Hard Shifting

[racing99]

I have a 1998 gmc 5.7 auto, always from a stop from 1st to 2nd gear it bangs hard but not from 2nd to 3rd or to 4th, doesnt matter if the truck runs for awhile or not, sometimes it shifts harder then others but it snaps the head back good at times, im scared one of these times somethings going to break, ive changed the tranny filter and had it flushed nothing appeard wrong in oil pan or oil..............any ideas

[rodram]

this transmission needs to go to a shop for diagnosis .. these symptoms you describe can be caused by a number of issues... usually all related one way or another to the transmission just getting tired and worn out....

 

if this is the original transmission, it may be time for a total rebuild ... these 4L60E transmissions do have a finite life time with an average service of 130,000 to 140,000 miles ... if you are over this mileage on the transmission then any small patch repairs on the transmission are just going to get you by for a little longer until it totally fails.