Lowering problems?

[MopaR&D]

I recently rebuilt the front end on my '70 318 Duster and the first thing I did when I got the alignment done was I lowered the front end maybe an inch or so by having the torsion bars cranked down. It sat nicely, although now my bump stops were very close to hitting the chassis. I cut off about a 1/4-inch from the tops to make some more room and they seem to hit a lot less, although I can't be sure with these stock low-rate 318 bars. Is this a big deal, or should I not worry about it? Could I cut the bump stops even more to make more room?

edit: Thought I might mention it's a factory disc brake car (4-piston K-H).

 

[yellowdartdave]

Remember that lowering the car from the stock ride height changes a bunch of things.
By cranking down the preload on the bars they are a whole bunch softer.
All the bushings are now in a constant bind as they were torqued down at normal ride height.
The caster and camber are now out of whack due to the lowered ride height. Your camber goes negative as the suspension goes up and positive as it drops. Just jack the front end up and you will see what I mean.
The toe is also out due to bump steer.

Look at any ricer that has lowered his car and you will see that he has a bunch of negative camber and the car is real twitchy.
Lifting a car or truck is just the opposite.
It is a science.

 

[damnimcooltom]

Are you saying that you lowered it after you had it alligned? If you did, just like Dave said, you just un-alligned your car. The bump-stops will be the least of your worries.

 

[6pk2goDemon]

Is this a big deal, or should I not worry about it? Could I cut the bump stops even more to make more room?

Not a big deal that you shaved some off the bump stops.

But like other members responded, unfortunately you've changed your alignment by adjusting the torsion bars. Since it sounds like you just had it done, ask the shop if they will re-check it for you. Ride height on a Mopar should be part of the alignment job anyhow.......maybe you didn't tell them you wanted it lower than stock?

I prefer the lower stance myself......8)

 

[MopaR&D]

I said this in the original post (I guess in a vague way)... I lowered the front end BEFORE everything was aligned; I haven't touched the adjusters since then.

 

[DARTDALE]

What would be the most one could lower an A body by way of torsion bar screws without compromising anything? I have a 72 Dart that I am working with. What have some of yall done in this area?

 

[mullinax95]

Sounds like you didn't have the lower control arms all the way down before you installed the torsion bars and then applied weight to the car. That's why it is so spongy and hitting the bump stops. Whether you changed the ride height before or after the alignment doesn't really matter because the car shouldn't be hitting the bump stops unless the car has been adjusted ridiculous low in the front end.

I would first think of how the torsion bars was installed and if they are in correctly. Just a little turn of the torsion bar makes a difference. Second I would set the car to stock ride height and make sure the car isn't riding on the bump stops. When I was learning about mopars years ago I rebuilt the front end of a 68 Charger. I let the front end down and the front end was very close to the concrete and on the bump stops. I had to remove the torsion bars make sure the adjusting bolt on the lower control was all the way out and the LCA was all the way down. That fixed it.

 

[MopaR&D]

Here's how I finished up the front end (lower control arms/T-bars): First, I backed off the adjuster bolts until I was sure they weren't touching the T-bar 'arm'. Then I bolted the spindle and the control arms together to have a baseline setting (suspension resting on upper bump stop). I then installed the torsion bars with the 'arms' touching the adjuster bolts (had to adjust the bolts just a teeny bit to get the holes to line up right). I cranked up each side about 65 1/4-turns to put in some preload, then I installed the brakes/wheels and lowered the front end to the ground. When I lowered it, both sides hit the lower bump stops, but even then the k-member was still a couple inches off the ground. I then proceeded to drive the car to the shop to get the alignment done.

One other thing, I noticed today that sometimes when going over bumps there is a light "tap" sound that comes from the side that went over the bump. I jacked up one side to get a look at the front-end stuff, then noticed that my wheels had noticeable end play (I could rock the wheel back and forth just enough to notice there was any play at all). It sort of freaked me out, so I put some extra grease on the outsides of the outer bearings and re-adjusted them, this time a bit tighter than when I rebuilt the front end; the end play is still there, but noticeably less. I also noticed that the residual grease on the outside (thrust side) of the bearings was less viscous than the new grease or the grease on the "in" side.

 

[yellowghost]

I will be watching this as I have problems with this also. Mine is set to lower than stock but not excessively I think. And the lower stops are about an inch and a quarter from the frame. Is this ok?

My problem that I have been noticing for some time is a loud slapping noise when I hit bumps. And I am not talking about potholes. Those cracks where large slabs on concrete meet on roads will make that noise. When the roads are not perfectly smooth, all I hear is bang bang bang.... I have changed every joint and bushing and the crossmembers seem to be welded in good. Shock mounts seem to be solid. It only occured to me recently that the banging might be the bump stops to the frame. But I will test this next time I drive it. Also I think that when I removed the torsion bars the last time, I only loosened the adjuster completely and the torsion bars came out with the control arms hanging down but resting on the bump stops. Perhaps the correct position for the control arms to be in is with the bump stops removed and the control arms resting on the frame? I wish my Plymouth service manual wasn't so vague about the torsion bar removal or installation.

 

[jdsduster]

my alignment guy always tells me to set it where you want it and he aligns it fro there.i would do just that

 

[Jim Lusk]

Ok, first off I need to mention that while skimming the answers there is some big misinformation out there. THERE IS NO PRELOAD ON THE BARS. Once there is separation from the LCA bumper and frame you have the SAME LOAD on the bars no matter what ride height you set. All the adjuster does is move the LCA farther away from the frame.

We have run a car with no LCA bumpers to get the ride height lower. It's not a problem, but bottoming out could be harsher.

 

[MopaR&D]

Wow this is an old thread, it's crazy to think I've been messing with my car this long! It's come a long way since back in 2008, dang...

The banging sound when going over a bump could be the shocks; I've also replaced pretty much everything on my car's front end except the shocks and it still makes a bit of a wobbling/tapping sound if I go over certain rough roads. yellowghost looks like your car has enough clearance for the bump stops, if they were hitting you'd feel it more than hear it.

 

[mcnoople]

Have you checked very carefully for cracks in the k-member and/or loose k-member mounting bolts. It might look good sitting still, but roadforce has a way of flexing things.