D30 gear oil.

[TapouT]

I purchased a 1997 Jeep Cherokee 4x4 recently for a steal of a deal. I've been driving it daily for a month now and have noticed since day one it's had a slight grinding/soft metal noise in the front end. Put a set of brakes on it because it needed it and still heard the noise so I cracked the fill hole on the front diff and there was metal on the drain plug/oil coming out. I'm going to change the gear oil in it and keep driving it. It's really not that loud at all and with the radio up I can barely hear it LOL what gear oil do you guys use/recommend and what weight? I see that the owners manual calls for 75w90. Would it hurt to switch to synthetic 75w140 since the ring and pinion has experienced some wear? I'm probably going to change the gear oil in the Chrysler 8.25 in the rear also at the same time. If nothing else, I'll put another D30 in it when/if this one blows apart.

 

[Tom@Hilltop_Machine]

75-90 should be fine if there is no locker in it.

 

[rodney eppes]

Yea like tknopp said, just some regular 75-90. Sounds like it's too late to waste any money on the good lubes. Pull that cover & see what's going on, & Best way to clean it out. I'd be pulling the rear cover too, & check it out. Never know if it's had water in it or other damage! Wont cost much to find out for sure!

 

[PAT Ventures]

Gear Oil - Heat, Break in, Frequency, synthetic, dyno, brand?