Drop Spindles

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jar84203

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I am installing 2 inch drop spindles on my 71 duster with a 73 disc conversion. Since the caliper and splash shield are relocated to make room for the spindle, the shield is not interfering with the mounts for the lower ball joint. Does anyone know of any aftermarket ones that will work, or will I have to modify these?
 
Just leave them off. They serve no real purpose other than to trap dust close to the rotor and impede cooling airflow. In theory they would keep some splashing water off the rotor, in reality, not so much.

Most (if not all) new cars don't even come with them. I haven't had splash shields on my daily driven Challenger since I installed the magnumforce drop spindles over 2 years, and nearly 20k miles, ago. No issues.
 
Makes sense...thanks. Any other issues encountered with the drop spindles?
 
I never installed my shields with the 73 conversion. Post up some picture of the car ride height when done.
 
The only "issue" I've had is the relocated tie rod end. Usually, if you run 17" rims the tie rod end actually fits inside the lip of the rim, allowing more backspace. With the drop spindle, it basically maintains the same relationship to the 17" rim as the stock tie rod does with a 15" rim, ie, its pretty much the limiting factor for backspacing.

That said, it STILL clears my 17x9" rims with a 5" backspace and 275/40/17 tires. So, not really an issue for most folks.

And that's on my e-body Challenger, btw. Not sure that set up would fit an A-body anyway.

The other issue to consider is bump steer, which the drop spindles increase because of the relocated steering arm. Here's the deal though- I know that the bump steer has been made worse numerically, but I haven't actually noticed it driving the car. And I doubt most people would. Now, if you're road racing, it would be something to think about.

I do plan on taking the drop spindles off my challenger when it gets torn down and restored. I run them because I also run 1.12" torsion bars, and I couldn't get my car low enough using just the torsion bar adjusters. When the car is torn down though I'm going to clock the anchors in old school circle track fashion, so the drop spindles won't be necessary.

IMG_3018.jpg
 
Never thought about tie rod interference. It has stock 14" wheels. Problem?
 
jar84203 said:
Never thought about tie rod interference. It has stock 14" wheels. Problem?
Click to expand...

Not likely. The backspacing on a stock set of 14" rims shouldn't put you anywhere near the tie rods.
 
72nblu could you elaborate on clocking the torsion bar anchors. I've heard of this but never fully understood the procedure. I'd like to be able to go low with the large 1" bars I have while keeping the stock spindles.
 
rudmover said:
72nblu could you elaborate on clocking the torsion bar anchors. I've heard of this but never fully understood the procedure. I'd like to be able to go low with the large 1" bars I have while keeping the stock spindles.
Click to expand...

For 1" bars it likely won't be necessary. In fact, for most of the larger bars offered now it isn't necessary, as they come with something other than a 30 degree offset.

Stock torsion bars have a 30 degree offset to preload the suspension, but as the bars get larger less offset is needed. Some of the really large bars have no offset at all. Still you'll find now that more people complain about not being able to get HIGH enough with newer torsion bars (like hotchkis) because they've reduced the offset so much. Do a search on the Hotchkis torsion bars (1.03") and you'll already find a thread or two about people not being able to get the car all the way back to stock ride height (good if you want lowered, bad if you want stock).

At any rate, I'll explain anyway. At least what I know. Obviously, the torsion bars have to be out of the car. The torsion bar anchors have to be cut out of the crossmember, then rotated or "clocked" the desired amount. Before you do any cutting, you'd want to index the anchors, ie, mark 12 'o clock and any other degree amounts you'd want to keep things straight. Then you'd want to make a nice clean cut (blair hole saw?) to get the anchors out. You'd then turn the anchors by the amount you want to alter the offset. For example, if you want to go the full monty for stock bars, clock the anchors 30 degrees. That will basically turn your 30 degree offset bars into 0 offset bars. You'd then have to re weld the anchors into the cross member. The result would be that no matter what your torsion bar offset is, the effective offset would always be 30 degrees less. Of course, you could clock it any amount you want. Mopar performance used to offer a kit to do this, it included reinforcing plates for the anchors, directions and possibly even a degree wheel for getting it right. I saw a picture of the kit once...

BUT, and its a big BUT, if you do it this way you're stuck with big torsion bars. Switch back to stock bars and you won't be able to get enough adjustment to get your front end off the pavement. Which is why this was primarily done to race cars, because if you switched in 1.25" torsion bars it was the ONLY way to lower the car at the time. Don't bother for 1" bars, you won't need it. In fact, don't bother for most of the larger bars made now, because their offset has already been altered so the ride height is in the right place (or close to it). I'm not sure what happened with my bars, but I actually am beginning to think that there was a manufacturing problem with this set. And I may just buy a set of Hotchkis bars and call it even, although I actually like the 1.12" bars in my challenger, so we'll see.
 
Thanks I did'nt meen to hijack this thread but I appreciate you explaining. I suppose that I'll have to get the front end done i.e. complete rebuild then just see what I can get as far as lowering before I consider doing this procedure. It may be worth the flow for some drop spindles.
 
I have the Fatman spindles (no others available at the time) and have had no issues either. Left the splash shields off.
 
Hi, what about lower ball joint? If I order Magnum force spindels do I need some kinda special balljoints? Already have a stock -73 front end. Thanks!!
 
72bluNblu said:
For 1" bars it likely won't be necessary. In fact, for most of the larger bars offered now it isn't necessary, as they come with something other than a 30 degree offset.

