GoremanX
09-04-2006, 09:19
I've had many transmission failures in the past on other vehicles, but they've always been sudden and catastrophic, usually on a race track or drag strip. I've never had an automatic transmission fail slowly of old age before, so I'm not sure what to look for. But the 4L80E in my '98 K2500 6.5TD seems to be exhibiting signs of old age. Problem is, I don't know if these signs are really just typical of a 6.5TD-equipped truck. We haven't owned it all that long.
When the engine is still somewhat cold, trying to press the accelerator while in reverse produces some painful surging, like the torque convertor is grabbing/slipping suddenly and randomly. This does not happen at all while driving forward. I don't see how this can be a torque convertor problem since it doesn't do anything different from Drive to Reverse.
When the truck has been driven for more than 30 minutes, the shifts seem odd. The engine surges slightly between shifts, like the transmission is sitting between gears for a second or so. This is with very sedate acceleration. Flooring it from a dead stop gets me some very lively acceleration, but then the transmission misses its shift at 3500 rpm for about 1 second before banging into 2nd really hard.
I've checked the transmission fluid and it looks brand new and perfectly clean. The fluid level is right where it should be after the transmission's been warmed up and the truck's been driven around a while. There's no SES indicator lit up in the dash, and I'm pretty sure transmission or torque convertor slippage sets a code. But my 1993 Suburban gasser with the same transmission doesn't behave like this at all. Shifts are crisp and responsive, with no slippage or hesitation.
This is obviously the second transmission that's been installed in the pickup, it's painted all blue. All indications show that the truck did heavy service as a snow plow and a fifth-wheel hauler for its previous owner in Maine.
Is there any specific test I can do to check on the health of the transmission? I'd rather not have to pay a transmission tech to check it out if I don't have to.
Thanks,
When the engine is still somewhat cold, trying to press the accelerator while in reverse produces some painful surging, like the torque convertor is grabbing/slipping suddenly and randomly. This does not happen at all while driving forward. I don't see how this can be a torque convertor problem since it doesn't do anything different from Drive to Reverse.
When the truck has been driven for more than 30 minutes, the shifts seem odd. The engine surges slightly between shifts, like the transmission is sitting between gears for a second or so. This is with very sedate acceleration. Flooring it from a dead stop gets me some very lively acceleration, but then the transmission misses its shift at 3500 rpm for about 1 second before banging into 2nd really hard.
I've checked the transmission fluid and it looks brand new and perfectly clean. The fluid level is right where it should be after the transmission's been warmed up and the truck's been driven around a while. There's no SES indicator lit up in the dash, and I'm pretty sure transmission or torque convertor slippage sets a code. But my 1993 Suburban gasser with the same transmission doesn't behave like this at all. Shifts are crisp and responsive, with no slippage or hesitation.
This is obviously the second transmission that's been installed in the pickup, it's painted all blue. All indications show that the truck did heavy service as a snow plow and a fifth-wheel hauler for its previous owner in Maine.
Is there any specific test I can do to check on the health of the transmission? I'd rather not have to pay a transmission tech to check it out if I don't have to.
Thanks,