I've got a 2001 2500 4x4 with a Dana 70 rear axle. It appears to me that the rear wheel bearings are lubricated by the gear oil in the diff. However, the Haynes manual specifies packing the bearings with grease. Is it true that the bearings should be packed with grease? I would think that this wouldn't be the case if they're lubed with diff oil.

Don in Portland

 

I think the main reason for packing the bearings is so they get lubrication until the diff oil sloshes around enough to reach the ends of the axle tubes. It's a good idea to head for a parking lot and do some figure 8's after you repack the bearings just to make sure you get lots of oil out to them.

 

Or you could just jack up each side of the axle and let it sit for 15-20 minutes and then fill the pumpkin back up to the proper level. Caution must be used when packing bearings in full floating axles as the "hypoid" gear oil is NOT compatable with most greases and compromises the LSD clutches after mixing in the oil. Warranty will be an issue with some as they will blame gear oil contamination in the case of a diff claim. If you see or hear of a DC mechanic using this method of prelubing question the compatability of the grease and oil and have it noted and signed by the attending mechanic on the bill before signing off the work order. Otherwise he will say you OK'ed it therefore approving contamination. PK