Gear oil for the 8.8 & D35?

[Iron Weasel]

Alldata specifies 90 Hypoid Gear Oil for the front & rear differentials. Did some "Googling" for more specific information and found plenty of conflicting information.

Some of the highlights.

• Synthetic is required.
• Convential is OK.
• 75W90 is OK.
• 85W140 is required per a Ford TSB.

So yeah....it's a '94 4x4 with open 3.73's and 31" BFG AT's. It's on pavement 85% of the time and no towing of any kind.

What do I go with?

 

[techieman33]

85w90 for open diffs, 75w140 for the rear if it's limited slip.

 

[Iron Weasel]

Good deal, I'll see what I can find.

If I can't come across any 85W90, would 75W90 be OK? Rather have the info before I go out and get some so I'm not going out twice.