Hi, folks...at speeds under 40 mph, when I hit a bump, the rear of the car does a quick sashay to the left. It handles just fine at highway speed. I'm guessing that when I replace the shocks/struts, I also need to replace some bushings?

 

Check for looseness in the long pin that runs through the lower A-arm. There are nuts on both ends and some (mine) tend to loosen.

Classic "bump steer" is due to lowering the front and changing the geometry too much, btw. Is your front end lowered more than an inch?

 

A good thing to do right now would be to get it up in the air and check every suspension component for play and report back here .... it may be minor ... but on the other hand ? .. don't risk your safety by waiting.

BTW add your car details to your signature to save us asking

 

The Most Common cause of that problem is mis-fitting the cupped washers on that long bottom bolt/rod. There are pictures and a diagram here someplace, but the description is that those cupped washers sit in mating cupped recesses in the lower control arm where that bolt passes through. They keep the bolt centered in the hole passing through the casting. The other Most Common cause is that the nuts on the ends of that bolt/rod aren't tightened correctly. That allows the bolt to move around some even when the cupped washers are installed correctly.

 

Always add car details.

I ignore signatures in the thread-viewing preferences. It's a waste of space (and brain time) to see the silly things people put there. I assume that I'm not alone.

 

Thanks, all...the car is not (and never will be, as long as I own it, unless a compelling reason exists to alter the factory suspension) lowered at all. I'm not currently driving it, as I'm shopping around for suspension pieces, including the lower ball joint mount...will probably buy from 928 Specialties, as I like to support businesses that support us. I'll put it up on the rack next time I take it to the shop.

EDIT: Adding details to sig...be right back, lol...

 

Bob, I take it those washers are supposed to face inward, correct? (Bottom of cup toward center portion of bolt?)

 

They face the direction of the cup that they sit in...

 

Great...just took a quick look under the car. It appears at least one of those washers has been replaced with a flat washer (they should look dished, right?), and I can see evidence of movement around the washer. Friggin' bozos...I can see it now..."wow, this here washer's all bent...better replace it..."

 

*heh*

Sorry...laughing WITH you on the "this looks bent!"

 

Out of curiosity, have you measured the ride height. If not the springs may have sagged over the years and may need to be adjusted to bring back within spec. As the 928 has ride height adjustable coilovers from the factory the car's suspension doesn't have to be modified or altered to lower or raise it.

 

Thank you, Simon! The more I learn about this car, the better I like it, and the more I realize what a terrific car Porsche built for those who can appreciate great engineering...

 

There's one flat washer and two cone washers along that pin.

 

Okay, from front to rear, how are they stacked?
Like so? +)---------------([+
(With the + sign being the nuts/bolt heads, and parentheses being the cup washers?) If so, they may just need tightening. And btw, does anyone know offhand what the stock ride height is and where to measure it?
Thanks for the help (and your patience!!).