90 or 140 weight gear oil for the diff.

[4mulas]

Whatcha using for the diff 80/90w or 85/140. I’m using the mopar additive for the suregrip.

Thanks

 

[dadsbee]

80W90

 

[70sixpkrt]

Sta-Lube 85W-90 gear oil GL4

 

[33 IMP]

Where you are, 80w90. Where i am, straight 140.
Edit: two days ago, it was 85f at my house in california. I bet it's not that warm where you are.

 

[4mulas]

Where you are, 80w90. Where i am, straight 140.
Edit: two days ago, it was 85f at my house in california. I bet it's not that warm where you are.

A lot further North. Car only sees spring through fall use. Two days ago here it was 32 degrees. Lol

 

[MoparLeo]

What does your Factory Service Manual tell you to use ?? Or do you want to try something different for a reason ?

 

[451Mopar]

In my 8-3/4" sure grip axle, I used RedLine lightweight shockproof gear oil.
https://www.redlineoil.com/lightweight-shockproof

 

[4mulas]

What does your Factory Service Manual tell you to use ?? Or do you want to try something different for a reason ?

In the back of section three it says “multi-purpose gear lubricant as defined by MIL-L-2105B is used on all rear axles, such a lubricant is available under part no. 2933565, Hypoid Gear Lubricant”

It wasn’t until until reading through the entire section 3 a second time I did find the small blurb with weight recommendation.In high heat or extreme sustained high speed applications I think 140 would be the ticket. However for average day to day 3 season use I think I will stick with 90 weight.

 

[MoparLeo]

The Factory Service Manuals were written to do just what their title says. "Factory Service Manual"
Most answers to questions on these forums are in the Manuals if people would take the time to read them.
A lot of good info on parts And procedures to help explain how to do the servicing.

 

[Johnpat]

No since in using anything more than 90,sure grip additive for posi's

 

[70sixpkrt]

Sta-Lube 85W-90 gear oil GL4

Should be 80-90 GL5 not 4. GL4 is for the transmission. My mistake.

 

[Slap Stick]

There are GL-5s that are for use in transmissions.
I like the "strawberry milkshake" Red Line shock proof heavy in the transmissions and bevels drives of my moorsickles.