I have a 2003 GMC YUKON 5.3 4x4. I have about 25K miles on it and I notive that when it shifts it has a "clank" noise at times. It doesn't always happen. Seems like it happens more when under load and shifting. Anyone have any ideas?

Thanks

 

My 99 does the same thing, had it looked at 3 times under warranty, to no avail. there is a TSB that statea as follows:

During a 2-3 upshift, the 2-4 band is released and the 3-4 clutch is applied. The timing of this shift can cause a momentary torque reversal of the output shaft that results in a clunk noise. This same torque reversal can also occur on a 3-2 downshift when the 3-4 clutch is released and the 2-4 band applied. This condition may be worse on a 4-wheel drive vehicle due to the additional tolerances in the transfer case.

This is a normal condition. No repairs should be attempted.

I feel it's a load of hoo-hah, but my truck has been making this noise for 5 years with no problems. It couldn't hurt to get it checked out if you are still under warranty.

There is also a bulletin about replacing the rear slip yoke with a nickel plated one, but it only applies to the 99-02's.

Hope this helps.

 

My 03 does same thing.thought it was ujoints, but they are fine.The conditions listed in tsb are exactly the same as mine. 11200 miles on mine, and its done it since it was new.Oh well ill just beat on it more till something breaks.

 

My truck does the same thing. At first I thought it was the U-joints as Avalanche said, tightened them. Then, I thought it was loose transmission bands. I talked to a GM mechanic and he said it's normal for these vehicles to have this "clunk" and it won't hurt anything.
Philip S.

 

Yup, my last few have done this. I personally think it's all the free-play in th 8.5" rear ends.

I mainly get the clank going from drive to reverse. Every once in a while I'll get it at parking lot speeds, on the 1-2 shift.

I heard a trick about greasing the splines of the slip yoke. The idea was that the slip yoke was sticking on the tranny output shaft. I dropped my driveshaft to find a good amount of ATF in the slip-yoke, so I didn't think it was a lubrication problem.

 

You might want to check the slip yoke. There was an update done on the slip yokes changing them because of that noise to a nickel plated slip yoke. My noises were cleared when this update was done through gm.

 

thast not for a clunk from drive to reverse, its a bump squawk, like going over bumps and when stopping. im going to say its normal, every 4x4 ive driven has had some sort of clunk

 

I don't know if my clunk is the same as your clunk, but every once in a while,, when I am going slow through a residential neighborhood and let off the gas, then get on the gas again, I get a clunk. Same thing happens on the freeway when I let off the gas and get back on it again. Makes it seem like the driveline is not as tight as it should be. Most of the time it doesn't do this, but sometimes it does (15-20% of the time). I find it disturbing. Does anyone have the clunk I am talking about?

 

Hey naked mine does the same thing as you described.Also if yu can hear over that blower,or turn your radio down yu will notice it alot more.

 

Try changing the fluid in the transfer case.....mine clunked for 2 years until I changed the fluid out for the new Autotrak II fluid, once I changed the fluid the clunk is completely gone