anyone been using either of the two for a LONG time now? anything good or bad about them?

 

I assume you are speaking of the front and rear diff's. I Put Mobil 1 in mine at 2500, 15000, and again at 30,000 miles. I am currently at 39000 miles with no issues.

 

Used it once and I will not use it again. I use Amsoil sever gear oil in my last 2 truck and have it in this one. Personally I wouldn’t use any thing else in my trucks diff.

 

what wont you use again and why.

 

I changed out my diffs at 15,000 (factory stuff was nasty). Then again at 30,000 and 50,000 miles.....and have used Mobil 1 75w90 all 3 times in both diffs. Very good stuff. Looked like new when it came back out. I have had zero problems with it.

 

looks like im going w/ the mobil1

i have always had good luck w/ their synthetic 10w30 in my race motors, now its time to give their gear lube a try.

i have never tried lucas products before, and i have heard both good and bad things about them. dont think i want to find out for myself.

thanks guys.

 

i've used nothing but mobil 1 for years ... never had any problems

i would never use amsoil ...

 

I have used Lucas for 19 years now and have never had any issues, both in the diff's, tranny, oil, and fuel. Some wont use it, claiming high foam/air bubbles, but I have never had a problem.

 

Well I had the rear end rebuilt in my 85 Ford F150 and used M1 and 3K later I had a noise so I check the oil level and what I found was the level was OK but the oil was black and smelled burnt. Pull the cover and my gears were burned up so I had to spend more money to replace the rear end. So the second time I took the advice of a trucker friend who had suggested that I use Amsoil severe gear oil the first time I had it built. I wish I had listened but I used M1 because it was cheaper and I thought it should be just as good. Well I decided to use the Amsoil in the 2nd rebuild and until the day I sold the truck I never had another problem with the rear end nor did I ever have the gear oil turn black.