Low Vibration/Rumbling Sound

[gmenor]

I was just in my friends 1500, 97 Gasser Suburban and noticed a low rumbling/vibration sound from right rear. He said that it started about 3 weeks back, had new tires put on since and it still has the vibration. It starts about 45-50 mph, does get any louder. He had the brakes, tires rebalanced and still it persists. Any thoughts on what it could be? Has anyone experienced the same sounds? Probably posting this in the wrong place.

[tanker]

I would check the wheel bearing. 1500's have the lighter duty rear axle, and won't take as much abuse, or weight as the full floating 2500 axles. Could also be in the rear differential, spider gears, pinion bearing, or possible U-joint going bad. Noises can travel, using anything metalic to transfer the sound.

[gmenor]

Tanker, Thanks for the response. Just for my information I have 1500 6.5 TD. This does not pertain to the 6.5's? As I understand it diesel have a heavier suspension system (8 lug verse 6 lugs).

[patrick m.]

axle bearings and/or differential case side bearings, that is if the noise doesnt change from accel to decel.

[gmenor]

Well since I am on travel with my friend up here in Baltimore, MD the noise has increased two fold. We took to GMC dealer - too busy. He suggested Buick cause they are never busy (liar). The Buick mechanic took time to check it out and he said differential needs to be replaced. The whole thing now vibrates and has a low hum that can be heard throughout the Suburban. The mechanic says it is $2k job and he could continue to drive it until he can't stand the noise. I'm flying back and my friend is driving back to Virginia Beach Saturday. I can't believe that it will cost that much. You would think the parts are made of gold and manufactured only doing a leap year.