I noticed that my 1987 is starting to leak a small bit of oil from the transmission. I have two questions:
1. How much oil can I lose from the transmission before I need to worry about it?
2. If I were to pull the transmission and fix the gasket, is there anything else I should replace at the same time like clutch, brakes, tub seal, etc...? Is it worth my time to replace anything in the working transmission as preventative maintenance?
Post# 437075 , Reply# 1   5/23/2010 at 23:57 (5,076 days old) by cfz2882(Belle Fourche,SD)  
would be good to check the coupler-it was a weakness with the
early DDs and has been improved several times since 1987-
from what i've heard too much lash in the coupler can cause
malfunction of the neutral drain feature.Also could check the
clutch pads.I haven't had a DD tranny apart for a while,so not
sure how much oil can be lost without trouble but i would
guess quite a bit.
I wouldn't bother breaking open the transmission. They are so easy to replace. Maybe John or Jason can shed better light on intra-transmission service.