Seal conditioners are already in the gear lube. The pinion shaft is up high enough that not all the lube is going to run out, but if the level is low, no lube will run out to the wheel bearings. Replacing the pinion seal is rather straight-forward and not too difficult so there's no reason to put it off. If it's leaking very badly, the bearing might be worn allowing the pinion shaft to move away from the seal. That will be a lot more costly but you should be noticing a howl.
The lube is also used for cooling. It's not unheard of for the differential to turn red hot when the gear lube was very low. Believe me, you would rather live with a pack of skunks than take one whiff of a burned up rear axle! Had one once that cleared the shop in no time!
Tuesday, April 19th, 2011 AT 10:27 PM