What Gear Oil should I buy?
 

I have been running Redline sythetic 75/90w. Is the Mobile 1 syn power good? The local parts store that carried Redline went out of buisness. I could drive into Seattle to buy some if it is better. What weight are you guys running? I want to change the front and rear diffs. and the transfercase this weekend.

Thank you,
Willie

Mobil 1 is good, redline is better. Royal Purple makes good gear oil too. How many miles do you have on the Redline? It should be good for 90,000 miles.

I have 100,000 miles on it. I should have changed it a long time ago.

Willie

I just filled mine up with Mobil One.

80W 90 Lucas, you can see the difference. I ran mobile on in the front and lucas in the rear to test, the rear oil is MILES better over 1 year. I now use all lucas in all three diffs

I have seen references to using the heavier 75w140? as well, do you use it in all the tc , diff, and swivel balls joints or limit it?

Lucas better than mobil 1, that's funny. Lucas is the bastard stepchild of the lubricants family though their synthetic gear oil is OK. Also Mobile is a city in alabama.

I have 75w140 Rotella gear oil in all 3 gear boxes. You can feel the sluggishness in the winter though and I'm sure gas mileage suffers a bit also. Once I'm sure my transfer case is all sealed up I will switch back to Redline in the proper factory recommended weight.

I would agree for engine oil, but for gear oil lucas has never let me down, and resists breakdown better than others in my experience. Lucas climbs the gears better than anything I have ever seen.

Read this and you can pick your own oil!

i use lucas synthetic it works great and quiets the gears a little