Sagging rear end

[oadam]

I have a 1972 T that once was a Targa but some PO years ago did a Cabriolet conversion on it. The car has always sagged slightly at the right rear corner (passenger side). It sags about 1/2 at the bumper end and gradually decreases towards the middle and just about evens out by the passenger door. The engine leans a little bit and motor mounts are not level either. Whenever I thought about it I thought it was a matter of adjusting the ride height, but now it turns out that by measuring from the bottom of the torsion bar cover the ride height is exactly the same on either side. The tread wear on tires is even. Is there an issue with the frame or what else could be going on here? Any of your thoughts would be welcome.

[ghnat]

My first though is right rear torsion bar... Maybe cracked/broken. Anyone else have a better idea?

[ianc]

If it were cracked or broken, I'd think the thing would be resting on the stops on that side. You might get away with just reindexing the passenger side. Not an easy job though...

ianc

[mmastro]

I have a similar problem on my 77 930. It sags ~3/8-1/2" on the right rear. There is evidence of it being hit on that side (it's not a perfect car by any means). I had it corner balanced/full alignment and my guy said that it isn't anything to be worried about if I'm not into cosmetics....It's a track car and it balanced out fine. He said he could "dial it level in the rear " but the balance would be off (indicating that the chassis is a tiny bit bent).

[Oldporsche]

I might run it across a frame machine to see if the bottom is flat. (not twisted/warped)

I had a friend that always had a sag to the rear of his 912. He indexed the torson bars equally and correctly. Later he found that one of the rear bars was from a short wheel base car. It had the same dimensions but was unequal in torsion strength.
Just a thought.

David Duffield

[avendlerdp]

Check if the torsion bar tube is not tearing due to rust. I have never seen this first hand but have heard of it happening.

[oadam]

Thanks for the feedback. It looks like the easiest thing to do first is to put it on a frame machine. I wonder how much that will cost? One thing I don't understand is that if there is something wrong with the torsion bar, wouldn't the ride height also be affected?

[ianc]

One thing I don't understand is that if there is something wrong with the torsion bar, wouldn't the ride height also be affected?

Ummm... It kinda looks like it is.

ianc

[oadam]

Thanks, ianc
I am not sure if your reply confirms what I was thinking. The question I have is that if the ride height is exactly the same on both sides, which is the case with my car, can a broken torsion bar be the cause of sagging in the back. Can anyone else confirm this?

[ianc]

The ride height is the same on both sides? In your first post you say the right rear is sagging a half inch...

ianc

[oadam]

That's the problem. In my first post I said the right side of rear end is sagging 1/2 inch, but the ride height is the same on both sides.

[ghnat]

I just looked a little closer at the pic Ole. Guys - does the right side rear light look "off" - like maybe the bumper is not straight or the tail light is not flush.... Hmmmm.

[POKDUB]

You will need to get this up on a ramp for a good visual.

[Bobboloo]

Checking ride height the way you did, from the torsion tube, is the correct way to do it.

Your frame is probably bent. My guess is the car got rear ended.

[quaz]

I think the camera was just tilted a little to the left. Tilt it more to the right and it will be perfect ;-)

[Navaros911]

If the height to the t-bar cover is the same on both sides it it must be the body.

Either slightly twisted or (hopefully) the bumper is not level.

Hate to say, but I think it's the first.

Have it checked and report back.

[oadam]

Thanks for your comments, everyone! It's not just the bumper, the whole hind quarter is drooping on the right side, about 1/2 in. It is hard to tell from the picture, but when you stand behind the car you can see it right away. Since the ride height is equal at both wheels, I think it is either a twisted frame or sheet metal is out of whack, or both. I don't think it is the torsion bar or the ride height would be affected. But, I could be wrong on all counts. It's time to take it to the frame shop and end speculation. Will keep you posted.