Hello: New maintenance project. Quick question.
1: My truck is 1997 Ford F-150 regular cab, 4.2L V6 2WD
2: Project Description: Changing Differential fluid
3: Question: I have about 3 bottles of Amsoil 80W90 oil. Is it OK to used it in the standard 8.8 differential? My differential is not limited slip.

thanks in advance

 

I think 75-140 fluid is what you'd need. An owners manual will say what is needed for sure. Other than that, either get a diff cover gasket or if using silicone, apply the bead and let it sit for a while, like overnight. If you apply the silicone and immediately install cover, 50/50 chance it will leak within a day!!!

 

Yes it is 75w-140 synthetic gear lube for the rear. You also want to add a friction modifier when changing lubricant

 

You dont need friction modifier if you have an open differential. You only need it if you have a letter in your axle code that means its limited slip.

 

that doesent matter. adding 4oz of friction modifier when changing the diff fluid should be used. im not saying it has to be. im sure no one does but it is the right way to do it.

 

you do not need friction modifier!!

 

yes you most certainly do. Now does anyone do it? Probably not. Id also like to add if you dont want to replace your diff cover gasket and its not leaking. you can drain the fluid out with a suction pump through the filler hole.

 

NO YOU DONT! he doesnt have a LS differential!

 

Well you would do it wrong anyway since you cant even drive and obey the speed limit right.

 

You sure are hard headed.

He doesn't need the FM because he doesn't have a LS. Why is that hard for you to understand?

 

Yes, please explain why you would need friction modifier if you dont have friction/clutch plates (ls)

 

OK then i have been mistaken. Only need it for limited slip.

Op.. im gonna be changing mine to and found that advanced auto has the 75w-140 fluid not sure if you have one of those around you. But i couldent find any at auto zone.

 

Clutch plates are not found in the differential case.

 

lulz, yes they are. if you have a LS diff.


what would you like to call them then?

 

I agree, you do not need friction modifier if you do not have a limited slip. It is an additive made for this specifically. Read the bottles of axle fluids, many say they've got it already in for today's limited slip diffs, but put a bottle in anyways. This tool guy likes to argue so pay no attention.