I have a 03 GMC 1500 and have a problem with my transmission slipping. When i put it in reverse then back into drive it slips as i am accelarating, i have been playing around with it a bit and it seems like it starts in third gear then as it slips it shifts down into the correct gear, it also seems to downshift slow. my question is is it the transmission or a module that would cause that.

 

time for a rebuild

 

Well i think i figured it out, i had strange thought of maybe the filter was plugged so i pulled the pan down and the filter had fallen down so someone put the wrong filter in so it wasnt picking up the oil. Strange, but it did fix it for now.

 

wow thats odd, good stuff