Sound identification

[lduffner]

Can anyone help identify a strange sound that I get from my 08 3500? Sometimes after completely stopping in traffic, transmission in D, ( in city driving) I hear a single thump sound coming from under the truck in approximately the middle of the truck. It is a low decible sound that occurs only once. (the exhaust brake is not engaged) It doesn't sound like a brake issue and it isn't coming from the engine compartment. I don't hear it when on the highway or while towing my fifth wheel. Could this sound be associated with the regeneration process?

 

[sag2]

It is most likely the slip yoke to the transmission output shaft. It should slide smoothly in and out of the trans, and if it doesn't it makes a thump as you come to a stop and it releases. Pull the yoke out of the trans (note the relationship to the output shaft to avoid runout and associated vibration) and apply anti sieze to the shaft and reinstall.

 

[lpagano]

It's the fuel sloshing in the tank, it is most noticable at about the 3/4 full level. There is a tsb addressing this and both my 07 and 07. 5's do this.

 

[TulsaOkie]

I had the same kind of sound, and my spare tire had came loose.

 

[DieselLady]

Me too, but I know my spare is not loose.