front suspension problems..

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sniekamp

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So I got my 74 dart last weekend knowing it needed shocks. It was very easy to bottom out when I pressed on it. So I replaced the shocks thinking that would fix the problem. It helped some but I can still press it down in the front to the point where it bottoms out easily. And when I go over bumps I can hear it making a noise like somethings bumping together. Any ideas?
 
Tell us a little more about the car?

-what engine? /6, 318, etc. Was it a /6 car that now has a V8?
-how many miles are on it?
-what size tires?
-how high does it sit in the front?

The torsion bars that came on most Mopars from the factory are pretty weak, spring rates are on the order of half of what most modern cars are. After a good 40 years, they sag some too. If you car is a /6 car, the torsion bars are pretty small. If it was a /6 car, and now has a V8, the torsion bars may not have been upgraded for the additional weight. Plus, a lot of folks will take advantage of the adjustable height that comes with torsion bar suspension systems and lower the car using the torsion bar adjusters. This is fine (if you can still get the alignment right), but if you do this with stock torsion bars you may end up bottoming out because of the reduced suspension travel.

There's a couple of solutions.

You could raise the ride height of the car by tightening the torsion bar adjusters. Problem with this is that you'll need an alignment afterward. And, of course if you're already at stock ride height in the front raising it more will make you car look even more like a taildragger, and it'll handle like crap. Basically, this is only going to work well if someone else already lowered the car with the adjusters and you're just returning it to stock height.

Realistically, you probably need new torsion bars. If you've got a /6 car, you may be able to get away with swapping in some larger diameter V8 bars off another A-body. Problem with this is, those are 40 year old bars too. So, it may be time to bite the bullet and buy new torsion bars. Something in the .96 to 1.03" range is what most people like. The car will handle better, and you'll cure the bottoming out issue. Unfortunately, you'll still need an alignment. And, if it needs new torsion bars, you should probably consider rebuilding the rest of the front suspension if it hasn't already been done. Bushings, ball joints, etc.
 
That's all good to know. The car is completely stock. It has a 318 and 75,000 miles. Never had a /6 in it. So im probably looking at new torsion bars? The steering in it is okay but maybe I could redo that as well. Is relpacing a torsion bar a big job? Its also got 195/75/14 tires on it.
 
So this is the car?

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Doesn't appear to be lowered in the front, so, with 75k miles I'd guess that new torsion bars are probably in order. Didn't realize it was a 4 door, so, that would make it heavier than its 2 door counterparts too.

How big of a job the torsion bar replacement is kinda depends on the car. I just pulled the torsion bars out of my EL5 dart, they practically fell out. Still had all the factory grease in the anchors! But, its a California car that was garaged most its life- no rust on it ANYWHERE and everything was well lubricated. The torsion bars in my Challenger, on the other hand, were a struggle. The torsion bars and anchors were pretty nasty with road debris and rust, and it took several hours and many large hammers to finally break them loose. It should be a straightforward job, but the condition of the bars and anchors makes a huge difference.

The easiest way I've found to remove the torsion bars is to drop the lower control arm off the spindle and remove the strut rod and control arm nut. Then you can use a dead blow hammer (not a steel hammer!) on the LCA to drive the torsion bar back and out of the anchor (after removing the clips of course). That way no special tools are needed. Only problem about that is it basically means you have to pull the front suspension completely apart. Which is fine if you're rebuilding the front end, and a lot of extra work if you're not. Otherwise, you'll probably want to buy a torsion bar removal tool, or make something similar yourself, to give yourself something to drive the torsion bars out with.

More than likely, if the torsion bars are that worn out, so is everything else in the front suspension. You already changed the shocks, I would guess its probably time to replace all the bushings and ball joints too. So, it gets to be a big job pretty quickly.
 
If you would be getting new torsion bars. What I would do is put it up on stands back the adjuster bolt all the way out so there is NO tension on the bars. And cut them out.
 
Yeah that's my dart. I talked to an older guy at the local auto parts store and he said it might just be that the torsion bars are out of adjustment. Is that possible? Seems like a simpler fix. Where are the adjustment screws?
 
The reason I say that is because the steering in the car is not bad and would rather not tear the front end apart.
 
sniekamp said:
The reason I say that is because the steering in the car is not bad and would rather not tear the front end apart.
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I'm guessing the Torsion bars should have some life left in them. The adjusters are located right on the bottom of each lower control arm. I'd adjust them 1/2 turn at a time and check it. Unfortunately, You need to jack the car up by the frame to take the weight off the suspension.
 
sniekamp said:
Yeah that's my dart. I talked to an older guy at the local auto parts store and he said it might just be that the torsion bars are out of adjustment. Is that possible? Seems like a simpler fix. Where are the adjustment screws?
Click to expand...

OwdKasd said:
I'm guessing the Torsion bars should have some life left in them. The adjusters are located right on the bottom of each lower control arm. I'd adjust them 1/2 turn at a time and check it. Unfortunately, You need to jack the car up by the frame to take the weight off the suspension.
Click to expand...

The only problem I see with this is that your car does not seem to be especially low in the front. Torsion bars can sag, and adjusting them with the adjusters can help that. But, when the bars sag the front end of the car sits lower.

It's a common misconception that cranking down the torsion bar adjusters increases your spring rate or preload. It does no such thing. It will raise the front of the car, which will increase your available suspension travel. Which might keep you from bottoming out. But, you'll be riding higher than stock in the front, because your car already appears to be at stock ride height. And, you'll still need an alignment.

I'm not saying it isn't worth trying, but your torsion bars are 38 years old and have 75,000 miles on them. Let's just say I wouldn't be surprised if it didn't fix your problems.
 
Thanks for all the info, ill try adjusting the bars first, but it sounds like it may just be time to put a fresh set under it.
 
Check the condition of your leaf springs to make sure they are not sagging. If they are not sagging, you can use the ride height adjusting bolts in the LCAs to level the front end. The torsion bars do weaken with age, just like any spring.

Don't forget to have your alignment checked when you are finished adjusting the ride height.
 
FISHBREATH said:
Check the condition of your leaf springs to make sure they are not sagging. If they are not sagging, you can use the ride height adjusting bolts in the LCAs to level the front end. The torsion bars do weaken with age, just like any spring.

Don't forget to have your alignment checked when you are finished adjusting the ride height.
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Just a point here, the springs don't actually "weaken". The spring rate remains the same (true of torsion bars and leaf springs). However, the spring will sag over time. On leaf springs its easy to see, the arch decreases and the springs will look flatter. Torsion bars don't really look any different, although they have their own equivalent to de-arching. While this effects the ride height, it doesn't change the spring rate of the bars.

I know its just a technical nit picky point, but it seems like its a pretty common misconception.
 
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