And No, I'm not talking about [email]B@@bs![/email] <img src="/forums/images/graemlins/lol.gif" alt="" />
My 01' xj has Synthetic fluid in the diffs and T-case. $$$$$$
Should I stick with the expensive Synth? Or go back to basic lube?
(Yes, I am askin KIA guys for advice on my Jeep!)
Still a Sporty at Heart! <img src="/forums/images/graemlins/kewl.gif" alt="" />

you don't need synthetic in the diffs.

If it came with synthetic from the factory I would stick with it, but if someone put it in later leave it there, It will last longer then conventional. I changed mine (both diffs,trans, & t-case) to Red Line Synthetic at 100,000 miles and I probably won't change it at 200,000 when it rolls around. I allways ran Dura-blend in the engine and my boy used Max-life once and now it uses a little between changes if I don't use Max-life. I will turn 160,000 next week but with the 31s it will actuly be about 176,000 and still solid as a rock, I couldn't say that about the 2000 ZR2 blazer I had at 30,000 miles and that thier add campain <img src="/forums/images/graemlins/lol.gif" alt="" /> <img src="/forums/images/graemlins/lol.gif" alt="" />.
Dennis

I'm using Redline for all my gear oils in the Sporty. The stuff smelled a bit at first. that soon went away. only noticed quieter gear whine and a little bit easier to find gears when shifting in cold start ups.
I switched it over years ago when the Sporty was my dedicated off-road rig. now that my Freelander has a blown heater core ($$$) my Kia is back to being my daily driver. for the moment I'm treating her gently again. the extra protection of synth probably not needed now.