Ok Guys, have a 2wd 99EB 5.4 with 105,000 miles. Last week I started hearing a drive train noise, sounds like axle whine. This week it sounds louder, maybe because I'm paying more attention to it. Anyway, it begins around 20 mph up to about 45 and you can really hear it on deaccleration from 45 to 15. Attempting to isolate the sound, going about 40 where the noise is the loudest I put the transmission in neutral and varied the engine RPM's with no change to the whine noise. So, I'm thinking the noise is axle or differential related.

I serviced the rear differential at 91,000 miles about a year ago and everything looked fine, about 6 months later I had a leak around the pinion yoke seal. Unfortunately, I had the dealer replace the seal.

I've search the forum and found some of the 03 - 05 guys having problems with axle whine but didn't find any of the older 98 -00 having axle whine problems.

My question, what causes the whine and is it damaging anything in the drive train that needs immediate attention. Or is it something that is not causing mechanical problems and I can just live with the noise?

Thanks

 

First, I'd double-check to make sure the rear differential fluid level is accurate. If it is full, & nothing else seems obviously wrong, you might want to have a mechanic look at it.