2001 5.4l 4X4: I know what Ford recommends for rear end and transaxle fluids, (75-90W and 75-140W) but what say you guys?

Can I use 75-90W Synthetic in the transaxle?

Thanks,

Jim

 

As the book says. No reason to do anything else. Amsoil Severe Gear!

Transfer case calls for ATF...DO NOT put gear oil in it. Amsoil ATF in the transfer case and tranny!

 

Not transfer case; meant front differential.

Jim

 

I use 75-140 fully synthetic. I used it in both the front and rear. The last time I got it at O'rielleys for about 10 bucks a quart and it has friction modifier in it. Dont recall what brand it was..

 

Ford backward spec'd 75W140 for the front and the rear to save on the cost of using two separate weight oils for no reason. 75W140 will work just fine in the front, but I still use 75W90 in the front.

 

I find it hard to go wrong using the Ford recommended gear oil from the dealer. It is a pure synthetic and is about the same price as aftermarket. Last I changed my rear diff it was about $75 for 3 quarts and friction modifier. As a lifelong technician and automotive instructor I have never had a problem when using OEM parts and fluids.

 

I agree shop. Is the friction stuff a separate bottle? That's what locking differential needs, right?

 

The limited slip diff needs additional friction modifier. Ford sells it in 4 oz bottles, you would need one.

 

Just dont spill this modifier on you. It smells pretty rancid and lingers for awhile on your hands if you do. Wear some rubber gloves/exam gloves if you have them.

 

Thats why they call it skunk fluid.