MIKEZJ98

I have a 98 5.9 GC with the d44A (aluminum) rear diff, and it has a limited slip, the manual specifies the use of a 75w140 gear oil with the additive, but i could only find 85w140 here in mexico, the stealership charges 50 uds per liter, and the diff uses 2 and a quarter, is really really expensive, could i have troubles if i use this oil?, i intend to put the additive also, and a winns gear oil supplement that supose to make more easy the LS work. thanks. mike

Moparboy01

check out amsoil.com, they have a lot of hd fluids.

whowey

The was multi-viscosity fluids work is this...

At 0 degrees they will be the equivalent of the lower viscosity. But at operating temperatures they will be the equivalent of the higher viscosity number.

So in your case your 85w-140 will behave like an SAE 85 fluid at 0 degrees and an SAE 140 fluid at operating temps. The 75w-140 fluid will behave like an SAE 75 fluid at 0 degrees and an SAE 140 fluid at operating temperatures.

So the first question I ask is how many cold days do you see in Mexico? When I say cold, I mean days approaching 0 degrees. I realize that you may think that 50 or 60 is cold, but not in the this case. If the answer is zero, than the 85w-140 is going to be fine.

LSD additive is a must if you have a limited slip rear end.

But don't bother the Winn's additive... Its not going to do you much good. Spend the money on good fluid in the first place and save yourself the trouble.

MIKEZJ98

we dont see many below 0 degree days just a couple a days a year, maybe a mont or two but the lower i guess will be 5 degrees celcius and a couple i cero, but is not that often, thanks for the answer and everybody is welcome to visit mexico, nad thanks to the owners of the forum and everybody hows involved for the space and the answers