polecat702

Is it just me or has any one else had the right front fender crack in the fender lip? Both my 87, and 89 have had a crack about a 1/3 of the way up in the lip. What the hell is causing this?

M. Requin

Same thing on my car, my guess would some kind of fatigue caused by vibration. On my 86.5 at least the structures under the fender and splash shields are not symmetrical, which is why, if vibration is the cause, the crack would not necessarily be on both fenders. And that is most definitely a WAG!

Bertrand Daoust

No crack on mine - for now.
Nice observation Martin.

Livio928

My 89 has it on the driver side fender as well.

SeanR

Have any of you guys rolled the front fenders? The only car I saw these cracks on, they were rolled to fit the larger tires.

Livio928

I have to say that i didn't notice the cracks until i started to DE with Hoosiers which leads me to believe that it could be the added stresses put on with the higher g forces in the corners. The fenders were not rolled and I originally thought they cracked because i did NOT roll them. I guess there must be some type of stress or weakness in the fenders during that production time frame.

Any other ideas??

SeanR

That does remind me. Had a customer who put some sticky tires on his '80 and went autocrossing. The compression put the tire rubbing against the fender and it did start to buckle and crack. The fender had a small ridge on the inside/non-rolled portion and that is where the crack started.

Sad really, the car was pristine until that point.

Bob in Socal

I think the aluminum cracked due to stress

polecat702

I just thought it was weird that the crack is in the same place on both of my 928's. It's just the lip for now, and I didn't want to pull the fender to weld it, and then have to paint the fender, might as well paint the entire car.

I was wondering if laying some epoxy inside the lip would work as a temp repair till I repaint the car. I want to fix all the little things on the car before I have it painted.

My fenders aren't rolled either. It was like this when I bought the car, same as the 87.

M. Requin

My theory: shot to hell...

The Fixer

Edit:
The fenders are bolted to a very stressed part of the car.
Mine has no cracks at all, still in bare metal and my car has not ever been tracked, 65k miles.
I wonder if harder front suspension setups help make this fatigue happen.

The Fixer

I went out to look at the wheel housing without fenders attached. I think when cornering hard and the upper housings flex, the lower fender support in front of the wheel would not move nearly as much causing the fender flex. Thus causes the fatigue over time.

I will attach my fenders somewhat loose (bolt only loose with nylon lock nuts) at these lower points, with (4) 1/8" thick rubber washers, 2) on the upper side of this lower support and (2) below them metal washers over them.

This should allow for a little movement.

Alan

Can someone post a picture of the cracks? Not understanding what this looks like?

Alan

polecat702

Alan, here's a photo of the crack in the lip of my right front fender.

JWise

For those not viewing on a big screen, let me resize.