A discussion of this began on Carl Fausett's thread about polyurethane bushings for the rear suspension: https://rennlist.com/forums/928-foru...ailable-3.html

But rather than post in that thread, where this was a subtopic, I thought I would start a new one to help anyone searching for info on this topc. For reference see my post #33 in the thread above, and other comments in the thread about this issue.

Here is the photo:



You can see the slight bend in the flat spring clearly. I have no idea what caused this. There is no body damage on that side- the only other thing I noted was that the CV joint boots, and maybe the entire half-shaft had been replaced at some point before I bought the car (at ~130K miles, ~190K at present). Obviously I'll be replacing it, although for fun I will also see if I can straighten the spring (which is obviously NOT a fix!) so I can play with my new press. For one thing, I think it will make toe-in adjustment back there easier, the geometry must have been changed somewhat...

Comments welcome, of course!

 

Martin this damage is usually caused by towing the car and connecting the straps/ hooks to the leaf spring otherwise it could be caused by tie down straps used at the dyno
I was watching Louie Ott have his car dynoed in TX
and the tech was wrapping one of the tie downs around this part,
I quickly went and removed the tie down,
and placed it n another area so the part would not be damaged.

 

Is their tire unusual tire wear? Is the car unstable? Can it be aligned?

 

No, No, I'll let you know when I've finished!

 

Stan. that is definitely the most reasonable assumption, given the lack of collateral damage.

 

When I lost my late 90 S4 whilst inspecting the damage at the Porsche dealers a few weeks later when I was back on my feet I was astonished to see such a degradation on one of my arms- sad given the cost of these things. I think the recovery crew who the police called to unblock the motorway had no clue what they were doing. For sure Porsche did not do the recovery and the crash did not seem to explain the signs in this area.

When I parted the wreck I had to throw the part as I considered it was probably meaningless to try and effect a repair and expect the performance to be as per spec. I suspect this is quite a carefully calibrated item.

Regards

Fred

 

99% chance of a crappy tow. I had this happen on an Audi A6 of mine and I told him not to tie to the suspension. He said It's ok I have done this lots of times before. Sadly it didn't look like anything bent when you looked while bending over, but when the tires wore out the inside edge and I had it aligned it was way out. Fvkers! I was pissed.....

 

I suspect you are right!

I've been lucky in a way- unusual tire wear would have alerted me to inspect, but since I haven't experienced any maybe it isn't bad enough to be a problem. It will be replaced anyway.

One odd thing, now that I think of it. I have had wear on the outside shoulder of the PS front tire (this bend is on the DS). I think I have eliminated it with the front suspension rebuild and alignment, but I really won't know if it is totally cured until I replace the tires. Hmmmm...

 

Martin,
I had the same thing happen to me. I owned the car for close to 4 years and had been under it many, many times but never noticed the bend. Right before SITM while mucking around I noticed a very slight bend in the arm that was barely visible, but drove to SITM anyway. When I got back the bend was very noticable! Good news is 928 Intl's half price sale should be coming up (fingers crossed).

 

I hope they have 2!!

 

Had this same thing happen to my GTS with no towing, tie downs, or dyno straps…

You had to use a straight edge to tell it was bent.

The symptoms were the car pulled to the left (the side the bend was on) even after a good alignment and a seasoned alignment guy scratching his head as to why it was pulling.

Replacing the part fixed the pulling.

 

Mine was towed once, or at least pulled up onto a flatbed, without my presence. It was quickly obvious something was wrong as the steering wheel was off centre when driving straight. They probably used the suspension after they broke the towing eye with a side pull...
I would love to quote Helen Hunt's description of a HMO in 'As Good As It Gets'.....
After arm replacement the alignment came back to spec readily.
jp 83 Euro S AT 55k.

 

I didn't think 928 used leaf springs

 

actually a leaf spring is incorporated into the 928 rear LCA,
its the lightest and strongest way to make the part.

Remember these suspension parts came off of Tiger tanks,
so they had to be strong strong and rugged

 

The spring is part of the Weissach rear suspension that increases rear toe during cornering.