Sounds Like Crap

[03Sierra2500FD434]

I have an 03 GMC 2500HD with a 6.0L and a 4L80E (Obviously). 98,000 miles. At idle there is a low knocking sound coming from the rear of the motor / front of the tranny. When I put the hammer down and the rpms get around 5000 there is a loud pinning / knocking noise that comes from the front of the truck. Almost sounds like a spun bearing, wether you could hear that from the cab or not, thats the best way I can describe it. I checked the flywheel, wasnt cracked. I am wondering if its a common occurence to destroy the torque converters in these trucks, or if I'm way off the mark. What could this noise be. The idle knocking sounds strongest directly under the bell housing. Anyone had any similar problems? If so, what remedied it?

 

Thanks in Advance.

[sillyazz]

I have an 03 GMC 2500HD with a 6.0L and a 4L80E (Obviously). 98,000 miles. At idle there is a low knocking sound coming from the rear of the motor / front of the tranny. When I put the hammer down and the rpms get around 5000 there is a loud pinning / knocking noise that comes from the front of the truck. Almost sounds like a spun bearing, wether you could hear that from the cab or not, thats the best way I can describe it. I checked the flywheel, wasnt cracked. I am wondering if its a common occurence to destroy the torque converters in these trucks, or if I'm way off the mark. What could this noise be. The idle knocking sounds strongest directly under the bell housing. Anyone had any similar problems? If so, what remedied it?

 

Thanks in Advance.

Did you pull the transmission out to check the flex plate ?

Sounds like possibly cracked or broken flex plate or loose torque converter bolts you also might be right on the inside of the torque converter coming apart.

[03Sierra2500FD434]

I have an 03 GMC 2500HD with a 6.0L and a 4L80E (Obviously). 98,000 miles. At idle there is a low knocking sound coming from the rear of the motor / front of the tranny. When I put the hammer down and the rpms get around 5000 there is a loud pinning / knocking noise that comes from the front of the truck. Almost sounds like a spun bearing, wether you could hear that from the cab or not, thats the best way I can describe it. I checked the flywheel, wasnt cracked. I am wondering if its a common occurence to destroy the torque converters in these trucks, or if I'm way off the mark. What could this noise be. The idle knocking sounds strongest directly under the bell housing. Anyone had any similar problems? If so, what remedied it?

 

Thanks in Advance.

Did you pull the transmission out to check the flex plate ?

Sounds like possibly cracked or broken flex plate or loose torque converter bolts you also might be right on the inside of the torque converter coming apart.

 

 

Yes, I did check the flex plate, no broken welds / cracks / loose bolts. I was hoping it was the flex plate as they are cheaper than a torque converter but everything seemed to be okay.