Strange grinding noise on 05

[rzohr251]

I have an 05 LLY and I just recently began noticing a strange grinding sounding like transmission gears. I cannot feel any grinding like you usually would if it was the trans, and im not having shifting problems. The problem usually happens after I accelerate quickly and just after the turbo pops off. The noise will last for 5 to 10 seconds. Any suggestions??

 

[LBZ]

What sort of mods have you done to your truck or is it stock?
That's a tough one.........

 

[rzohr251]

Ive just got a superchips programmer, i usually leave it on tow mode which is like a 40hp gain, but thats really it. I read somewhere that someone had a problem similar to mine and his turned out to be the turbo blade rubbing on something in the housing causing the grinding noise.

 

[LBZ]

Could be. Good place to check I suppose. Pull the inlet off of the turbo and look to see if the impeller is hitting the housing, scratches in the housing, and excessive endplay in the turbo shaft.

How many miles on the truck?

 

[Brayden]

The early transmissions were prone to the T5 thrust bearing failure. You may want to check the pan for debris. It can really tear a trans up if the bearings go through the planetaries.

Brayden