cbrose

At some point, when the east coast weather gets a bit warmer, I'll do my tranny and transfer case. The repair manual suggests API G4/G5 in the SAE 80W-90W range. Seeing that it rarely gets below 0 degrees in the Philly suburbs, 90W hypoid gear oil is the requirement. However, I have a bottle of Valvoline synthetic 75W-90W gear oil in my garage (http://www.valvoline.com/products/br...er/gear-oil/59). Would this be OK to use? Does the weight range matter in this case? Would this oil be too thin? Thanks!

cbrose

After some reading/searching, I found some comments from people asking the same question with their vehicles. Here's a response from Mobile 1 on using 75w90 where 80w90 or 90w is called for:
http://www.mobiloil.com/USA-English/...Viscosity.aspx

Could be propaganda from Mobil 1, but makes sense it's still 90w at operating temperature and it meets the GL-5 EP rating. Comments?

JPSMAN

I have used the Mobil 1 product before, as long as it meets the API GL5 its fine....that is the standard that is required etc.