What do you use in your rear axle ???

[jlennon3]

It's time to replace the oil in my rear differential, and I'm thinking about using the Lubrication Engineers Duolec 1605. I contacted the local LE representative and this is the product they recommend for our cars. It's a GL-5 gear oil, SAE 110.

Any opinions or recommendations??? I've heard Redline is also a good product, and I'm certain there are others as well.

I'm kind of leaning toward the Lubrication Engineers product because I've used their Almasol gear oil in the past and it seemed to work well

[awolff280sl]

REDLINE 75W90 GL-5 synthetic gear oil

[Benz Dr.]

Red-Line is good but not localy available to me. I've used Ams/Oil and often use Quaker State or other synthetic gear lubes usually in 80W90 or similar. I can't think of any reason to use a petroleum lube anymore.

My car has a LSD and I had to use an additive along with the synthetic I used. It would growel every time I turned a corner but is now fairly quiet after adding this special stuff. I assume the groweling noise is the clutches slipping inside the diff carrier.

[Bonnyboy]

I use Mercedes Benz Universal Hypoid 85-90 but I have a Limited Slip Diff so the stuff I bought has an additive called Alkenylamine which seems to be common in oils for Limited slip diffs.    The stuff is crazy expensive but is apparently formulated specially for the mercedes limited slip diffs.  Based on my research, if you don't have a LSD, top quality hypoid 75-80w90 is your best bet as recommended by Dr. Benz and awolff280sl above.   I was strongly cautioned about using cheaper noname hypoid oils by a heavy duty mechanic / hot rod guy.

[Benz Dr.]

You have a LSD?  They're more rare than the 5 speed tans option. Not that I'ver seen many 5 speeds but I've only had one car with that option in 35 years. I only know of a couple other examples.