Ride height/reindexing project gone wrong.

[crashmy911]

When I did it I removed the spring plate from everything. I think you would run into binding probems if you didn't remove the whole thing.

[Walt Fricke]

Ulrich

We are talking rear torsion bars, right?

In one of your posts you assume that pushing one torsion bar in pushes the other out. But I'm pretty sure these bar ends don't touch. There is a big solid steel slug welded into the center of the torsion tube, with a hole in the center which is splined at each end. I've yet to cut open a tube to inspect one, but it has to be designed so the bars individually bottom. I suppose that with lots of grease maybe you could create a hydraulic action if the hole was drilled through before the splines were cut, but that would be a soft action.

As to what you remove, if you can leave some stuff attached and still get the plate off the bar so you can adjust the plate and bar, why not. You have the two piece plate, right? So you can separate it at the height adjusters and not the camber/toe adjusters?

I pulled everything apart last summer when I canged the T bars and bushings because it seemed the thing to do, but by paying careful attention to angles I didn't have to reset the bars after reassembly. A little ride height adjustment and the corner balance came right in on the scales.

Walt Fricke

[ulrichd]

Walt,
Thanks for the response. I guess my mistery remains. After my last reindexing, I had one torsion bar that only penetrated the spring plate partially while the other side was fine. After dropping the car I noticed that the track on the opposite side, from the partial penetration, was now wider. I am replacing the torsion bar and spring plates on one side, let's see what happens.

Ulrich

[JP911]

Regarding the uneven ride height, did you center the spring plates before you measured the angle and resinstalled? If not, this could be part of the problem. Also, when installing the rear bars, I like to get the bar in the spring plate splines, making full contact, before getting the bars in the chassis splines.

[ulrichd]

Jon,
It's not the ride height that's uneven, it's the track width. All of a sudden my driver side rear wheel sticks out further than the passenger side. I am trying to determine how that's related to the uneven spline penetration.

Ulrich

[JP911]

Could it be that the camber adjustment is as far "positive" as it will go? This would give the appearance of the track being off.

[boyt911sc]

[QUOTE]Originally posted by Walt Fricke
[B]Ulrich

We are talking rear torsion bars, right?

In one of your posts you assume that pushing one torsion bar in pushes the other out. But I'm pretty sure these bar ends don't touch. There is a big solid steel slug welded into the center of the torsion tube, with a hole in the center which is splined at each end.

Walt / Ulrich,
The inner ends of the torsion bars for '78SC come in contact. If you push one torsion bar too far inside, the other torsion bar on the other side will move out. You could actually disengage one TB by using the other TB to push it out.

Test the TB covers for splines fitment with TB out in the car. Measure how far the TB slides into the cover (with splines) for both TB.

TD

[ulrichd]

[QUOTE]Originally posted by boyt911sc
[B]

Originally posted by Walt Fricke
Ulrich


Walt / Ulrich,
The inner ends of the torsion bars for '78SC come in contact. If you push one torsion bar too far inside, the other torsion bar on the other side will move out. You could actually disengage one TB by using the other TB to push it out.

Test the TB covers for splines fitment with TB out in the car. Measure how far the TB slides into the cover (with splines) for both TB.

TD

TD,
Yes, shining a flashlight through the tube I don't see any obstruction in the center. This would indeed explain the symptons I found. Thanks for this information.

Ulrich

[crashmy911]

If your torsion bars are installed and the covers are tightened down and they look the same on left and right maybe it is something else. Look at your camber and toe settings. I doubt they could make that much of a differrence though.

[Dixie]

Picture is what we need.

If one bar was sticking out that far, I doubt the cup would butt against the threaded bosses.

[tiwebber]

Here a picture of the spring plate and cover on my car. It seems to me that the spring plate cannot move out if the cover bolts are tightened down. However, if the splines inside the torsion tube allow the torsion bar to travel farther than the correct position, it seems that the spring plate could move in a bit towards the torsion tube. However, even if it moved enouph to touch and displace the other torsion bar on the other side of the car, I dont see how it could move the spring plate on the other side out more than the maximum that the spring plate cover will allow - that cover is bolted down!

Could it be that the right rear spring plate is positioning itself too far in towards the torsion tube because the inner splines in the torion tube on the right side are broken and allow it to travel too far in?

If that happens, could the right rear wheel appear to be further in than the left? Just some thoughts.

Here's the pic.

