Can't find "clunk" - K2500

Almost sounds like the clunk I get with my 99 Silverado. I was told that it had something to do with the yoke engaging in the transfer case.

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Can't find "clunk" - K2500 Group: alt.autos.4x4.chevy-trucks Date: Thu, Oct 9, 2003, 1:17pm (CDT+1) From: somethingorotherdotcom (Snowman)

(vehical) '95 K2500HD EC/LB 6.5 TD/4L80E

(symptom) I've got this low, dense clunk that I hear daily after driving over about 50-55 mph for a mile or longer while coming up to a stop sign. I usually coast a little while, then start to hit the brakes and at about

20-30 mph upon the deceleration, I hear it one time only from the front end, "clunk."

(visualization) This resembles a heavy cast part hitting another very heavy part, but I can't duplicate it unless I am driving on the road.

(diagnostic steps taken) I've tried jacking it in the air in the garage and bouncing a 4x4 under the tires to try to simulate a vibration, tried listening with the window down, etc., but to no avail.

(further diagnostic input) I feel it up through the floorboards, it's so intense.

(insight into customers state of mind) I can find no evidence of anything wrong, though, other than the noise and I'm just afraid it's going to break something some day and I'm going to have a real mess on my hands.

(brief maintenance history) I've had both spindles detached from the upper ball joints for pulling both front half-shafts and have replaced the pitman arm back in March. I've put 6,000 miles on like this and it doesn't seem to get better or worse. any suggestions on something I can check?

(admittal of confusion) Pretty vague, I know, but I'm scratching my head on this.

(random thoughts) I thought about posting it here a while back, but it's almost impossible to describe something like this. Only happens in the above scenario. thanks in advance,

Snowman //////////////////////////// Snow, you have to have the "sprung weight" off the suspension to check the ball joints....... meaning you need to lift the wheel under the controll arm, in order to take tension off the ball joints to see if they have any play in them.

Spring tension will keep you from finding even a very worn ball joint.

However..............

are you sure it's coming from the front ?

The reason I ask, is because you stated you can feel it in the floarboard.

have you noticed any shifting problems...... maybe a little more solid on the shift points than it use to be???

If you're feeling it in the floorboard, and it's pronounced, before I went digging into the front end I would take a look at .......

tranny mount

drive shaft slip yoke (looseness=pack it slap-ass full of grease)

u-joints

drive shaft center support bearing (aka...carrier bearing, hanger bearing)

transmission (downshift clunk)

It very likely could be a frontend part going on you.....but if you're getting it through the floor board, I would take a quick gander in that area first.

jmo

respectfully to the.....snowman

marsh monster .

20-30 mph upon the deceleration, I hear it one time only from the front end, "clunk." This resembles a heavy cast part hitting another very heavy part, but I can't duplicate it unless I am driving on the road. I've tried jacking it in the air in the garage and bouncing a 4x4 under the tires to try to simulate a vibration, tried listening with the window down, etc., but to no avail. I feel it up through the floorboards, it's so intense. I can find no evidence of anything wrong, though, other than the noise and I'm just afraid it's going to break something some day and I'm going to have a real mess on my hands. I've had both spindles detached from the upper ball joints for pulling both front half-shafts and have replaced the pitman arm back in March. I've put 6,000 miles on like this and it doesn't seem to get better or worse. any suggestions on something I can check? Pretty vague, I know, but I'm scratching my head on this. I thought about posting it here a while back, but it's almost impossible to describe something like this. Only happens in the above scenario. thanks in advance, Snowman

try this i had one last week that did the same thing there is a cross member towards the front held on with four bolts when they drilled them out at the factory they didnt get the burrs off.Take it down and grind down the wholes removing any burs coat the bolts in the copper stuff you use on head bolts and put it all back....I thought this was the stupidest thing in the world untill i tried it and it worked.It may work for you ..

I had that exact problem in my 92 Z71. Had it to the dealer 4 times until I finally found the problem myself and brought it back for them to fix. Of course they still couldn't figure it out even after I told them the problem until I started yelling and cursing. Anyway on my rig I got the clunk only once upon deceleration to a stop, usually just before I came to a complete stop is when I got it and only after driving for a while or after a hard acceleration. I could feel the clunk in the floorboards but just a little. Turned out to be a loose upper control arm. I found it by grabbing the top of the tire with the truck on the ground and pushing and pulling until I got a motion going and you could see the upper control arm moving slightly at its mounts. Good luck and post what you find. JRE

i also have a clunk on my blazer and have heard i should try to grease the slip yoke. Only problem is that im not sure exactly where it is, pardon my ignorance, and what type of grease should i use? BTW it is a 2002 baby blazer