clunk when traveling over bumps or releasing brake from complete stop

[00YukonSLT5.3Rwd]

Obviously I have a 2000 Yukon 5.3 2wd. At 155k I lost 2nd gear and had trans rebuilt. Also they installed a hd torque converter. About 6 months ago I started developing a clunk. Over speee bumps, now and then when I let off brakes at a stop sign. Backing out of my driveway does it. I serviced the rear, checked the ujoints, replaced shocks and rear sway bar links. I read on a post the yolk is the cause or transfer case. I don't have a transfer case. If I pull the driveshaft and grease the shaft will that be a fix or do I need a new drive shaft? Or is it something else? I just dont want to keep throwing money into it and still have the same problem.

 

[SLCHOE]

Check your motor mounts and trans mount.

Put the truck in drive with your left foot on the brake pedal. Now rev it up to about 1500 rpm. Have someone check for excessive engine movement. Do the same in reverse to check the other side.

The engine will tilt slightly when the mounts are good. If the mounts are broken or weak, the engine will "lift" excessively and usually make a clunk noise as you get on and off the gas pedal.

The trans mount you willl have to check from underneath. Laying under the truck, grab the trans housing and push it up and see how much travel it gets. You shouldn't have much at all. If it is broken, you will know.

 

[00YukonSLT5.3Rwd]

The mounts are solid. I have checked those. I have taken hitch ball off, checked spare is tight. It sounds like metal/metal contact. Sometimes even sounds like something binding. I was going to replace all the bushings next for trail/track arms. Then do coil springs. I am just tired of throwing money iinto the problem and its still there.

 

[treehan77]

it's not the intermediate steering shaft is it? i know mine made some crazy clunking at weird times before i "exercised" it, its been working with no clunks for a while now...

 

[H8 PVMT]

I had this happen, twice. First time I found a missing bolt from the tranny mount, replaced it and fixed. 2nd time I thought the same bolt may have got loose but it was all tight, bought a new tranny mount from Car Quest for 14.00 replaced it and it's fixed. Just by looking at it I wouldn't have thought it was wornout but I replaced it since I had it all apart anyway and it was only 14.00.
On a side note I searched forever trying to find that clunk. I replaced the mid shaft, new shocks, new sway bar bushings... headache.

 

[carcrz]

it may be your brake pads bouncing around the caliper, replace your hardware kit and see what happens

 

[00YukonSLT5.3Rwd]

At this rate I will replace $2000 in parts only to find it being something stupid. Sucks but it is what it is. Its been making the noise for a while now and getting worse. Not the brakes, noise was there before I put new loaded calipers on last month. It is related to suspension somehow. Traveling slow over speed bumps, backing out of driveway, starting from complete stop are the times I hear it most. Its very noticable sound. When The vehicle is loaded its not as noticable.

 

[afpj]

Just for shts & giggles, you said you did brakes but you check your ebrake? They make serious noise when the pad/shoe in the drum falls apart. Good luck.

 

[SLCHOE]

Have you checked your lower ball-joints for excessive play?

 

[00YukonSLT5.3Rwd]

I still haven't found the noise. Checked everything above mentioned and some. Just going to wait until I hear something fall off.