I have a 2007 silverado 2500 hd with a 6.0 engine and 4l80e trans. I just got the truck used and has had this problem when i got it. When the truck gets warmed up and i put it in reverse it tries to choke the engine down. It acts like the torque converter is locking up. Acts just like letting out on the clutch on a straight drive without giving it any gas . If it does choke down i can restart the engine and put it in reverse and it will sit and idle just fine then. I have a friend who works at the chevy dealer and he replaced the torque converter, filter and fluid . Now its better in reverse but still does it most of the time just not as bad. Pulling off in drive even feel better than it did. I can drive the truck now and stop and put it in reverse and it may act like its choking down one time then next time idle just fine. I am leaning toward something sticking in the valve body. Thanks for any help.

 

Run the codes to see if there is an electrical problem. If not, center section bolt might be loose.

Allan

 

My buddy ran the codes and drove it with the scanner hooked to it and said it threw a over temp code on the trans because of the tc locking up. Thats all it had.

 

I would next drop the pan and valve body. Check to see if that low reverse check ball has came thru the separator plate and check the center support bolt to make sure is hasn't broken off or loosened.


Allan