When is it necessary (milege interval) to repack rear wheel bearings?

[robbie]

I ahve seen a few high mileage truck come in where the rear inner axle seal had failed and there was not grease but gear lube. the hub seal was not weeping oil, the bearing were a lot easier to clean. and they looked good. The races were not pitted, or scored on most. One or two were beyond saving. Even these bearing that have 175k mils on them are servicable. But they did do some damage. I would not reccomend this milage before service. As for running with grease and no inner axle seal, it might be a good experment for some one to try. I too, do not read that Idaho Doug removed the inner axle seal on purpose to allow the gear oil to mix with the grease. So Doug is that what you did?
Yes more money for the shop, but hard to tell the customer he is a dummy for not maintaining the truck. He was taking it to a lexus dealer for the last several years with a maintance plan. Are they the one responsiable then and not the customer. Some thing for him to decide. later robbie

 

[landtank]

I had a rear oil seal fail from someone installing it backwards . Oil leaked out through the rear hub bad enough to trash the rear brakes. I personally wouldn't try running with no oil seal.

 

[IdahoDoug]

No, I didn't remove any seals. This was simply the way I found it when I repacked the rear wheel bearings for the first time at 100k. The inner seal had worn completely and there was no external leak or sign of it at all. It had Mobil 1 in the rear axle since breakin miles were completed, so when the seal began leaking internally, the rear wheel bearings were rinsed clean with it and then ran happily in it. I replaced the seal and packed the bearings with Mobil 1 synthetic grease. Will be interesting to see when I open it again.

Edit: Interestingly, I think the rear diff had been drained and refilled 3 times during this period and always came out perfectly clear - no indicator that grease was being rinsed into the gear oil. Simply due to the relative volumes, I suppose. The grease volume of a pair of rear wheel bearings would easily be lost in the larger rear diff gear oil volume when compared to the huge grease volume of the front birfs and the smaller front diff gear oil volume. So, if you're wondering about your own vehicle and are being attentive to the rear gear oil, clean oil would not contraindicate this seal's being worn out.

DougM