Rear axle seals

[LordAbbett]

On a 2001 2500 Dodge Ram, this is a Dana 70 w/10.5" ring gear. Full floater. I just changed one axle oil seal due to gear oil leaking onto the parking brake shoes inside the rotor. Of course the axle shaft got a new gasket when I put in back in.
Why do you need to pack the bearings with grease when reinstalling them? I always thought that if the differential was up to proper level then the axle tube had oil in the bottom and would lube the bearings. I packed them with Valvoline GM- Chrysler-European-[censored] grease. This the red grease. But I just wonder if it's really necessary?

[censored] is censored?? What's the world coming too?
Ok Valvoline GM- Chrysler-European and... Japanese grease

 

[pcoxe]

The lube from the differential walks up the axle shaft to the bearing while it is turning. The bearing isn't immersed in oil. You grease the new bearing to provide lubrication while fluid works its way back up to the bearing along the axle.

 

[LordAbbett]

I guess the grease has no effect on the gear oil?

 

[slammds15]

Some people say you are supposed to use lithium grease on the inner wheel bearing only. Which in theory makes sense. The grease will dissolve with the oil, not packing the outer wheel bearing will allow the oil to fill the hub in a quicker form. I myself only do this on the old GM rear wheel hubs due to the small oil capacity in the hub. Generally all I do is pre-lube the bearing with gear oil, set it in place, drive the seal in, set the hub on the spindle, fill the hub with gear oil until it is running out, pre-lube the outer bearing and install. After the axles are back in I check the diff level and top up if necessary, then tip the axles with the jack each way for 5-10 minutes while I clean up. Once that is done I re-check the level again.

I've seen 2 GM wheel hubs burn out bearing's, one was from no grease on the inner bearing the other from someone packing the outer bearing with wheel bearing grease, it does not dissolve in gear oil well at all. On a note for the GM hubs, it is [censored] near impossible to fill the hub due to the design.

 

[mechtech2]

Lubing them with gear oil is what I normally do.
If the factory says use grease, then do it.
Otherwise it should not be necessary.
If the system is OK, it is lubed by gear oil anyway.

 

[Kestas]

If you install the bearings and use the vehicle right away, I imaging lubing the bearings with gear oil should be good enough. Otherwise I'd follow the instructions and grease them to help with startup. Normal lubrication comes from the side-to-side motion of the vehicle.

 

[firefighter]

I lube the bearings, put it together overfill the rear slightly, then go out and pull sideways on a steep bank we have at work, then go the other way for a little. Never had a problem.

 

[Chris142]

Originally Posted By: firefighter
I lube the bearings, put it together overfill the rear slightly, then go out and pull sideways on a steep bank we have at work, then go the other way for a little.
I jack up each side for a few mins then recheck the level.

 

[onion]

In my experience, full-floating hubs with tapered roller bearings are a pretty forgiving design. I've seen them done 'wrong' more times than I can count, and USUALLY people get away with it.

I generally dip the bearings in gear oil. Slide the hub with the seal and inner bearing into place. Use a squirt bottle/bucket pump/whatever is handy/etc. to fill the space in between the bearings with oil (while holding the hub straight). Slide the outer bearing in place. Set the bearing end-play (I usually try for around .002" because it's convenient, within most manufacturers' specs, and easy to measure- but SOME heavy truck hubs with built-in spacers actually put a little preload on the bearings, and you just tighten the retaining nut down). Install the axles. Jack up each side, letting is sit that way for a few minutes. Top off the differential oil.

I deal with these on class 8 trucks mostly, with the occasional medium-duty truck or 3/4 or 1-ton pickup. There are numerous retaining nut designs, but the principle is pretty much the same on all of them.

Some people grease the bearings- it's pretty common. I don't think it will hurt anything most of the time (though I wouldn't over-do it on the grease), but these bearings are SUPPOSED to be lubed by oil. Grease is generally considered a fail-safe in case the bearings don't get oiled properly. But if the diff is full and you jack up both sides, that shouldn't be an issue.

 

[LordAbbett]

I torqued to 130 ft lbs and backed off about 1/4 turn which gave me about .003 clearance. spec was .001 - .010
Used a new nut with a new little clip that you tap in tp lock the nut. Should be good to go.
I appreciate everybodys input!!