I have an appointment tomorrow morning to get 4 new tires. The tires on the car have tread but they are 8 years old and showing some cracks. They still ride good but I feel like it's time.

I rotated the tires a year ago and got front end vibration for about 150 miles and then perfectly smooth again. I rotated again about 6 months ago and got worse front end vibration than before. I gave it 900 miles but it never got any better; rotated them back. Nice and smooth again.

Tire wear looks even and the car tracks perfectly straight. I scheduled a 4 wheel alignment for after I pick up my tires. Was that necessary?

Thanks

 

Doesn't hurt. But I would be cautious of a bent rim on the rear wheels. Balance should catch it.

 

It's very possible you have a bent rim. If it was in the tire,, depending on the condition, the balancing should have remedied the problem. When you go in to have the tires replaced, they should be able to see if there is a bend in the rim when its spinning to be balanced. When I was at the dealer in Houston, we had a balancer that could do OEM matching, meaning you match the low/high spot of the tire to that of the rim, making it as true as possible, minimizing the amount of weight you have to put on. If you look at the tires, and see alot of weight on there, then either there is a problem with the rim or the tire. You should definitely get an alignment after the new tires, the alignment settings will be different, mostly because there is new tread. As the tread wears, the geometry changes. Even the slightest amount of wear can mean the biggest difference of whether you're in the green or red zone.

 

I've never had them balanced, they were on the car when I bought it a year ago and I just rotated them myself. If it was a bent rim, would it have gotten better after 150 miles like it did the first time I rotated?

The spare is an identical rim to what's on the car. If one does turn out to be bent I'll have the spare tested and if it's true, switch them out.

My concern with the alignment was whether the shop would know how to align a Jag. I have been going to this family owned business for years and just a couple of years ago they updated to state of the art modern alignment machines. The guy on the phone said "we have done alignments on BMWs, Mercedes and all kinds of cars, I'm sure we can handle a Jaguar". Is he likely correct?

 

I made a whole research case about aligning my Jag last year, but really, there is nothing much special involved as long as they have reputable equipment and know how to use it.

The aliment settings are in the equipment's computer, and if you want, you can check and bring the settings out of the Jaguar instruction book.



There is one general issue discussed on this forum before, and that is the TOE- IN setting for the fronts.

Perhaps not scientifically proven, but coming from Brutal, a well respected member, they say it is better to use a spreader bar while setting the toe-in.
You can replace the spreader bar by just human force, push the front of the tires out while setting.

This should reduce the infamous tire wear on the inside of the tires.

Finally, camber on the rear can not be set by adjusting, but needs other spacers. You should be within the green if nothing strange happened though.

E.

 

Got the 4 new tires and alignment, but the shop said it was highly unlikely the rear needed any adjustment and said a front end alignment is all I really need.

The front was a little off causing slightly uneven wear which is why a got vibrations when I rotated the tires. He said the rims were very good and the front and rear wheels track perfect together (don't really know the alignment vocabulary, doing the best I can).

The rotors and pads are all new as of a couple of weeks ago. There is a very small vibration sometimes when braking but only on the final slowdown. I suspected maybe the new rotors were not true from the factory (China) and maybe that's the case, but now I have ruled out tires as a cause. It's almost like a pulsing; like the pads are gripping/easing/gripping/easing so I thought maybe the rotors are fine but it's just the ABS system pulsing? I really don't know. It's not bad enough that I feel like taking the new rotors back off and having them turned, but maybe i should?

 

Just as a precaution I would check your hub bearings. I had a very slightly, but still bad, left front just recently and replaced it. That could be your vibration.
Also I had my wheels balanced to try to find a vibration that rolled in around 48 and out at 53 on run up. The standard balance got that vibration out and moved it to 73-77 and it was mad there. I took it back and requested them to road force balance them and now they roll along rather happily all the way to 90.

 

What is the best way to diagnose a hub bearing? If I can't hear them when driving then I generally assume that if the wheel doesn't wiggle when the car is off the ground, that the bearing is fine. I replaced both front hub bearings on my E30 just because of their age (23 years at the time), but they weren't giving symptoms.

I just washed and waxed the car, too. Looking really good!

