I am in the process of a driveline overhaul, partly to eliminate the cold weather whine the X Types are known for. At the moment I have the transfer case and driveshaft out of the car and while I have easy access I checked the freeplay of the rear differential pinion hub. It moves way more than a typical differential should, so to me that says the backlash is out of spec.I also have a whine on smooth pavement that comes and goes as power is applied or removed at constant speed, another indicator of a diff out of spec.

Is there a manual or instructions for rebuilding the differential? I see that Jaguar does not sell any internal parts, just a whole unit exchange. I've rebuilt an XJS differential before, so have the tools to do it, but specs and clearances would be useful.

 

its not worth rebuilding ,if you open your diff you will find sludge , when it gets cold it takes a while for the oil to get warm , ive got the sludge out of mine and put royal purple in ,whine gone

 

I have changed the oil - made no difference.

 

they are so cheap you can get one in ct for $70 when i put royal purple in mine noise instantly stoped for the lassst 6 winters, but your issue maybe differant

 

It sounds more like a carrier bearing problem = i.e. "the cold weather whine X's are known for".

 

I have two different noises. I have the typical cold weather whine, plus a much more subtle whine. The cold weather noise is speed dependant, and generally doesn't happen when the temperature is above freezing. It's right at 40 km/h and 70 km/h. The more subtle noise occurs at any temperature and roadspeed and I can make it come and go with application of throttle at a constant speed.

All the other Jaguar differentials I have from XJ's have an almost imperceptible amount of movement when I turn the pinion shaft before the output shafts move. Essentially zero slop in the gears. When I have the driveshaft out of the X Type tonight I could turn the pinion about 1/8" at the hub with no movement of the output shafts. I could also hear a clunk as I moved the pinion back and forth when it contacted the teeth of the crown wheel I'm assuming. To me it feels like excessive backlash. The transfer case is essentially a differential, and it is like the XJ differentials in terms of backlash - essentially no slop in the gear mesh.