GL 5 Fluid For Differential

[MJWenrich]

I need to service the differentials on my 4 wheel drive, 2004.5 2500 and I have some Sta Lube 85-140 GL 5 limited slip gear oil and I believe my truck calls for SYN 75-90 GL5. Is the 85-140 too heavy? I live in a Ca. climate that rarely dips below 20 degrees and is usually 40-100 degrees. I was thinking maybe the lighter weight is for the far north. Appreciate the advice. I have no problem buying the right stuff but hate to add yet another bottle of lube if I don't need to. Would appreciate advice.

Mike

 

[jhenderson]

If the Sta Lube is syn I wouldn't be afraid to blend it with some 75-90. Probably up to 50%.

 

[BDaugherty]

My truck is used mostly for short trips and doesn't pull heavy very often. I use 75w90 synthetic. If i drove a lot of longer trips or pulled heavier loads frequently, i would feel better with the heavier oil.

 

[amsoilman]

The 85W-140 is to Viscous for your truck, and will actually make the Differentials run hotter because it is to thick. A HIGH QUALITY synthetic 75W-90 GL-5 fluid will protect as well as keep the Differentials cooler running. This has been proven time and again over the years.

 

[BLNRAY]

396,750 mi on 75w-90 mobil 1 synthetic change every 50,000,i dont see any advantage to running anything else.most of those miles are towing,sometimes pretty heavy

 

[Prairie Dog]

396,750 mi on 75w-90 mobil 1 synthetic change every 50,000,i dont see any advantage to running anything else.most of those miles are towing,sometimes pretty heavy

I've had similar experiences with my trucks. Mobile 1 is good stuff.