The other day I'm headin down the freeway, a slow van in front of me moves over. I get on it a bit, maybe too much, car down shifts into 2nd. It jumps and pulls like a BBB does, a split second later....BANG! Immediately back out of the gas, ease back in... nothing. Thought maybe I kicked it out of gear. Into Neutral, back to Drive....nothing. By now I'm slowin down a bit, try L2, nothing. There was zero resistance while coasting, no grinding, clanking, or any other banging. When I finally came to a stop, tried L1 and Reverse, nothing. Back at home, If I rev it to dang near 4k, it will move about as much as a really fat guy leaning on the car, still no unusual noises. Drain the fluid, looks normal. Pulled the trans/ converter this morning. Splines in the converter have about the same resistance as my old one. When I rotate the input shaft on the trans, it does turn the output shaft, but, I can also stop it from rotating by hand. Tore the trans all apart, the 2nd clutches in, have some burnt steels, and there was a mystery piece laying in the very bottom down where the park pin engages, I think it fell out of some where. As far as I can see, nothing is broken. Is it possible the clutches all went out but didn't leave debris, or the converter let loose internally? I'm at a loss.
I had similar experience. Harsh 1-2 shift then freewheeled. Not even reverse worked. I pulled trans and finally decided there was nothing wrong with it. With nothing to lose I cut converter apart. The spline hub stripped out of converter. So there was no driving of input shaft. Pump still worked
I can't remember the name of the gear, but it has 2 notches that engage torque converter. I lost all my gears when this failed. Transmission guy said it probably wasn't engaged all the way when we installed the torque converter.
Dennis.. refresh my memory.. TH 400?... if so, check the forward clutch hub or the intermediate sprag.. sprag outer race should only turn clockwise with the direct drum sitting on the table, sprag side up... and the forward clutch hub tends to break right at the splines. And a picture of the broken piece might be helpful. JW
Pump gear or converter. 75% probably pump. Easy fix if you can pull a trans, a few more steps and you can do the pump.
Jim, Th350. I figured out what the mystery piece is. When you start reassembly, it sits down in the deepest clutches, in a notch in the case. I couldn't find anything broke in the trans, so I reassembled it, installed my old converter, and gonna see what happens. I did not disassemble the pump, just removed it. I only have about 800 miles on this trans being rebuilt at a local shop.
So I just got it all back together with the old converter I had. Success! Wheels turn in gear on the jack stands, even riding the brake. So I get it all the way down, button it all up, finish filling up the fluid, and give it a better test. In reverse, hold the brake an give some gas, it'll spin tire, try Drive, L2, L1, all getting power to the wheels. Too late / dark to test drive now. I'll wait till its light out,.....just in case.
Went for a test drive, after a few easy miles. I get it up to about 25 mph and stab it, making it do the 2-1 downshift, lights up the tires. Cruise along at 55-60mph and floor it to get the 3-2 down shift, works as should, and puts down the power. I think it is safe to say the converter let loose.
