I'm getting my truck ready to pull my new 5th wheel trailer. It will weigh around 16k lbs. when loaded. I am down to figuring out what brand and viscosity of rear axle synthetic lubricant to use. 1996 Dodge - 2500 - Dana 70 - 4.10:1 - Cummins. Any opinions on brand and viscosity are welcomed.

Thanks!

 

IMO, since it's easy to get Mobil 1 75w-140. I tow, but not as heavy as you, and experience cold weather, so I run Mobil 1 75w-90. Might have a little trouble with getting the 75-140 (so I have heard) but autozone carries the 75-90 for sure.

Don't forget to get additive for the clutch plates (if you have posi-do a search for lube gaurd), and fill to 3/8 ths of an inch BELOW the fill plug. I used the additive that autozone carries with no problems.

 

Thanks. I have access to 75-140 Redline through my distributor and the local stores have 75-90 and other synthetics.