I own a 5 cylc 2007 hummer H3. I recently replaced my front differential which cost me about 2000 dollars. Once it was replaced, the hummer was drivable, however, i started hearing a rattling noise under my seat when ever i release the acceleration pedal. It only does this when the car is coasting or moving in netrual, once i hit the acceleration pedal the noise goes away and everthing sounds normal. I took it to the same mechanic that replaced my front differential and he told me that the transfer case needs replaced because the chain is hitting the iron casting but is not binding or anything like that. He also said that for now you can drive it but it will eventually blow out. I kind of dont want to spend another 2 grand on this and am hoping that some of you ran into this problem and found an alternative way of fixing it.

This problem was not there before until i replaced the front differential. Perhaps the mechanic did not install it correctly?? any feedback would be much appreciated.

Thanks!!!!!

 

i doubt that anything done outside would affect the chain inside???
its something loose?

 

The other scenario... was the problem really with the front diff? You did not describe what led your "Mechanic" to diagnose the diff instead of the T Case, or if the nature of the front diff failure could have thrashed the T Case on the way out.

We would need to know more info before randomly guessing. Whenever a question is asked, include MODEL and MILES.

Is your 07 a Base, Adventure, Lux, or Lux Off Road? That tells us which T Case you have and miles indicates the wear point.

 

Sounds like chain slap.