Rear-Diff 75W90 VS 75W140

[aksloan]

Going to drain the rear diff this weekend and a friend said I should use the 75W140 instead of the 75W90 even though I don't tow. His logic is that with gears the heavier weight is better and should keep the rear end quieter. The other point he makes is that people only tow a small percentage of the time so most of the time they are running 75W140 under normal driving conditions.... any comments?

 

[jeepkj02]

You'll be okay with the 75w90 if you don't do any towing/hauling or offroading. The 75w140 will protect the gears better when they are under stressful conditions.