gear oil

[ironman]

what gear oil do we use in a 8.8 rearend with 373 gears dont know if that matters but just thought id add that info just in case and does it take about 2 quarts to fill it up.

 

[metalmacguyver]

gear ratio doesnt matter. most people use standard GL5 80w-90 gear oil. if you have a L/S, your supposed to add friction modifier. i dont. friction modifier is meant to help the L/S slip more. i want it to grab more.

 

[MAKG]

And you can skip the friction modifier if you don't have a limited slip chattering problem (a very likely situation if you use a synthetic GL-5 hypoid gear oil).

 

[AllanD]

And if you want the limited slip to be more positive you can skip the friction modifier as well.

Chattering is only an annoying noise that tells you your limited slip is working.

And for the record in my 4.10 geared limited slip axle I run the Ford 80w-140synthetic.

If you run this oil be SURE to wash ALL of any other oil out of the housing and tubes.

The 80w-140 turns into "pudding" if mixed with conventional oils.
I don't know why.

AD

 

[ironman]

what about royal purple gear oil 75w95 i am going with 373 gearsand limited slip diff. will this oil work.

 

[Hahnsb2]

Yes, however I prefer AMSOIL over RP, it's better oil and its a bit cheaper if you can find it.

 

[ironman]

thanks for the info guys

 

[MAKG]

Yes, however I prefer AMSOIL over RP, it's better oil and its a bit cheaper if you can find it.

And either is equivalent to shredding a few $20 bills in conventional gear oil.

Use the correct API and SAE ratings, and you're good to go. Synthetic gear oil is not any better than conventional gear oil. It's not the same as for crankcases; gearboxes are much friendlier environments.

I only use synthetic (and then the cheapest I can find -- usually Mobil 1) because I hate the smell of conventional gear oil. The truck couldn't care less.

 

[Hahnsb2]

I used AMSOIL becuase of my lock-right, I wanted to make it last as long as possible since it was used when I got it. I'm sure it will deffinatly help with wear of the locker, besides, it's only money... I think it was under $10 a quart...

 

[kunar]

And either is equivalent to shredding a few $20 bills in conventional gear oil.

so youre saying if i just leave a crisp $20 inside next time i have the cover off, then fill up with conventional?

 

[Sasquatch_Ryda]

And if you want the limited slip to be more positive you can skip the friction modifier as well.

Chattering is only an annoying noise that tells you your limited slip is working.

And for the record in my 4.10 geared limited slip axle I run the Ford 80w-140synthetic.

If you run this oil be SURE to wash ALL of any other oil out of the housing and tubes.

The 80w-140 turns into "pudding" if mixed with conventional oils.
I don't know why.

AD

You mean motorcraft 75w140 right? I have never seen an 80w140 at work yet