Changing front wheel bearing 96 XK8

[rogerpalin]

I am about to fit a new front wheel bearing, but have conflicting figures on the tightening torque for the abs/rotor nut. Original jag manual (96) gives 150-170 Nm, but Nigel Thorley's book suggests 220 Nm. Alldata suggest 270 - 330! Since it is probably necessary to tighten past these figures to get the spring pins to engage, any advice on the correct figure would be much appreciated.

[Nik]

Hi Rodger ,
Refit the ABS nut and, using the special socket (part number JD 228) tighten to 150 - 190Nm ,
then identify the next two sets of holes and lug gaps to line up , and continue tightening until the locking pins slide easily into position ,

Hope this helps ,

Nik

PS Don't forget to align both of the wheel bearing retaining circlips with their gaps at the lowest point (allowing for the castor angle when fitted) as this is often the cause of bearing failure as any water that gets in can't drain out

[rogerpalin]

Hi Nik,

thanks for the info. The bearing was actually changed about 30k miles ago before I got the car, so it will be interesting to see if circlips are correctly fitted. Other side has apparently never been done in 130k!

As soon as I can get the tool from JEC parts I'll crack on with the job.

Roger

[Nik]

Hi Rodger ,

Best of luck with the job ,

Nik

[mike020150]

Out of interest, I've checked the current Jaguar service info for tightening the rotor nut. The torque figure is given as 270-330nm, otherwise known as damned tight! As Nik says, start with a slightly lower figure to allow for aligning the holes. The torque range is the same for early and late cars. Mike.

[rogerpalin]

Have just road tested the car after changing bearing. Not actually sorry I started but it was a close thing! A few observations for anybody else thinking of doing it themselves.

There are a lot of special tools listed, mostly for the press, but the only ones I found essential were a hydraulic press, the JD228 rotor nut socket and a ball joint splitter. You also need at least a 3/4 inch tommy bar, and I used 3/4 inch sockets for a lot of press jobs. I ordered a set of Sealey heavy duty circlip pliers, but they got lost in a postal strike and arrived just as I was about to fit the last circlip the hard way.

Well worth reading the Nigel Thorley book on this job, he highlights the two major problems. The lower wishbone ball joint needed the assistance of a 4 lb lump hammer to shift it (don't have oxy acetylene so don't know if heat would help) and despite being built like a BBSH I had to use a seven foot scaffold pole to remove the rotor nut. I didn't have the special tool to clamp the rotor, but found a perfect substitute in my boot. The temporary spare wheel! Bolt on the rotor using 5/8 Whitworth nuts as spacers, then bolt down to bench using 1/2 inch bolts. Worked v well.

When removing the rotor nut the tool jumps off the nut when you build up any useful torque, so I clamped a piece of angle iron over the tommy bar onto the hub carrier.

Once the hub nut is loose the rest of the job is a doddle. Pressing out the rotor without the adaptor is an interesting challenge, but judicious placement of engineering bricks on the press bed (remembering they are only strong in compression!) got the job done. The bearing can be pressed out with a 41 mm socket.

Re-fitting is a breeze. The old bearing is wrecked when you press out the rotor, and if you remove half the inner shell you have the perfect special tool to fit the new one. The bore of the hub carrier above the bearing seat is slightly larger than the bearing diameter allowing you to do this. This was probably an oversight on the part of jaguar so best to check on your own vehicle before proceeding!

To fit the rotor you need to support the inner bearing shell, and again the 41mm socket is the perfect length. I taped a few layers of cardboard to the outside of the socket to hold it concentrically in the hub carrier.

Once I refitted the circlip to point DOWN (thanks Nik) it was a simple matter to redo the rotor nut which compared with undoing is only finger tight. Didn't want to buy a 3/4 torque wrench, but set the torque by attaching a 750mm bar to the tommy bar and then pulling on the end via a digital spring balance until I had about 20 - 22 Kg indicated.

After that all straightforward.