Helping a Chevy Dana 60s rear axle survive

[booster]

The discussion about the temperature rise with Agilis tires brought up the topic of the Dana 60s semifloating rear axles putting heat into the rear wheels and tires, especially when you have the non OEM offset aluminum wheels that put more stress on the axle bearings.


Obviously, getting the factory offset wheels would help a lot, but beyond that there may be other stuff that might help. This is based on what the pickup truck people do for both the semi floating axles like the Dana 60s and the bigger full floating axles like the Dana 70s that is also used in the Chevies with the towing package.


IMO, getting the very best gear oil you can find is a good idea. I think most if not all of the Dana axles in the vans came with the GM purple synthetic gear oil, which isn't bad stuff, but for what it costs you may do better with others. For these axles, limited slip additive is not needed even in the G80 Govlock 70s axles, and many think that the non additive oils lubricate better with less wear (I have seen no proof of this however). Heat tolerance and shear tolerance are prime reasons to go with a couple of my favorites. I just went through the whole thing again as my old Buick Roadmaster now has a non clutch limited slip axle with limitations on using slip additive because of the design. Both of the old favorites don't have additive so good there.


Redline 75w90NS synthetic gear oil (ester based)


Motol 300 75w90 synthetic gear oil (ester based)


One big thing the truck folks do is to make sure that the truck is as far nose down when they fill the rear axle as that will allow a slight amount of overfill. The overfill is said to be just enough to make more oil go down the axle tubes to the axle bearings which are lubed with the differential oil by splash. The other thing they do is mostly on the full floating axles like the 70s, but would also give and early oiling to the 60s, I think. Once they have the axle slightly overfilled they jack up one side of the van to get as much side to side tilt as possible, or park it on a steep ditch, to run oil to the axle bearing on the down side. It is particularly important on the full floaters if the wheel bearing have been replaced or cleaned and adjusted because the hubs have a small reservoir in the bottom of the hub to hold oil that needs to get full of oil before driving. Repeat on other side.


Will it make the axles run cooler and last longer, probably, but nearly impossible to tell for certain.



On a Dana 60s it always pays to keep track of the rear hub temps, I think, especially with the aluminum wheels. If one starts to climb get it looked at right away as the bearing has no inner race and runs right on the axle. If it seizes or weakens the axle enough to break the axle the entire wheel can separate from the van which is really bad thing. The 70s full floater does not carry any weight on the axle shaft, just on the floating hubs, so it they break an axle (extremely rare) you just coast safely to a stop.