Need to fix this fast...stranded at home, need to get back to school!!

[Madbomber88]

My 90 K5 has a vibration that is getting much worse at low speeds around 20-30 mph. Maybe at higher speeds the noise just gets drowned out. I was on my way to school (6 hour trip) and turned back because it was getting worse. You can only hear it from inside the truck and it is coming from the rear. U-joints seem rock solid. Pulled the drums on each wheel, and everything looked fine but there was a little leakage around the wheel bearing and I could pull the hub in and out about 1/4" So question is this...truck has 160,000 miles on it, very well maintained by previous owner. Do you think it is the differential bearings, the u-joint, or the wheel bearings. I have one day to fix this before I have to be back at school (only a month to go before I am done for good). If it is the differential bearings, how much are they? Thank you in advance. -Tim

 

[Zeus33rd]

I would lean towards U-joints. How long since they were last changed out? I had a similar problem awhile back, Vibration at about 45-50 mph. I did the same as you, Crawled all over under the truck tryin to figure it out. After awhile, I just said F-uck-it and gave up. About 3 weeks later the u-joint on the transfer case end let go right in the middle of a busy intersection. Put a huge dent in the floor of my truck and I had to run to AutoZone, which was thankfully right on the corner in the same intersection, grap a couple u-joints and switch them out in the middle of the intersection. I thought I had checked the u-joints while crawling around, And they had "seemed" pretty solid. What I'm gettin at is that appearances can be decieving. Change out them u-joints anyways. Even if it doesnt fix the problem, its good to have the piece of mind knowing that they are new. There pretty cheap and easy to change as well. /forums/images/icons/smile.gif Hoped that helped ya out.

 

[jimmyjack]

Don't overlook a wheel balance problem either, I've fixed a lot of headaches just getting them rebalanced.

 

[GMCLegacy]

put the rear axle on jackstands, and put the truck in gear with someone in the K5, then look to see if what is making the noise while the truck is in gear. this may not be the safest thing you have thought of, but it may save you money throwing money and parts at your truck.

 

[chevy737]

I had a similar problem with my '91... went through that same process... but found out I had a bum spark plug wire that was breaking down under a load. It made the truck vibrate like crazy when I gave it gas. I know sounds strange but it's definately worth a look and good excuse for a tune up.