Thanks for all the help all the time, Motorcarman. So, I cleaned my breather, etc., and didn't clean the underside of the diff, but it's no longer spotting the garage floor. BUT the After on the car still looks like the Before. Does the diff blow enough oil that it gets onto the mufflers and coat the crossmember? No idea where else motor oil could be coming from back there...?

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`00 XJR Titanium Pearl Metallic Oooooooo...

 

Strange....most of the postings in this thread are over 10 years old.

 

Diagnosing a leak from my pinion and output seal and upon recommendation, I'm starting with the breather. I removed/cleaned it. Testing yielded I needed to blow fairly hard before it opened. I suspect there should be little, if any resistance, correct?

Is there a way to repair? If not, where might I find a new one? Jaguar parts do not list the part number I found above (JLM20323) or any keyword for differential breather. Other parts sites, same result.