Strange noise in a 2004 toco

Hi maybe someone has heard this and may know what it is. When I decelerate I get what I would say is a vibration rumble sound coming from mid passenger side. In doesn't do it at idle, accelerating, coasting in neutral or at a constant speed. There is no loss of power and its not from the wheels. Could it be something in the exhaust system? Heat shields? I have not been able to pin it down. Any thoughts? Thanks Bill

 

Exhaust suspension bracket or the cat. Any check engine lights?

 

U joint....carrier bearing???

 

Thanks for the response. No lights on. Makes noise in deceleration in gear only. If it was in the drive shaft wouldn't it make the same noise when accelerating? The noise is louder out the passenger side than equally on both sides. Are there any heat shields that can vibrate loose? Thanks for the thoughts Bill

 

no because it wears under load so on deceleration it unloads more then just coasting in neutral.

I agree with bry838 check the u-joints and carrier bearing for looseness or play

if you find nothing then check rear end and tranny fluid levels

 

Thank you I will check these items out. Bill

 

Thanks for the help. I took the truck to a drive shaft shop and they replaced the center bearing, u joint, stub/mates with 1301-231 flange,companion flange/mates with 1353-231 stub, balanced and greased all fittings on the shaft. No noise or vibration on the way home. The real test will be when I load up the bed with my 1100lb slide in camper. Bill