[ulrichd]

Tim,
Thanks very much fot taking the trouble. Actually, my spring plate tubes have no covers on them. I had to pop them off way back because my torsion bars were stuck in the tubes and I had to tap them out. This is how I am able to see the uneven bar penetration left to right. As Boyt pointed out earlier the tubes do touch each other on the 78, so if one bar is obstructed it could theoretically push the other one out as you are tightening the covers. I'll try again this weekend with another springplate. This time I'll disconnect the droplinks to take the swaybar out of the equation, which I didn't do last time. Hopefully the unequal reat track was just a badly aligned trailing arm.

Ulrich

[ulrichd]

Well here is the photo evidence. The reason I have no caps on the tubes is that I had to tap the torsion bars out of the spring plates the first time I did this a year ago.

The first pic is the driver's side bar which was flush with the end of tube until I started on the other side and then gradually was pushed out as I tightened the cover plate on the passenger side.

Prior to install I measured the amount that the bars protruded out of the hole (equal) and both bars inserted without problems into the spring plates manually (so no spline problem). I can't see any problem in the torsion bar tube with my flash light.

Is it just the missing spring plate caps? Thanks in advance for your input.

[JP911]

The end caps sit flush with the end of the tube. Are these new/used T-bars? If so, could they be G-50 bars? I know G-50 bars are a different size, just not sure if they are longer.

[Walt Fricke]

Aha - now I see.

First off, this just plain can't affect the track at the rear of your car. Track is the distance between the tire centerlines measured from the contact patch on the ground. The outer holder plates (I won't call them covers to avoid confusion) that the four bolts secure look (pictures aren't totally clear on this) to be where they belong - drawn up tight against the posts that extend out from the body. That means the spring plate is where it belongs. Whatever it is about how the tire sits in the wheel well that led you to believe your track changed is due to something else.

And of course you need to get that one bar back into its holder, and to get the other bar fully seated in its. If you can't drive the left side bar in (which would also drive the right bar out to where it belongs, I have learned from this useful discussion), something is obviously wrong with the splines in the right side holder (or, I suppose, on the end of the right side bar itself). Whatever is wrong you ought to be able to fix by cleaning everything, inspecting, feeliing with your fingers, running scrapers through, using little files, and otherwise finding the small burr or bit of rust that must have caused this and dealing with it and applying a little bit of lubrication. My bet is that this is inside the holder.

I've not had to pull one of the circular covers off of a holder. How does one reinstall that? Will it just pop back in?

Walt Fricke

[Early_S_Man]

Ulrich,

I'm glad we finally have the visual situation at hand!

That torsion bar is sticking out far more than 3/8" past its' normal location ... taking into account the cover normally peened into the trailing arm socket! However, it would seem to be a fairly straightforward fix to me -- even if time-consuming. I again reiterate that anti-sieze compound needs to be applied to the torsion bar splines to reduce friction while putting things back together and to prevent corrosion in the future.

I think you should tack-weld the covers back on the trailing arms in at least three places ... both to prevent torsion bar 'travel' and to protect from the elements in the future!

[ulrichd]

Jon, Warren and Walt,
Thanks for the responses. As I mentioned, I test fitted each torsion bar, well lubed, into the corresponding spring plate manually outside of the car in order to eliminate the splines as a possible culprit. I don't feel comfortable just hammering it back in so I have ordered a used springplate with cover intact from DC Automtive. I will install it on one side first and then do the other and report on the results. Hopefully it is just the fact that the torsion bar that goes in first has no stop with the cap missing.

FYI, I pried the caps off when I found that my torsion bars were stuck in the plates about a year ago. This way I could tap them out. I have plastic caps over the ends to protect th bars from dirt.

Ulrich

[Walt Fricke]

Ulrich

Plastic caps should keep the dirt and mositure out, but what about Warren's advice?

As you have shown us, the caps are all (other than some friction) that keep the bars where they belong. I suppose that doesn't worry you if you drove for several years with plastic caps. But something to think about when you get things sorted out. And have well lubricated/anti-seized bars that slide in and out easily.

Walt

[ulrichd]

Walt,
Now that I understand how important these caps are I will definitely get this corrected. Thanks to all who responded.

Ulrich

[Dixie]

So what happens if you take a dead-blow hammer and tap the extending bar back in? I would think it would drive the other out and self-center the pair. And I doubt the bar protrusion has anything to do with your track difference.

By the way, how duid you measure the track to determine it's off?