pekin84

We have a 97 GMC Suburban that just hit 110,000m. We bought it used when it had 45K. W just started noticing a disturbing hum/vibration from the rear when car gets up to speed, especiallly bad at about 60 mph. Mechanic thinks it's a driveline balance issue. Upon inspection he noted weights and excessive amounts of grease above U joint. Suspects problem was there originally and attempts had been made to correct it in the past, unbeknownst to us. He was confident that the vibration was not from the tranny or differential. Most of our driving is small town local, with a couple long road trips per year.
Any thoughts??

Polly

flatcreek

We have a '95 Sub. with about 206000 on it. We have the same problem. I was hoping to find an answer on here also. We took it to the tire store and found out that the previous owner had put on 4 sets of tire and also had them hand balance the rims. No luck. They told us someone else had the same problem and they took it to the Chevy dealership and they somehow fixed it. If we find anything out I will let you know. And if you find out anything let us know! Thanks Gary in TN

sub006

On my '90 at around 200,000 miles, I had a nasty vibration. My trans shop found the rubber "donut" support (where the two driveshafts meet) was torn up, almost gone, and replaced it for less than $50.

This got rid of MOST of the vibration but it was a symptom, not the cause. A couple of years later the vibration came back with a vengeance. A local driveshaft specialist replaced all the u-joints and balanced the two shafts for about $250. I'm now approaching 400,000 miles smoothly, with no problems.

pappyl

Vibration problems in the driveline have can have many sources - so i'd start with the easiest first:
- balance your tires
- make sure your engine is in tune
- check your transmission mounts (rubber broke)
- check your engine mounts (ie: broken bolt)
- check your springs U brackets
- check your universal joints (4 in my burban)
- pull off your back wheels, check for play in your rear axle (should be very tight - any play= new bearings and possible new rear shaft)
- possible - inner bearings in the differential

note: I ended up changing my bearings - if you tow at all - expect this - keep your bearings and rear fluid up - your axles will be a-ok)