Thunking From The Rear End?

[jro909]

I've developed a kind of mild thunk sound recently with the big drop in temps, i can hear it on and off while coasting slow in a parking lot..on the highway i don't hear it at all, what it reminds me of is the thunk from the slip yoke but not as harsh, its coming from the back end of the truck some where, and my truck will make a similiar sound when i step out of the cab which leads me to think the springs are just stiffened from the cold...packs themselves looks good, i also thought maybe it was the back pads but they look fine and the truck brakes fine...any ideads?

[ChevyTech77]

Cold snaps make vehicles develop some crazy noises sometimes.

 

Probably just some snow and ice build-up between the leafs. Mine make all kinds of noise in this weather.

[8.1HD/ALLISON]

+1 wait till it warms up and see if the noise disappears.

[jro909]

so i'm almost positive its from the springs in the back...i drove home tonight and the roads are covered in speed bumps from the plows warping the roads and my god that sound makes me cringe..what causes the thunk sound? is it the springs slapping together or what? i'm always thinking to myself "is this going to be the bump that snaps the spring off?" lol...thanks for the replys guys

[blevenson]

Have you checked to make sure your spare is fully inflated and cranked up all the way?

 

I had the same noise, dealer chased it multiple times, changing the bump pads on the springs, etc and it didnt go away. I finally lowered the spare to take a look and the spare had flat spots where it touched the frame and the rim appeared to be in contact with the frame on big bumps - hence the noise. I checked the pressure and it was down to about 30 psi. Reinflated, rotated so the frame wasnt on the flat spots, cranked it back up and the noise is gone.

 

Cheap easy fix if it works for you.

[tanked_darren]

Trucks getting older, wait and let develop

[BlackZ71Silverado]

Check your leaf spring packs. I had one break on me on my 2001 Silverado and it would do what you are describing.

[jro909]

Have you checked to make sure your spare is fully inflated and cranked up all the way?

 

I had the same noise, dealer chased it multiple times, changing the bump pads on the springs, etc and it didnt go away. I finally lowered the spare to take a look and the spare had flat spots where it touched the frame and the rim appeared to be in contact with the frame on big bumps - hence the noise. I checked the pressure and it was down to about 30 psi. Reinflated, rotated so the frame wasnt on the flat spots, cranked it back up and the noise is gone.

 

Cheap easy fix if it works for you.

 

no spare, it was cut off awhile ago

 

Trucks getting older, wait and let develop

 

its old but the springs aren't really put through much, i have barely ever put alot of weight on the springs

 

Check your leaf spring packs. I had one break on me on my 2001 Silverado and it would do what you are describing.

 

they look fine, still attached to the truck, packs still shackled together and the ubolts look fine also

[[email protected]]

Mine did that, turns out I had a plastic piece go missing on top the overload and everytime I hit a fair bump the spring pack would slap the overload and make this pingy sounding thump.