Hey there,

while I'm giving my suspension a thorough workover, I've come accross the differences in wheel bearings due to different hubs. I am aware of the difference in hubs or better said in the uprights/vertical connections. But were they better?

Reason I am asking is simple: I always keep on experiencing warped discs/rotors. The discs though aren't warped but they act like it. So my guess is the bearings are toast which I would put down to the old style smaller bearings just not being as durable as they could be...

Is it worth upgrading to the larger wheel bearing hubs? I'm going 325 mm brakes in the front and also need wheel bearings and will be having the entire axle apart...

Cheers

Damien

 

You post doesn't tell us what you are working on, but I encountered the same problem on my XK8 1997 when doing the front wheel bearing. The larger bearing came on the updated hub. The problem is on early models the left and right hubs are identical and on the later model the hubs are specific to each side. They also changed the mounting points and changed the location of the caliper mount.
As such I had to stay with the hub I had and replace the bearing in lieu of replacing the vertical mount. The earlier used the smaller diameter wheel bearing. The difference in size is so small I don't think it makes one better than the other.

 

The 1999MY onward use the Vertical Links with the larger 80mm bearing.
The early cars used 76mm bearings.

You can swap the later Vertical Links if you can find some in a salvage yard.

bob

 

Erm, I posted in the X308 section... So I would guess I am working on an XJ The upright is interchangable. Okay, I wasn't aware of the difference in the hub itself...

Should be no worry but is it worth it? The bearings are larger, so I assume they didn't make them larger for no reason... There must be some kind of technical reason (bearing wear, stability, wobbles, ...)... Do you know of anything there, Bob?

Cheers

Damien

 

Is it possible that you have uneven brake pad deposition on the discs? If you've measured the discs to ensure that they aren't physically warped, but they still behave as if they're warped (judder or pulsation during braking), you might have slightly more brake pad material transferred onto only certain parts of the disc, causing the pulsation.

Bedding In Brake Rotors

 

The judder only comes in after a longer periodisch of driving. The longer the worse. Measured with a very fine gauge ans there is no wobble or warping noticeable - when cold.

Discs and pads were always driven/bedded in. It has happend on several different pads and discs.

Calipers work both perfectly. No binding or sticking...

 

I have replaced dozens of 76mm bearings but very few 80mm bearings. I guess the larger bearings are what the car needed from the start????

bob

 

That sounds quite what I had in mind... Larger bearings normally last longer.

Thanks Bob!