Hi Guys-
I got my jag back from firestone. I had them put two new tires on it. These guys are the ones that told me the lugs were 'single use'.
You can understand why I'm skeptical about anything else they tell me.

I notice that when I put on the breaks, the front wheel or wheels seem to shudder. My friend was driving beside me and said that at least the passenger side wheel seemed to shudder and bounce a bit when I brake. It was every pronounced. I had to brake VERY carefully.

The Firestone guys said that it was the front wheel bearings. In fact, they said all four wheels needed new bearings.
Is there a way for me to test their diagnosis? I just don't trust them.

-Thanks-
-C

 

Easiest way is to jack up the car with the wheel on, and try to move it from 3 and 9 o'clock positions (and up and down). Basically, looking for play when the wheel is off the ground. You shouldn't be able to move it back and forth like that, so if it's got play, it's likely to be bearings.

 

Sounds like WARPED ROTORS to me!!!!!

bob

 

eh, just take the rotors off. Totally un-needed. Besides, I'm surprised that shop hasn't said they're were single use pads too!

 

Good god man!! That place just keeps trying don't they? Tell them you want a valve adjustment. And yes, theoretically they can be adjusted.

Anyways, both of the rear wheel bearings do have play in them from day one. The play is at the 12 & 6 o'clock position. As far as the brakes, go with what your told by someone you can trust which is your friend. Put pads and rotors on the front.

 

Maybe they just didn't tighten the one time lugs nuts??

 

+1

 

From what you have described, the first thing I would do is loosen all the lugs and tighten them to torque specs in the proper order/sequence.. There is just no telling how those clowns put the wheels back on, and a lug that is stripped or loose could be at fault. Jamming them on with an air wrench above torque in a circular pattern could cause the wheel to be seated poorly. Since it occurs when braking, it is likely associated with the braking system, so check that out. It may well be the rotors, but if the problem did not exist before the new tires (I assume the fronts are new, or at least the front wheels were removed and put back on) then probably not, unless they dropped the car on the rotors and bent them. Check the calipers to see if the pistons are sticking when the brakes are applied. Check the brake lines for leaking and/or bulges and cracks. The brake line connections may have been loosened, and you may have air in the system, thus needing to bleed/flush. Look for anything the tire morons may have broken while working. Lastly, you may have been sold some defective tires that are out of round, or otherwise faulty. If you just bought two tires for the front, you can temporarily rotate the rear tires to the front and see if it still happens. If you bought all four, it is still possible that all four are bad. Regardless, I would make a wide detour around that particular shop if you need any work done!

 

DEFINITELY warped rotors! I did the wheel bearings on my XJR a few months ago and it didn't care whether I was driving or braking, the wheel would wander and grab every rut in the road. Replace the rotors and pads and your problems will go away. And as a dose of preventive medicine, STAY AWAY from Firestone!!

 

Turns out there is loads of 12 o-clock - 6 o-clock play on the drivers side. Less on the passenger side.
I got the new bearings in. They came two in the box. Does this car only have one bearing per wheel? Sounds like a stupid question, but I'm asking anyway. ;op
-Thanks
-C

 

Front or rear bearings?

Fronts are a single sealed unit on each side, rears are a pair of angular contact bearings per side. I believe the inner and outer are different from each other in the rear. Do you have JTIS or the workshop manual?

If there is lots of 12-6 play on the rear wheels, look at the u joints and diff output shaft to see if the play is coming from there instead.