Rear ride height

[Marc-André]

Hi to all!

I'm a little concerned about the difference between left and right heights at the rear of my car - left rear tire has definitely touched the fender I haven't measured it yet but if look at the space between the tire and the fender (almost none on the left side) there's quite a difference (say about 1 inch). Have a look at the pictures below.

It seems the radius arm as already been adjusted to raise the left side (you can see a mark where it used to be...); I'm wondering if there is any adjustment left in the eccentric bolt...?

Is it possible to re-align the splines on the torsion bar without having to remove the radius arm and the whole brake caliper and disc ? Could just raising the car and detaching the shock absorber be enough? As usual, any advice is greatly appreciated !

Thanks, Marc-André.

Rear left:


Rear right:


Adjustment:

[Driven97]

Looks like you'll need to re-index, I can't imagine there is anything left on the spring plate cam. You don't have to pull the brake to do this.

Might want to check condition of that torsion bar when you get it apart.

[DRACO A5OG]

+1 Re-index unless T-bars are damaged.

[Flieger]

You will need to remove the 4 rear bolts between the spring plate and banana arm. You may not need to unbolt the rear damper but this depends on how stiff your bars are and the ride height it is currently at. Jack up the car from the engine case, place jack stands on torsion tube inside the longitudinals. Jack up the car, take the spring plate cover off. Place a small jack under the spring plate but just enough to keeep it from springing down when you unbolt the rest of the 19mm bolts on the arm. After that you can let the jack down to take the weight off the spring plate. Then you can remove the spring plate and deal with reindexng.

If you have your handbrake on it will stop the banana arm from moving down if the car is also in gear. I leave it off so I can align the car.

[Marc-André]

Just to be sure, here is my understanding of the procedure (once the car is properly sitting on the stands):



There are two torsion bars; one on each side. So I don't need to disassemble both sides in order to index one side?

After this I will also need to get the car re-aligned ??

Thanks again!

[Flieger]

That's how I did it. I think you must, or at least it will make matters easier if you remove the bolt that attaches the sway bar drop link to the large toe adjustment bolt on the spring plate. I was able to do that without even jacking up the car and it is avtually easier that way because there is no load in the bar then. You will want a creeper to lay on.

Also, before undoing the 4 rear bolts, scribe a line so you can get the spring plate and banana arm lined up somewhat close.

I used the digital level from a Smart Camber setup to fix the rear camber after doing the work. I had a scribe mark from before that got my toe-in close enough. I did not check it though. The camber made a big difference, since the first time I took it out I did not check and found it was 0 or a little positive on one side, -2 on the other. Putting it back -2 on both sides made a world of difference.

Here are some pictures from my project in case they help:

https://www.flickr.com/photos/max_911_fahrer/sets/72157644670892907/

(yes, I look like a teenager but I am 24, and a mechanical engineer (BSME and also my job title))

[johnsjmc]

Before you re index the rear. What is the diagonal fender showing ? Is the front right high, opposite the low rear left? Lowering the front right will raise the rear left if it is. You really need to corner balance these cars as all 4 corners have height adjustment capability. Look up tripod method of corner weight checking before you alter only one corner. And yes a wheel alignment is needed after reindexing

[Driven97]

I have less droop with the larger t-bars, so someone correct me if I am wrong:

You're also going to want to pull the bolt that holds the shock in. Otherwise you're still going to have tension in that spring plate.

The bottom rear torsion cover bolt (the one with the red arrow) has a spacer on it. The spring plate can rest on that spacer and release a fair amount of energy when you pull that bolt out if it's the last one you do, so be careful.

Remember, this is the entire spring force for the rear of the car, so take as much care as you would disassembling a coil spring. It's not hard, just think about what you are doing before you do it.

Oh, and don't forget to re-center the ride height eccentric before you bolt it back together. Much easier to do when it's off the car.

[Flieger]

I have large bars also so I did not need to remove the damper (shock) bolt in order to relieve tension.

You bring up a good point. With the softer bars the plate moves further so the spring plate cover should be taken off first to allow that to happen, and before taking off the rear bolts.

Of course, if you have a second jack like I did then you can take the weight with the jack and then undo the bolts in any order you want, then let the jack down in a controlled way.

I also have corner weight scales and the alignment tools so it was easier for me to do this job.

[sailchef]

You may not need to move the torsion bars.

It almost looks like drivers side lock bolt on swing arm may not have been torqued correctly and somewhere you could have hit a good pothole and swing plate adjustment slid up lowering drivers side ride height.

If this is the case, and the eccentric bolt has swung to the low side you may be able to get away with just raising the drivers side back to its original position. You won’t know until you get in there.

I would check to see if there is any adjustment on that side. To do that you only need to remove rear wheel, pull the shock, and loosen the lock bolt and eccentric bolt while supporting the trailing arm to take weight off of swing arm. There may be some adjustment. I would check that out first, because if this is the case you will not need to have an alignment done as you haven't messed with the toe and camber adjusters.

Just my $.02

[Flieger]

The plate looks all the way in the raised position to me. However, even if the plate could adjust you would still need an alignment for that much ride height change. Changing ride height changes the alignment and changes the corner balance. And changing the alignment changes corner balance and ride height to a degree.

[sailchef]

Originally Posted by Flieger

The plate looks all the way in the raised position to me. However, even if the plate could adjust you would still need an alignment for that much ride height change. Changing ride height changes the alignment and changes the corner balance. And changing the alignment changes corner balance and ride height to a degree.

I stand corrected. Thank you.