Rear Diff Fluid Recommendation

[mjmendoza]

i am just wondering what the best gear fluid would be to put in the rear diff. from what i was told 80w-90 is the right fluid but i want to know what you guys put in your rear diffs.

 

[jdub]

Do you have an LSD?

 

[AJ'S 88NA]

i am just wondering what the best gear fluid would be to put in the rear diff. from what i was told 80w-90 is the right fluid but i want to know what you guys put in your rear diffs.

Check out the Oil and Lube section on the main page, all you need to know about it in there, brought to you by none other than Jdub

 

[Island_Yota]

Im wondering this aswell, checked the Lubrication/Oil forum and didn't find much info. My LSD is starting to make the chatter sound, want to change it asap along with the transmission fluid, from what ive read Redline Mt90 is the way to go for the W58 but im still not decided for the rear end.. Ive heard Ford 80w-90 with a few Oz's of Ford LSD additive works good for higher mileage cars?

 

[jdub]

The Ford LSD oil is a 75W-90 and you will need the LSD additive. On high mileage differentials, I think it's a better choice.

 

[black91turbo]

question answered by jdub's last post, sorry

 

[black91turbo]

The LSD only takes 1.4floz according to the TSRM, what is this additive and how much should be added?

 

[jdub]

It's Ford friction modifier...it allows an LSD to "slip" for proper operation. I would start with one oz.

Red Line 75W-90 is another good choice and it has the friction modifier already in it. On a high mileage LSD, you may get clatter with Red Line.

 

[IJ.]

Very different oil to the "front diff" .... :nono:

 

[grimreaper]

It's Ford friction modifier...it allows an LSD to "slip" for proper operation. I would start with one oz.

Red Line 75W-90 is another good choice and it has the friction modifier already in it. On a high mileage LSD, you may get clatter with Red Line.

what would you consider "high" mileage? low mileage on these now a days is what, 90,000 miles?

 

[jdub]

If you put Red Line in it and it clatters, it's high mileage

Seriously though, a better phrase is "well worn" and that is a judgement call. If it's seen abuse (autocross, burn outs, etc) or if the oil was never changed, it's probably worn. Under normal city/highway driving and periodic oil changes, I would consider the 150K point as "high mileage".

 

[grimreaper]

If you put Red Line in it and it clatters, it's high mileage

:yelrotflm

 

[jdub]

be sure not to use any fluid with friction modifiers.

You bumped a 2 1/2 yr old thread to say BS like that? A LSD requires friction modifiers - a std differential does not, but friction modifiers will not hurt it or make a difference. A manual tranny is a different story.