P.S. -- Interestingly, the vibration does not seem to happen if braking uphill (off ramp to overpass for example).

 

She's looking nice, mine likes a nice coat of McGuires #26 yellow wax, ...she's picky.
To check the hub bearing, get the front wheels off the ground or one at a time. Then (preferably with gloves) grab the bottom of the wheel with one hand at 6 o'clock and put your other palm at the top at 12 and try to move it. Picking up and pushing in. If you get any type of clunking, there's a good chance you have a bad bearing. But it may also be a spindle ball joint. Either way, you shouldn't have any clunking and have located the issue, repeat other side. To check your tie rods use almost the same procedure, but only one wheel off the ground at a time for sure and using the 3 and 9 o'clock positions to check for play. This could also show a bad rack.

 

Is it better to replace the entire hub assembly or just the bearing itself? Is the bearing such a pain to install that buying the assembly is preferable?

 

If it is bad, its cheaper to repress a new bearing vs buying the whole assembly. The bearing is roughly anywhere from $35-65 from after market. I would recommend asking for a Timken which will probably be the $65 one. Then find yourself a machine shop with a 50 ton press to press out the bearing an repress the new one (depending but should cost $50-75 a side). You'll need a speed gear socket to remove it from the back of the spindle.
If you can find the spindle to buy already done, your probably talking around $600+ ea.

 

I have a 12 ton press in my garage, would that be adequate for pressing the bearings out and in?

 

According to specs I read about 10 yrs ago, a 10 ton press was the specified tool. But my guys machine shop said he started with his 20 ton and had to go to the 50 ton. I don't believe the factory compensates for corrosive build up around the rim and seating of the bearing over time.

 

Does it vibrate when braking? If not at what speed does it start to vibrate, and what sped does it stop? Since you have a 308 body, it should be fairly straight forward. If they updated to better equipment, they should have the specs. However you need the rear aligned, which should be done first before aligning the front. If the rear isn't done, then the front won't be right. It's just the toe in the rear that needs to be done, you can adjust camber but it involves removing the axles and installing shims, which is very rarely needed.

As said above in regards to Brutal, he is correct in using a push bar, I used to work with him, he is very knowledgeable, and one of the best techs I've worked with.

As for the bearings go online the 308, the front ones should not have any play, but can still have noise sometimes. The rear bearings should have a little play up and down, but not side to side. My guess is that your vibration is from of the wheels or tires that was one the front and went away after rotating. So don't think you have a bearing problem.

 

I agree with JBzXJ40, my only implication was to check the bearings for the possibility of a bad bearing. Thus why I initially stated about getting the tires road force balanced to be sure as I had to have done.

 

The vibration does not occur at any speed unless the brakes are applied, and honestly, today I could barely feel it at all. I am thinking that the Akebono pads have not been broken in yet and their grip may be improving as I drive the car. According to Akebono, I'm not supposed to conduct a "bed in" procedure but should allow them to bed in naturally over 500 miles or so. I am probably approaching 400 miles since I installed the pads and rotors; plus, my miles are almost all interstate so very little brake use.

I will give them a few hundred more miles before I jump to any conclusions.

 

Ahh, ok well that changes the outcome then. If it vibrates when you brake, then it will be in there then. Usually it's the rotors getting warped. I'm not familiar with that brand of brakes, but maybe follow what they claim for breaking them in. Hopefully it goes away.

 

So the vibration did not disappear...

It did not get worse, but it did not get better. It only happens at medium braking pressure. If I brake lightly or brake hard, no vibration. If I brake medium, there is a pulsing vibration. I would suspect possible wheel bearings but the timing is too perfect; as soon as I replaced the rotors and pads. Too much to be coincidence.

I did not want to accept that brand new rotors could be bad, but perhaps they are.

 

Did you do your own brakes or have someone do them? If someone else did, then head on over there and they will check them for free.

 

I installed the brakes. I guess I'll remove the rotors and take them somewhere to get turned. I hate to shorten the rotor life like that, but I need to be sure. If they are in fact not within spec then I doubt I will buy any more Centric rotors.

Hey highhorse, want to sell your supercharged VDP?