Manual Transmission & Differentials

[River6822@aol.com]

I have an 88 80q with 118,000 miles. I have a clunking noise when shifting 
hard. It sounds exactly like worn rear differential mounts/bushings. I 
changed them last week and the sound, although slightly better, is not much 
different. What else could it be ?

How do I change the transmission fluid/oil and the rear differential 
fluid/oil ?

I have a Bentley but I can't find the procedure. Could some one point me in 
the right direction.

Scott Calabrese