75W - 140 Synthetic Gear Lube

[Roy W]

I mistakenly bought 75W - 140 Mobil 1 synthetic gear lube for the 5000 mile rear differential gear lube change. Can I use this, or should I return it and get the correct 75W - 90 weight? I live in Florida, but am planning a 8000 mile trip to the northwest next summer pulling a 9200 lb travel trailer.

[Inspector]

I would think that it wouldn't hurt to use the 75-140. I use it in my duelly but I do tow heavy. There may be opinions to the contrary because you do tow a light trailer and those folks will pipe in.
Denny ;)

[Tractor]

Roy W
My crew chief [my son T.J.] and myself thought about that call for some time. We checked with our top notch mechanic friend, to find out what he was putting in the diesel trucks that were pulling loads. when all was said and done our dually diesel has 75W-140 synthenic oil in the rear end just like the INSPECTOR has in his. We changed fluids before we went to Salt Lake. We all have our opinion, that is mine.
TRACTOR