Torsion Bar ride height adjustments

Torsion Bar ride height adjustments - 07/09/09 03:58 PM

I have a new tire on one side of the car that rubs the upper brace found at the top of the wheel well at the front fender. It only rubs when I bottom out on a dip and oddly, the same tire on the driver side does not. So I thought I might crank the torsion bar up a bit on the passenger side and wondered if anyone knew how many turns of the adjustment bolt translates to how much of a lift.

I cranked it half a turn clockwise but that didn't seem to do much...

Also, this is a 318 B-Body...what kind of ride should i expect if I put 383 or 440 bars in this 318 car?

Posted By: Mr.Yuck

Re: Torsion Bar ride height adjustments - 07/09/09 04:25 PM

It takes a bunch of turns to raise it...

Posted By: SuperCommando

Re: Torsion Bar ride height adjustments - 07/09/09 04:45 PM

Looking for an estimate. If i wanted to get a quarter inch off the ground, what's that translate to? Like 2 full turns of the nut? 4 full turns?

Posted By: Mr.Yuck

Re: Torsion Bar ride height adjustments - 07/09/09 04:48 PM

no idea, they are very fine threads...Here's how I do it. I get the car on a nice flat surface. Measure the hieght at the best bumper line or body line you like. If you like the drivers side ride height than measure it and keep cranking the pass side until you get the same measurement.

Posted By: stumpy

Re: Torsion Bar ride height adjustments - 07/09/09 04:49 PM

I believe you get 1/4" for one full turn. That is a guess because each set up will be a little different due to the condition and spring rate of the old bars.

Posted By: RapidRobert

Re: Torsion Bar ride height adjustments - 07/09/09 07:49 PM

Be aware that changing the ride height(tbars) is going to change your current alignment settings. Dont know how much leeway you have with that though.

Posted By: IMGTX

Re: Torsion Bar ride height adjustments - 07/09/09 07:56 PM

Quote:

Be aware that changing the ride height(tbars) is going to change your current alignment settings. Dont know how much leeway you have with that though.

Also if you do not relieve the tension on the LCA bushing after adjusting the height you will cause premature bushing failure.

Posted By: SuperCommando

Re: Torsion Bar ride height adjustments - 07/10/09 05:38 PM

Yeah thanks for the suggestions. I'm aware that tweaking the torsion bars will alter alignment. However the car has been due for an alignment for a while now so that will all be dealt with eventually. Right now I just need the tire to NOT rub the upper fender support brace.

What is meant by "relieving the tension" on the LCA after height adjustment?

Posted By: 68HemiB

Re: Torsion Bar ride height adjustments - 07/10/09 06:06 PM

Quote:

What is meant by "relieving the tension" on the LCA after height adjustment?

The need to do this is more or less important, depending on how much height change is involved.

The lower control arm pivots at a bushing whose outer shell is fixed into the lower control arm and whose inner shell is fixed around a shaft that is in turn attached solidly to the K member. Whenever the outer shell rotates relative to the inner shell, the rubber between them "winds" slightly. Ideally, the bushing should not be wound at all at normal ride height. After any major suspension work [or significant height adjustment], you should fully tighten the nut that holds the shaft to the K member only after the normal height has been established. If the nut was already tight (as it would be in your situation), loosen it a bit, bounce things around some, and then re-tighten.

Posted By: SuperCommando

Re: Torsion Bar ride height adjustments - 07/13/09 06:51 PM

Okay, so loosen the nut where the words "Control Arm Pivot" point to, bounce the front around to settle thing and re-tighten. Do I re-tighten with the car on the ground and weight on the tires, or tighten with the front end jacked up, weight off the tires?

Attached picture 5349888-lcadiagram.jpg

Posted By: 68HemiB

Re: Torsion Bar ride height adjustments - 07/13/09 07:09 PM

You said:

Quote:

Okay, so loosen the nut where the words "Control Arm Pivot" point to, bounce the front around to settle thing and re-tighten. Do I re-tighten with the car on the ground and weight on the tires, or tighten with the front end jacked up, weight off the tires?

From my previous post:

Quote:

Ideally, the bushing should not be wound at all at normal ride height.

The answer is to tighten at normal ride height, e.g. with the car on the ground and weight on the tires.