Tim Wasmer

Gang:

As most of you know I have had to replace my front differential. Well after replacement it still was making a gearish noise up front. I drained all fluids again and refilled to no avail. I put the car up on all 4's to drive it and see if I could better pinpoint the sound. It was definatly coming from the right front. AND when the wheels were spinning the rt front was going slower than the rest of the wheels. When the clutch was engaged and the wheels allowed to "coast" it stopped almost immediatly.

Upon digging deaper and doing some more research it looks like my rt front wheel bearing is shot. And probably HAS been for a while. Because when it went it was popping in the rt front wheel. The added drag of the wheel bearing and the OLD fluid in the diff probably conspired to cause the failure.

Net of this is, check your wheel bearings

Ray Calvo

Wheel center cap/center hub didn't feel hotter than other side? Always thought this was one way to check for bearing problems (besides the standard way of rocking the wheel by grabbing the top & bottom of the tire and trying to move it in and out while it's up in the air).

Tim Wasmer

The right front was smoking when the diff failed. But the smoke seemed to be coming from the diff area but it was hard to pinpoint in the wind.

Tom Trew

Here is a picture of one of the front bearing races off of my 97.

Car has about 35k miles, most of it on the track. The interesting thing is that the good old "rock the wheel" test did not indicate any problem. The first symptom was a grinding feeling in hard corners. When I pulled the brake pads and slowly rotated the hub, I could hear a faint click-click as the ***** crossed the bad spot. I got suspicious and had the bearings pressed out, and that is what I found. The good news is the bearings are not expensive and my mechanic charged 6 hours to do both sides. Of course I had to realign the car afterwards. At any rate, don't rely on the "wobble" test we used for the early cars, the 993 with the pressed in bearing is a different animal.

Tim Wasmer

That is what I hear. Take off the calipers to allow for the best "feeling" of the bearings. The bearing is $40 and will be my weekend project.

Tom Trew

You don't really need to remove the caliper, just pull the pads. The idea is to get the dragging pads out of the equation, and if your garage is nice and quiet, you may be able to hear the problem. Ideally you will hear absolutely nothing as you rotate the hub. Any type of click probably indicates a failed race. Mine were very discolored from heat, which was probably the first step in the failure process. Unfortunately, these are not bearings you can periodically repack, so periodic replacement is the only option.

993Porsche

Is there a DIY writeup for the replacement of the front wheel bearings?

Martin S.

is n o piece of cake. You have to pratically take the LSA apart to get the old bearings out.