Hi guys. The differential in my 2000 XJR ate itself at 93k, so I bought one from Ebay that was supposed to be from an '02 XJ8 with 67k (having learned from here that the X308 V8 ones are all the same). I dropped the whole rear end assembly, took the old diff out, but when I tried to put the new one back in I found that the two pins in the back at the bottom are larger diameter than the old ones. (pic attached) So they wouldn't fit through the holes in that bottom pan piece, and sure weren't going to fit through the bushings in the crossmember.

No problem, I thought, the pins have hex flats on them, I'll just swap them out. I didn't have a wrench that big (they're bigger than 7/8; anyone know the size?), and a cheapy 12" crescent wrench wouldn't budge them. I tried an 18" pipewrench on one with no luck either.

I've sprayed them down with PB Blaster and will try again tomorrow, but has anyone ever tried to remove those? I've got a little propane torch to try as a next resort, as well as buy the right size box-end wrench. The diffs look exactly the same and have the same part numbers, and the front/upper pins are the same diameter. Was there maybe a design change along the way that went to bigger pins?

Thanks for any help you can provide.
Mike

 

Yea you're gonna have to take some heat to them for them to come out... just swap them and it should work.

 

Your car's VIN is before 846051 and the bolts are bigger diameter. I have the same issue , fitting a rear link from an early Sport model (to put the rear sway bar on my non-Sport version).

 

If those pins have red loctite or equivalent on the threads, the instructions on the package say that heat must be applied if the threads are to be unlocked. The red is supposed to be for permanent threads. Unfortunately, you have to apply the heat to the casing because if you apply heat to the pin, it will make them expand which is not good(TM)

 

Thanks for the info, guys. Heat it is.

 

Careful. Differential lubricant is still a petroleum product. Might want to use a heat gun as opposed to open flame. Or open, drain and clean first.

 

Go with this advice as a no brainer.

And change the breather tube while it's out of the car, along with about 2lt of Shell EP90 diff oil. the tube is a $15 and insures against leaks.

You can see what the old stuff is like and how it smells is a good indication of how it's been treated. Cooked diff oil has a distinctive foul smell!