Brucie’s Diary: August 2012

Current mileage: 141,773

Jaguar X300 Rear differential service – carried out in April 2012

The next job on my list was to have the rear diff serviced, as it had been leaking oil since I purchased Brucie in Nov 2010 and I hadn’t got as far as having the work done until April 2012.

I was told by a main dealer that Brucie would need a new rear diff. I went away to mull this over, and see how much a new or used rear diff would cost. On thinking about it further, I decided that I wouldn’t want to risk buying a used rear diff, as it might be a whiner! Then I asked myself “why would Brucie need a new rear diff when his didn’t whine?” Surely it only needed the seals renewing in order to stop the oil leakage? I did a bit of independent research and my theory was confirmed, so I returned to the Main Dealer and pointed this out, stating that I was not prepared to swap my cars rear diff for an equivalent used one, and if a new one were purchased, as far as I was aware it would still need assembling, as they arrive minus their seals and outputs shafts anyway, so why not just order the seals and change those? This was, in fact, what was done in due course, so now Brucie does not leak oil from his rear diff anymore!

The work was carried out by a Jaguar Main Dealer and unfortunately I was unable to get any pictures of the work in progress.

Parts used included:



Number on diagram Description Part Number
11 Output shaft oil seal (x2) JLM12138
12 Diff bearing retaining plate (1) JLM20181
13 Torx head bolt (x5) JLM12139
15 Diff output (ball) bearing (x2) JLM11527
16 Shaft bearing retaining collar (x2) JLM615



Although I can find no invoice for the drive shaft shim kit or O ring, I am sure these would also have been replaced.

Please refer to the diagram and full parts list below, provided by Jaguar Heritage Parts


1 Pinion locknut
2 Collapsible spacer
3 Pinion bearing
4 Taper roller bearing
5 Xylan coated washer
6 Pinion oil seal
7 Companion flange
8 Pinion head shim kit
9 Drive shaft
10 Stud
11 Output shaft oil seal
12 Retaining plate
13 Torx head bolt
14 O-ring
15 Ball bearing
16 Shaft bearing retain’g collar
17 Drive shaft shim kit
18 Nut
19 Roller bearing
20 Differential bearing shim kit
21 Differential
22 Crownwheel and pinion
23 Drive gear bolt