Well, I have the dreaded differential whine on my 2003 XJR with 71k miles. After doing some reading, I thought there was a good bet that it would be the output shaft bearings so I sourced a used differential from an XK with 48k miles for less than what it would cost to get one bearing, lol. I knew that the output shafts were the same so I swapped the ones from the XK with mine. No change in the noise whatsoever.

So, since the noise is definitely coming from the differential, it has to be internal. I am lucky enough to have a big shop near me that specializes in differentials and they have done 14hu's before. So, I can take the differential to them for a refresh if I supply the parts. The internal bearings, crush sleeve, seal, etc. are all on order.

To save me some time, it occurred to me that I could give them the XK differential for the rebuild while I spend the hours it will take to remove mine, lol. HOWEVER, I seem to recall in another thread that there are differences between the two differentials but I can't remember the specifics.

I can clearly see that the pinion flanges are different but my question is whether the internals the same or different?

Thanks in advance!
Ben

 

Pinion flanges are different. The ratio needs to be considered as well.

 

Thanks, Bob!