In a 2001 wrangler TJ 5 speed manual 4.0liter 6cylinder what gear oil are poeple running in their tranny's, i am currently using mopar 75-90w synthetic i believe. I have heard good things about redline products perhaps a different oil...same weight, but i would think that gear oil's would not change much just different additives. perhaps a different wieght? something to smooth out the shifting.

You need to use the mopar oil in the 2000+ 5 speed NV3550 to still be in warranty(did you buy it used recently? If not, disregard that). I'd just use 75W-90 Synchromesh oil if you don't worry about warranty.

thank you for the reply... my jeep is used and i currently have around 94,000 miles on the jeep, i bought with about 89 thousand miles, perfect shape all highway useage. so warranty is not a issue i'm well out of any powertrain warranty.. Redline recommended MTL 70W-80 synthetic oil, i think that the gears are just not slowing down quick enough to allow for everything to lign up properly.. redline also offers a MT-90 which is a 75W-90 synthetic if i should stay with the recommended weight.