differential gear oil
 

i have a 1985 seville 4.1 motor front wheel drive what type of oil to put in the differential thanks

Oil
 

Use SAE 80 or SAE80-90 GL5 Gear Lube Some GM#1052271 or 1052272. Recommended change every 10,000 and check level once a year.

Why so often? Just because it's front-wheel drive and runs hotter? For rear differentials changing the oil every 100K miles is usually more than often enough.

Diff. Oil
 

Just from the GM maintenance charts, not something that I recommend. I agree that it is too often as well and never do it more often than about 50,000. All depends if you have been towing or not.