Stock torsion bars have a 30 degree offset to preload the suspension, but as the bars get larger less offset is needed. Some of the really large bars have no offset at all. Still you'll find now that more people complain about not being able to get HIGH enough with newer torsion bars (like hotchkis) because they've reduced the offset so much. Do a search on the Hotchkis torsion bars (1.03") and you'll already find a thread or two about people not being able to get the car all the way back to stock ride height (good if you want lowered, bad if you want stock).

At any rate, I'll explain anyway. At least what I know. Obviously, the torsion bars have to be out of the car. The torsion bar anchors have to be cut out of the crossmember, then rotated or "clocked" the desired amount. Before you do any cutting, you'd want to index the anchors, ie, mark 12 'o clock and any other degree amounts you'd want to keep things straight. Then you'd want to make a nice clean cut (blair hole saw?) to get the anchors out. You'd then turn the anchors by the amount you want to alter the offset. For example, if you want to go the full monty for stock bars, clock the anchors 30 degrees. That will basically turn your 30 degree offset bars into 0 offset bars. You'd then have to re weld the anchors into the cross member. The result would be that no matter what your torsion bar offset is, the effective offset would always be 30 degrees less. Of course, you could clock it any amount you want. Mopar performance used to offer a kit to do this, it included reinforcing plates for the anchors, directions and possibly even a degree wheel for getting it right. I saw a picture of the kit once...

BUT, and its a big BUT, if you do it this way you're stuck with big torsion bars. Switch back to stock bars and you won't be able to get enough adjustment to get your front end off the pavement. Which is why this was primarily done to race cars, because if you switched in 1.25" torsion bars it was the ONLY way to lower the car at the time. Don't bother for 1" bars, you won't need it. In fact, don't bother for most of the larger bars made now, because their offset has already been altered so the ride height is in the right place (or close to it). I'm not sure what happened with my bars, but I actually am beginning to think that there was a manufacturing problem with this set. And I may just buy a set of Hotchkis bars and call it even, although I actually like the 1.12" bars in my challenger, so we'll see.
Click to expand...

Sorry, more hijacking. Not entirely though as its on topic. When you say its in the right place, do you mean lower than factory? My impression has been that bigger bars let you lower somewhat more by reducing the potential for bottoming out the suspension, but you will be riding with a lot of your suspension travel "used up", already close to the bump stops. My reason for asking is I'd like to get my 69 down to where part of the front tire is covered by the fender. I want bigger bars for better handling, but not sure if I also will need drop spindles.
 
Idaho said:
Sorry, more hijacking. Not entirely though as its on topic. When you say its in the right place, do you mean lower than factory? My impression has been that bigger bars let you lower somewhat more by reducing the potential for bottoming out the suspension, but you will be riding with a lot of your suspension travel "used up", already close to the bump stops. My reason for asking is I'd like to get my 69 down to where part of the front tire is covered by the fender. I want bigger bars for better handling, but not sure if I also will need drop spindles.
Click to expand...

Yes, lower than factory.

Here's the thing. Larger bars have much higher spring rates. Higher spring rates mean less suspension travel, regardless of how much is available (distance to the bumpstop). So, if you double your spring rate (like most 1" bars do vs stock) then you can pretty much figure on using half as much travel in most situations. So, even if you lower the car and "use up" some of that available travel, it's not a problem because you still won't bottom the suspension out.

I'd be surprised if my duster has 2" from the shorty poly bumpstop I put in there to the frame. But with the 1" torsion bars, I've never even been close to bottoming the suspension. Tops of the tires are just covered, and they're fairly short 225/60/15's.

As far as needing drop spindles to get low enough, it will depend on how the torsion bars are offset. Some are offset more than others, the 1" JS bars are 0 offset, and my adjusters are pretty close to the bottom of their adjustment on my Duster, so I can't go much lower than I am now. Hotchkis bars are offset to the point that some guys can't even get to stock ride height with the adjusters all the way in. just depends on the bar.
 
72bluNblu said:
Yes, lower than factory.

Here's the thing. Larger bars have much higher spring rates. Higher spring rates mean less suspension travel, regardless of how much is available (distance to the bumpstop). So, if you double your spring rate (like most 1" bars do vs stock) then you can pretty much figure on using half as much travel in most situations. So, even if you lower the car and "use up" some of that available travel, it's not a problem because you still won't bottom the suspension out.

I'd be surprised if my duster has 2" from the shorty poly bumpstop I put in there to the frame. But with the 1" torsion bars, I've never even been close to bottoming the suspension. Tops of the tires are just covered, and they're fairly short 225/60/15's.

As far as needing drop spindles to get low enough, it will depend on how the torsion bars are offset. Some are offset more than others, the 1" JS bars are 0 offset, and my adjusters are pretty close to the bottom of their adjustment on my Duster, so I can't go much lower than I am now. Hotchkis bars are offset to the point that some guys can't even get to stock ride height with the adjusters all the way in. just depends on the bar.
Click to expand...

Thanks that's very helpful. Maybe I can get away with just some Hotchkiss bars and save some $.
 
Another question. With potential geometry change with large bars and lowered suspension, is there a need for offset control arm bushings?
 
Idaho said:
Another question. With potential geometry change with large bars and lowered suspension, is there a need for offset control arm bushings?
Click to expand...

Even without the modifications, they will still help correct caster. Ideally, control arms with the adjustments built in or with additional adjustments are preferred to the bushings.
 
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