98 tahoe "bump & clunk" drivetrain problem

First post!

My 98 Tahoe has what they call a Bump & clunk in the drive train. It is most noticeable upon take off and when you come to a complete stop. Taking off, if you nurse it slowly it won't do it. It has 94k nearly all highway and is still very tight in every other way. The U-joints were just replaced. Any help please?? Thanks Tom...

My '95 2Dr 4WD just started doing the same thing - and like you, the u-joints were just replaced also (like a week earlier). I am keeping my fingers crossed that it may be a bad u-joint (not likely). I've got an appointment at a garage Thursday hopefully they can find the problem.

What worries me is; a friend of mine had a '99 escalade that had the same problem, his dealer suggested it was 'play' between the tailshaft of the tranny and the yoke of the driveshaft and that it is a common problem. I will try to let you know what I find out.

They have also told me about "extra play" in the Yoke but that is a common problem and does not cause any other problems. I know there has to be a cause for this other wise why wouldn't everyones do this? Thanks Tom...

Mine does the same thing, I repled the u joints, think there is something loose in the rear end.....

a temporary fix is to remove the drive shaft and install a small amount of GM special lubricant to the splines on the slip joint, should last 6 mths to a year depending on driving habits. the cause is the slip joint binding on the trans tail shaft causing the noise and bump feel. you can also use a brake lathe bit and clean the grooves between the splines on the trans output shaft and the drive shaft slip joint if you dont want to spend $50 for the can of GM special lubricant. the can will last you forever and takes just the removal of the driveshaft and your done.

Thanks! I'll try that this week and let you know. Also thank-you for taking the time to answer. Tom...

First post!

My 98 Tahoe has what they call a Bump & clunk in the drive train. It is most noticeable upon take off and when you come to a complete stop. Taking off, if you nurse it slowly it won't do it. It has 94k nearly all highway and is still very tight in every other way. The U-joints were just replaced. Any help please?? Thanks Tom...
There has been an update on the rear end gear oil. Call your dealer about it. My 99 was doing it and when i took it in they had just got the notice.

I have a 99 Tahoe with 33370 miles on it. The clunking noise you describe is the same in my vehicle. Have not had it diagnosed as of yet. Still trying to recoupe from my busted transmission which happened a week ago. Has anyone else had their transmission go bad at 33370 miles?

First post!

My 98 Tahoe has what they call a Bump & clunk in the drive train. It is most noticeable upon take off and when you come to a complete stop. Taking off, if you nurse it slowly it won't do it. It has 94k nearly all highway and is still very tight in every other way. The U-joints were just replaced. Any help please?? Thanks Tom...
My 99 Tahoe had the same problem. Just came back from Chevrolet Repair. My problem was fixed simply by lubricating the slip joint. There is a Bulletin out on this problem.

What's so "special about the GM Special Lube? What type of lube is it? gear oil type, grease type, ATF type?

My bump and clunk on my 99 Tahoe is back. GM lubed the slip joint. It was ok for a couple of days, but the noise is back again.

I have a 99 Tahoe with 33370 miles on it. The clunking noise you describe is the same in my vehicle. Have not had it diagnosed as of yet. Still trying to recoupe from my busted transmission which happened a week ago. Has anyone else had their transmission go bad at 33370 miles?

I have a 2000 Tahoe Limited, I had the same problem. Took it to chevy they said "the slip yoke just needed to be lubed," which temporally fixed the problem. A week later, with about 42000 miles on the car, the WHOLE tranny needed to be replaced. Havent had said bumb/ clunking noise when I come to a stop since....

What was your problem with the tranny? Did they fiond a bad sun gear?

I didnt ask about the tranny. All I know is that when I took it in I couldnt shift into reverse and they dropped the pan on the spot and it was filled with metal. If it was a bad sun gear, there wasnt much left of it. hehe

I pulled my driveshaft and im going to lube the slip-yoke with Almaplex industrial lubricant made by Lubrication Engineers out of Fort Worth, TX. I got this at work and it is supposed to be one of the best lubricants ou there for water resistance, heat resistance, rust and oxidation inhibited, and has Almasol in it! Ill let everyone know what happens.

I've got the same problem with my '99 w/ 77,000 miles, I had a 96 before w/ 110,000 miles and never had a problem!

Please post here if anyone finds what seems to be a permanant fix!

I am new to this forum so please pardon my late reply.
My Tahoe has this same problem and I was able to find a TSB for this.
TSB No. 01-04-17-004 dated October 2001

Here is some good info

http://www.startribune.com/stories/435/3856014.html

I pulled my driveshaft and im going to lube the slip-yoke with Almaplex industrial lubricant made by Lubrication Engineers out of Fort Worth, TX. I got this at work and it is supposed to be one of the best lubricants ou there for water resistance, heat resistance, rust and oxidation inhibited, and has Almasol in it! Ill let everyone know what happens.






Lubrication Engineeres products are unbelievably superior to other lubricants! Ive used them for 17yrs and never wore out any parts!
I use their power fluid in my transfer case, auto-tranny, and power steering. Gear oil in my diffs. Their engine oil also. If you keeps a vehical
for a looong time, use their products, it deffinately will save you money in the long run!!!
Roger.

i have 2 tahoe's a 96 2 dr deisel 347,000 miles, and a 98 4 dr gass 177,000 miles, both make the same noise, you have to tighten up the pinion gear nut on the rear, typical for all GM's, and change your tranny mounts along with your motor mounts, and make sure that your drive shaft input shaft is lined up rite, there is a keyway with different size grooves that will fit when its not lined up rite, but have some play, but when lined up correctly, will fit like its supposed to. good luck and please maintain your trucks, they are great trucks, but only when maintained propperly, grease all fitting, and change mounts and all joints every 50,000 miles.i also replaced my leafspring bushings with urithane ones, less movement and last longer.