I had my rear end completly replaced on my 01 F-150 Crew Cab with 62000 miles on it. The specks say to use a 75-140 Syn gear lub wich they did Valveoline VV 982 lube. This afternoon I had a mech. tell me that he used to work at a Ford Dealership and that they had some problems with the 00 & 01 rear ends useing the syn lube and they had went back to the 90W gear lube without any problems. Has anyone heard of this takeing place? The rear end was a 355 if that's any help. Thanks for any help or insite you might give.

 

I havent heard of problems with the Sterling/Ford differentials, but it is possible. I had a 93 GM 8.875 that started seeping from the pinion seal as soon as I changed to syn, but it had dino as factory fill. Toyota uses dino in limited slip units, but syn in the open ones.

Jim

 

I had the rear end open on my '05 a few months, (about 10,000 miles) back.
Same rear end as your truck.
I used a house brand from a local inependent shop.
Something or other Synthetic 75-140. It seems to be working perfectly.
Assuming you have an open diff, I suspect you'll be fine.

The guy you talked to mentioned "problems". Did he elaborate?
Leaking?
Nosie?
Bearing failure?
Gear wear?

Thanks.

 

He mentioned about noise and gear wear. On mine, the diff bearings were starting to pit, plus the gears were wearing, and the reason I noticed it was it seemed to be making quite a bit of noise (howling) from what sounded like the back end. After I replaced everything brand new (Ford) which was under extended warranty I can't hear any noise what so ever. The thing is if it calls for syn. lube thats what I would like to use. Just wondering if anyone else had heard of that type of problem.