset bushings AND ESPECIALLY if you have power steering which "wants" more caster

The caster you want is "generally" with the upper arm ball joint pointed to the rear. This means you must move the adjuster in the front to move that end of the arm OUT AWAY from the car, and move the rear adjuster so that end of the arm moves IN TOWARDS the car. This tilts the spindle to the rear, for max cast.

HOWEVER that adjustment affects CAMBER. So you must now "give up" a little bit of caster to get the camber you want

3...Last you set the toe. Pay attention to "if" the steering box is centered. The way you do that is "rough" it into toe, and 'walk' the tie rod adjusters on both sides so that the steering wheel is centered while keeping the toe adjusted. This might take "a try or two." Set the toe, go drive it, and see if the wheel stays centered. You may have to "fudge" some on "centered" because on flat vs crowned roads, that might
change
Click to expand...
Dell I think you answered my question on my QA suspension.
 
65 Cuda 340 said:
I agree on the responses posted so far. I think 67Dart's article is useful for alignment specs, but I think you also really need a shop manual to learn how to properly assemble and dis-assemble your front suspension.

I'd add that if one tie rod is lengthened as much as possible while the other is shortened as much as possible (which is how I read what you said), then I'd think your steering box isn't centered. It has to be centered before you adjust the tie rods, and they should be more or less equal length on both sides.

Ride height is adjusted by turning the screws (will take a 3/4 inch socket) coming out on the inside middle of the bottom of the lower control arms. The pivot shaft should be loose in the K frame while you are doing this (i.e., the front nut not fully torqued down). The manual gives specs for the proper ride height. And if you didn't check the condition of the lower control arm bushings before installing them, you should have. If they are worn, your car will never handle very well. Just know that replacing the lower bushings is a booger of a job. If you don't have a shop press, you'll need to farm that job out.

Here's an A body lower control arm with a new bushing installed. Note the rubber around the base of the pivot shaft - fully intact as it should be, not rotten with pieces missing.

View attachment 1715773075
Click to expand...
 
I got a tablet at Dollar General. I took tons of notes. On my 74 my rebuild took weeks, I was taking parts to work to sandblast and paint. I still made some stupid mistakes.
Reassembly… I had a sheet with all torque specs and checked them off as I did them.
On my 68 it went a lot smoother. I didn’t make the same stupid mistakes. Old parts out, new parts in.

2A767F03-1A2B-4A58-B40F-755F4BC98CC1.jpeg
 
OK, so does that mean you just put the cams back where they were before you rebuilt your front end ?
You did take it to a good alignment shop to have it aligned with the new parts installed, right ?
 
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