Clunking noise

[steppside69]

I have another question reguarding my 95 . It has a 5.0l with od tranny,the motor(orignal) has 240,000 miles on it and the tranny (2nd) has 90,000 miles. I have been slowly replacing the front end (ball joints, tie rod ends ect.) Ever since I bought the truck there has been a horrible clunking noise from either the tranny or the rear end. At first I assumed it was the u-joints but I took out the drive shaft and couldnt find a problem with them. The noise only occurs when I shift from park to drive, drive to reverse. The tranny seems to shift longer from 1st to 2nd but other than that I cannot tell any problems with the tranny. I dont know what the symptoms would be on the rear end going out. Any ideas?

[Palf70Step]

What about a carrier bearing? It took having mine fall apart to figure out the Klunk.

[steppside69]

There is no carrier bearing. I was talking to a friend nd he was saying something about greasing the tail shaft, thinking theree was an air gap between the driveshaft and the tail of the tranny. I tried to find a fitting but couldn't find one. Have you ever heard of that?

[TennesseeZ]

Sure sounds like U-joints to me.

[Boog]

Stepside, a common occurence with the 88 up trucks is the splines get dry on the tranny end of the driveshaft. Normally you hear and feel a clunk upon stop and or take off. You must drop the shaft and push a good grease up into the yoke splines to stop it. This may not be your problem but it is common to these models. Won't cost you anything but some time to try it.

[piecesparts]

Originally Posted by Boog

Stepside, a common occurence with the 88 up trucks is the splines get dry on the tranny end of the driveshaft. Normally you hear and feel a clunk upon stop and or take off. You must drop the shaft and push a good grease up into the yoke splines to stop it. This may not be your problem but it is common to these models. Won't cost you anything but some time to try it.

I have to say that I have been running GM turcks for a long time and my 91 has almost 240,000 miles on it and I hadn't experienced that one yet. However it never amazes me, the things that come out of the woods that I haven't seen yet. I personally, would still look at those U-joints. My guess is that there is a joint bad or the rear end has a lot of loose play in it. The clunk is the drivetrain taking slack up in the change of direction in the rotational movement. Heck with the miles that you have and the fact that you do not know all of the truck's past history---I would replace the U-joints to be safe. If the driveline drops on the highway, it can be quite a show, not to mention expensive.

[wedgemon]

I've posted my experience on the "Click/Clunk" before, But I can't find the post.

So here goes. (Short version summary)

Had a 91 Caprice, clunked on stop and start, into and out of gear as well. Turned out that I cracked and almost spun the center of the flex plate (where palm of crank bolts thru) completely separate from the rest of the plate. It had just enough interference that it would spin the T/C and move the vehicle. But, The clunk got progressively worse and would have eventually spun free.

Pull the inspection cover and shine a light up in there.

This problem audibly sounds a LOT like U-joints or mounts!!

Good Luck!

- Dave

[steppside69]

Thanks for all the info, will lookin into it more throughly after the weather warms up a bit only 13 degrees at the moment

[bwood]

I had my local GM dealer tell me the same thing on greasing the tailshaft. My 98 did it under warr, but instead of in and out of gear it was at takeoff from a light or rapid stop. They used a GM "special" grease. It started doing this again about 3 years later and they gave me some of the grease (it come in large tubs) and it fixed the noise. I do have to ask, is the noise just with the truck sitting in one position (ie on an incline). I have heard noises like this in many different makes and models with auto trans. Here is a example, my Mom would park her 88 GMC Safari van in the drive (incline) and not set the parking brake so every time she would get back in and shift into gear, it would pop/clunk (sounded like someone hit the bottom of the van with a hammer. When she parked and let off the brake the truck would settle against the insides of the trans (park was actually the only thing keeping it from rolling) so when she got back in everything was in a bind and would pop out to get in gear.

[72BLUZ]

try removeing the drive line from the rear chunk and jack up the rear end. turn the yoke back and forth by hand to see if you feel any resistance

[steppside69]

Just an update on the "clunking noise", I finally got around to geting the truck in the garage. I removed the driveshaft, checked the u-joints, They appeared to be fine I couldnt find any play in them. I grease the inside of the dirveshaft, put it all back together and took it around the block, The noise was gone!! I was wondering about back lash?????? I am happy with the cost of 0$$ just time to fix the clunk but when I put the truck into drive to reverse I still get a slamming feeling. I can stop it somewhat when I stand on the brake pedal and i do mean stand on it. I think this one will cost some money to fix, What direction should I go in now???
Thanks for the info again