hi my jeep iscj7 1983 258cdi with t4 manualtransmission i always use SAE 80W90 gearoil forlongtime but i haveseen chilton's automotivebook they side t4-t5 transimssion use Dexron 2 ???so ihave to changefiuld ?? thankyou. <img src="/forums/images/graemlins/confused.gif" alt="" /> <img src="/forums/images/graemlins/frown.gif" alt="" />

With a tranny that old I would NOT change fluids. Just keep on using what it ever you have been putting in there.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

I'd always used gear oil and didn't even think of using Dextron in my transfer case, but noticed an annoying leak at the output shaft that was causing WAY premature drying of the ujoints and had to replace them every thousand miles or so even if I regreased them daily. transfer case was new enough to swap over to using Dextron as it calls for, flushed it using Dextron for about 5 cycles till there was no more grease noticable in the draining, and have run Dextron since, and no leaks and ujoints are lasting about 10+ months or so now. If everything is functioning normally and you don't have any side affects of using the gear oil that you have been using all along, stick with it. If it ain't broke, don't fix it!

i have been using 80-90 in my T176 and recently switch to sythetic 80-90 bc it wouldnt shift in/out good when it was cold. it has made a big difference the synthetic is amazing, worth the money. i would put it in engine but it would just come right back out!!!