rear diff or wheel bearing

[elcapitanmas]

Hoping for some good news from someone here. I have the 60-65 mph whine on my 02 and its going in tommorow. I have a long trip a month from now and want to get rid of whatever the problem is before I need a 500 mile tow. What Im wondering is, has anyone had the whine ever turn out to be low fluid in the rear diff? There isn't any noticeable clunking or drive issues other than the "high" pitch whine from 60-65. Im keeping my fingers crossed that the diff is low on fluid and its not a wheel bearing. Any similar experiences and outcomes are greatly appreciated.

Thanks
E

 

[thepotroast]

The rear diff whine isn't due to low fluid, it's due to worn parts, specifically the clutch pack (on an LSD) and worn ring and pinion. Not a whole lot that can be done on the fly except put some good name 75w-140 with extra friction modifier (again if you have the LSD) and see if that quiets things down. Don't have the shop put in anything other than 75w-140...75w-90 won't cut it.

If it is the rear diff whine, it's not a ticking time bomb...it won't explode, and it's more of an annoyance than anything.

You don't really provide any details other than noise at 60-65 so it's hard to diagnose that. Does the noise go away when you let off the accelerator, does the noise increase or decrease when you're in a turn, etc?

How many miles does your truck have?

 

[my pos mounty]

The rear diff in the third gen Explorers are notorious for whines due to bad bearings in the diff. Like thepotroast said, it isn't going to explode and leave you stranded 500 miles away from home. Be prepared to drop over $1800+ at a Stealership, but theres a much better way to do this. You could message ericautopart, he is a forum vendor and is selling rebuilt rear diffs for the third gen for 895-995 shipped to your door, or to the shop of your choosing. You could check this thread for more information if you so choose.
This is of course, IF your diff turns out to be toasted

 

[Beachguy910]

I just wanted to chime in and say I bought one of those rebuilt differentials from Eric who posts here for his company. Mine was $895 delivered and it came in two days. I removed the old one from my 02 explorer in 5 hours using normal tools that any of us would have. The next day it went back together again in about 4 hours. I was hesitant to tackle the job but it was much easier than I thought it would be. My truck is quiet like it was brand new.

 

[EasyRhino]

Mine has been whining since new in 2002. Now at 104K miles 8 years later it is the same - no better and no worse.

I did not replace the diff. fluid until 100K miles (w/ 75W-140) and it made no difference in the noise.

I'm not going to spend another penny on mine until it grenades and I'm betting that it will not.