Well i'm not exactly sure where it is comming from, but it has to be something moving in the rear of the truck. It has only happened about 5 times and is spread a part. Kind of sounds like I hit a pot hole or something BUT i'm 100% sure that is not the case. It has happend both speeding up and slowing down. Its a 2004 hemi 4x4...Any idea's would be great. Could it be from being in cold weather and switching in and out of 4x4?

 

change differential fluid maybe?

i work at a bar, and this guy claims he had liek 100k on his truck, and when he went into dealer for the scheduled whatever it is, they said there was no diff fluid...but...i work at a bar, and people blow smoke up your *** all day...

 

Yeah maybe i'll try that. Happened again this morning. Kind of sounded like a rough shift for more of a better description, but it wasn't...

 

Mine did this too the other night. I just started it upand romped on it for about2 blocks and felt it when i slowed down.Don't have a clue what it could be...

 

I'm gunna change the diff fluid this weekend and see if there are metal chunks...

 

I would check the U-joints first. Park your truck with the engine running and put it in gear. If you don't hear anythig try reverse. If it makes the same noise it's most probably the u-joint.
You can also get under your truck and try to move the shaft with your hands and see if you have any play.

Good luck.

Tomski