One corner sagging...why?

[Colby]

Ok, here's the scoop. I put on '74 exchangers and as a result of the lighter rear end (I also pulled the A/C), the ride height jumped up about 1/2-3/4". Well, it was already too high, and this extra amount made it so something had to be done (I was at about 26.5"). So I did the infamous torsion adjust. Inner counterclockwise one notch, outer clockwise once. Same for both sides. I also penciled before and after lines on each side and made sure they were the same. I lowered it and it was about where I wanted it, so I then lowered the fronts to match. Well, it now appears the driver side rear has settled about 1/2" lower than the passenger rear. I tried fiddling w/ the passenger front to compensate, but it did not take care of it (lowering it way low made it so it was only 1/4" off). I have a ride height adjustment tool on its way; hopefully I can fine tune it out (BTW, it's an '84). It may have always been like this and I never noticed until it was lowered, or more likely I did something to screw it up. So my question is: what all can make one side sag more than the other, and what are the remedies? So far, I have thought of the following:

1) Torsion bar is tired.
2) Bushings are worn.
3) Torsion bars aren't lined up the same.

What is everyone's thought on this?

Oh, question #2... I have mega wide wheels back there (17x9.5" 255/40/17). The reason I want to get it back up as high as the other side is 1) it looks funny and 2) it's rubbing on the inside fender. Raising the height will affect how often it will rub...what else will? Stiffer torsion bar, stiffer shocks, sway bars? I'm sure all will help a little..which would help the most. Even the other side is rubbing a little. I'd like to keep them at this height (25" rear), but need to minimize the rubbing.

Thanks in advance.

Colby

[Clark Griswald]

Don't sweat it. Your car is fine. You need that adjusting wrench. Once you get it, you can dial in the ride height easily. That is provided you have some range left.

If you have oem adjustable spring plates, the torsion bar project should not be started unless you have the special wrench. You really need it to do the job.

Worn spring plate bushings should always be replaced when you have the tbars out. The job is easy if the spring plates are already out anyway.

You didn't say what year your car is or how many miles. My '86 had visible wear on the bushings at 85k miles. My '77 had extreme wear on the bushings at 235k miles.

I have done this job on both.

Get the wrench and you will be fine.

I would recommend corner balancing, then a 4 wheel alignment after you get the height dialed in.

The rear camber adjustment will have a big impact on tire clearance. You can easily move the tire sideway in/out over an 1 inch with camber. When you lowered the car, you hosed up all those settings.

Check out the tech article I wrote on this whole procedure.

I recommend that when you go in for the 4 wheel align, that you stand there and make sure it is done correctly for all 3 front wheel settings and both rear wheel settings. 4 wheel aligns seem to be a favorite place for shops to cut corners. They set the toe and send you on your way.

I have had several shops try to tell me that 911s don't have camber and caster adjustments up front. Most people get taken because they don't know any better.

A proper alignment will make a huge difference after you get these other items sorted out.


------------------
Chuck Moreland '86 Cab - "Sparky", '77 Targa - "Sweet Pea"

[This message has been edited by Clark Griswald (edited 08-12-2001).]

[Colby]

The car is an '84 with (get ready for this) over 200K miles (and runs great!). I actually did have an alignment done after I lowered it. It wasn't until after the alignment that I noticed one corner was off. I had them max out the rear camber (-1.3) to help with clearance. And you guessed it; they told me they could not change the caster up front so they didn't mess with it. How is it done; I'll take it back to them and have them do it right (after I muck it up anyways by altering the height).

Colby

[Clark Griswald]

Setting caster up front is done by loosening the allen head bolts that hold the plate that the top of the strut mounts to. You loosen the allens, then slide the strut top back and forward to get the caster.

these are the bolts #14 in the following diagram:


The front camber is done the same way, only move the strut top side to side.

Factory camber on the rear I beleive is -1 degree, so your -1.3 is really not that much. If you want cornering performance it is common to run -2 degrees or more.

If you have 200k miles, you can bet your spring plate bushings are worn. Did you inspect these when you pulled the plates out?

Here is a picture of mine with 85k miles.


This is what the should look like, nice and square:



My '77 with 235k miles had more than double this much wear.

[Colby]

Ok, judging by the two pictures (those were TREMENDOUSLY HELPFUL BTW) I can confirm that my bushings were VERY worn. However, the torsion bar cover was in there very snug? What symptoms would these bushings being worn cause?

Colby

[Clark Griswald]

Even with the worn bushings, the spring plate caps will still be snug and take some effort to pull off. This is because the bushings only wear on the side that bears the weight. The other side will stay square. In fact, the two pictures I showed above are opposite sides of the same bushings.

The result of worn bushings is sloppy positioning of the spring plate. Instead of firmly holding in place, it will mush around a bit. Consequently, the car will not hold its alignment settings well under cornering loads.

Bushing wear will lead to sagging only by the amount the bushing is worn. So a badly worn bushing might only contribute 1/4-3/8 inch of sag. And likely both sides will wear about the same amount.

That is not causing your height problem though, you just haven't adjusted it properly yet. You need that wrench.

If it was my car, I would pull those spring plates out and change the bushings. Then set your ride height again. The good news is you can mark the existing angle (which is about right) so it should be easy to get the tbars in right the first time.