Front end problem
 

I recently bought an '85 911. I notice that when I back out of my driveway and crank the wheel all the way to get onto the road, I feel a "thump" "thump" "thump" in the front end. My driveway is on a hill so my front end is higher than the back end.

When I'm on a flat surface I don't feel the same thing. I also don't feel it other than when the wheel is cranked most of the way over. It happens when I turn the wheel to the right or left.

The feeling is very pronounced. That is, I feel it in the steering wheel and someone watching my front end can see the wheel jerk a little.

Does this sound like a problem with the wheel bearing or something else?

Thanks,

Dave

Ball joint? Sway bar bushing/mount? Top strut nut loose?

+1 what DO wrote, it is a process of elimination, check them all.

To check the bearings, raise the car, grab the wheel at 2 and 8, pull and push, if loose, you need to tighten the bearings. If after the adjustement it is still loose, then you need to check the strut, remove the wheel, grab the top of the strut and with the other hand grab the bottom portion of the strut and push/pull, if loose the strut spanner nut needs to be tightened, use a pipe wrench or spanner tool.

While wheel is off check the boots of the tie rod ends and ball joint for tears. check the sway bar bushings for tears or if they are worn.

If all is well then you may need to prepare yourself for new torsion bushings, but before that check the mounting bolts for the t-bars to insure they are all snug.

Jim

I had a "thunking" problem from the front/right for two years. Checked everything...couldn't figure it out. Then one day I noticed there were more threads showing from the driver's side strut than the passenger side strut.

Even though the nut was torqued to proper specs, it was hung up on something (washer, damaged threads?). I cranked down on the nut with an impact gun and problem solved.

Guys,

I checked the bearings and they are tight. I just replaced the tie rods so they should be fine (I had the problem before and after I replace the tie rods). The ball joints look to be ok - no tears in the rubber. The sway bar bushings also look to be ok. When replacing the tie rods I tightened all the bolts that hold in the sway bar.

I tightened the torsion bar bolts and made sure they are torqued to the right spec.

Not sure what to do next.

Thanks for the help.

Dave

Tire rubbing?

Bump steer issue? Is your car lowered at all below spec? (It should be) but the steering wheel jaring sounds like a bump steer issue especially b/c it only happens on an incline/reverse incline. That sloped driveway could be effecting the steering like a bump or speed bump would producing the bump steer symptom...

Worth checking it out.

Lots on bump steer here and in Wayne's books.

Good luck!

My old worn our tires used to do that on tight backing up corners.

How are your a arm bushings?
Could be your torsion bar hitting you a arm if the bushes are shot.

I put on new tires and the problem is either gone or at least much better. I don't understand why.