1999 Chevy Suburban V8 Two Wheel Drive Automatic 142000 miles
My transmission died and wouldn't shift into 2nd or reverse, etc, etc. I had it worked on/rebuilt. Many things were replaced - gears, solenoids a couple of times, a big round drum things (okay, I'm not the mechanic obviously), valves cleaned so the balls move, piston/springs replaced, new fluid and filter (he said there was a filter that was too small and he put in a longer truck filter). It was taken apart and put back together a few times because he can't figure out what is wrong with it now. Rear works fine. 1st works fine. 2nd has a small hiccup but works. 3rd and overdrive are hit or miss and requires heavy RPMs to get it to change and generally hard, sometimes very hard. I also heard something that sounded like air brakes releasing. No, I am not driving it other than to get it home after the mechanic apologized profusely and didn't charge anything, though I did give him some anyway for the work he did do as far as replacing parts.
Here are description of possible causes for the condition.
Slipping, Rough Or No 3-4 Shift
Check oil pump assembly faces not flat or pump cover retainer and ball assembly omitted or damaged. Valve body assembly 2-3 shift train, accumulator valve, 1-2 shift valve or 3-2 control valve stuck. Manual valve link bent or damaged. Spacer plate or gaskets incorrect, damaged or not positioned properly. Defective 2-4 servo assembly.
Incorrect band apply pin. Servo seals missing or damaged. Porosity in pistons, cover or case. Plugged or missing orifice cup plug. Case 3rd accumulator retainer and ball assembly leaking. Porosity in 3-4 accumulator piston or bore. 3-4 accumulator piston seal or seal grooves damaged. Restricted oil passage. Defective input housing assembly. Forward or 3-4 clutch plates worn, or excessive plate travel.
Forward or 3-4 piston seals damaged. Porosity in 3-4 clutch housing or piston. 3-4 piston check ball
stuck, damaged or not sealing. Restricted apply passages. Forward clutch piston retainer and ball
assembly not seating. 2-4 band worn or not positioned properly. Sealing balls loose or missing.