Posted by Steve Elliot on Sunday, October 03, 2004 at 4:07PM :
In Reply to: How hot is HOT (Rear differential) posted by Dave in Plano, TX on Sunday, October 03, 2004 at 2:38PM :
From Alan Bowes in the archive:
Well, it depends on what you mean by "hot," since they'll always develop some heat. Drain the old lube out and check it for metal particles. Swish a magnet through the oil. You'll always get a few particles, so don't panic, but if you see a good buildup on the magnet, you should pull the carrier and have a close look. Also check the condition of the oil. If it's kind of a milky brown, it almost certainly has water mixed with it in a colloidal suspension, in which case who knows what that may have done. Fortunately, a banjo-type rear end is easy to work on, since you can put the whole carrier assembly on a bench to work on it. If there aren't many metal particles, and the rear end doesn't make any whining (or other) noises, I'd suggest replacing the lube with a good synthetic gear lube and see if it makes any difference. If there is a noticeable reduction in temperature, then you might be OK. Water is a frequently seen problem...not just from fording streams, but from condensation. This varies with where the unit was stored and in what kind of climate. Water in oil causes rapid wear on all components, not to mention pitting and corrosion and excess heat.