ive got a 92 chevy 2500 with 6.5 and 4l80e. was told it has about 100,000 on rebuild it shifts fine through all gears unless im going wot then it seems to get hung in the gears a bit it shifts fine in reverse till it gets warm. then I get a pretty bad shake. Ive checked the trans fluid and its full doesn't smell burned the rear mount on the transmission was pretty loose and I tightend it up. still didn't help any the shake in reverse only happens during running temp. also it happens right off idle once I get going in reverse it starts to quit.

 

Wonder of your engine mounts are worn enough that the engine rocks over far enough to restrict either the fuel supply or return line?

 

the motor never acts like its starving for fuel? the transmission does kick hard to the drivers side when its in reverse.im just wondering if theres something loose that needs tightened up it does sound like theres a mount loose somewhere.

 

is there anyway I can check to see if my motor mounts are bad?

 

Use the running engine-have a helper shift from park to reverse to drive while holding the brakes and see if it rocks excessively-stand in a safe location while watching.