Cold Start Squeal (Rear Axle Seal Leak?)

[DC-3G]

My '02 SR5 (99k mi.) has developed a mysterious and annoying squeal I can't seem to diagnose. The symptoms are:

1. Only occurs when it's moving (never when it's sitting still, regardless of revs)
2. Occurs even with engine off (Going downhill in Neutral w/ engine off, it starts when I hit ~20mph)
3. Always occurs when I first start driving, but it sometimes goes away on warm days after I've been driving a while
4. Seems to be altered by braking (Tapping the brakes sometimes stops it altogether and other times seems to stifle it).

I'm suspecting the common rear axle seal leak problem, but, since it sounds like most folks who've had the same problem were alerted to it by their mechanics, I wanted to make sure I was barking up the right tree before I got too far.

[I appreciate any help anyone can provide - I've had so much success looking at other people's posts that this is my first]

 

[BigFishAllDay]

I'm assuming this sound is coming from the rear axle? (you didn't mention that in your post)

This doesn't sound like a rear axle seal problem (usually those don't make a sound)... although it's easy to tell if yours is leaking. Look on the inboard side of the tire and see if there is grease (gear oil) being sprayed outward radially on the tire. You'll see it immediately if it's been leaking for awhile. If not, you'd have to remove the tire and pull the drum and see if it looks wet in there.

If you can pinpoint which side it's coming from, I'd start by checking to make sure the ebrake isn't frozen in place (rust or something), then check the shoes/drums in the rear to make sure everything looks ok. Could just be dirty, could be time for new shoes and a resurface/replace on the drum.