4L60E no reverse, no second

[Brian Robichaud]

I was driving home tonight, in the rain with the second gear start on. While pulling away from a stop light the car suddenly jerked and jumped forward, as if it had downshifted to first. I let off the gas an coast to the next red light, a block away. I turn off the second gear start, and the car starts off fine in first gear, but wont shift to second. At about 4500rpms I let off the gas suddenly and then it shifts, but the engine bogs down like it had skipped to 3rd. I give it a little more gas trying to accelerate, when the transmission tries to downshift but there was nothing there. I let off the gas and it goes back to 3rd. After I get home I realized reverse is gone!! The fluid level checks out fine, I just had the trans flushed, with new filter, two months ago. I've read post about the code 1870, but I have had no engine lights, or any problems at all, before tonight. Anyone know what causes this? Can the transmission be repaired? I'm looking for a cheap used trans just to get the car running this weekend. But would like to have the original trans properly fixed for later use. Right now I just have to get my car going ASAP!
1998 Camaro 3.8 95,000 miles

[redbird00]

ok

[ZR-1 Freak]

Solenoids

[Big Bad James]

Originally posted by redbird00:
ok

That was, by far, the most contructive post I've ever seen. WTG FGT.

Being that the 4L60E is a computer-controlled transmission, it could be anything from the PCM to, as ZR-1 Freak said, a simple solenoid.

Looks like someone will be making a visit to GM.

[Brian Robichaud]

This morning I had a friend who manages a garage, check on alldata, and he found a GM service bulletin describing the exact problem that I'm having, no reverse, 2nd, or 4th. According to the service bulletin the problem is caused by a broken sun gear. I’ve talked to several other mechanics who all suggest that’s its probably the sun gear, or maybe a solenoid. My friend is letting me use his shop this weekend, so I'll have him scan the computer first, to rule out electrical problems. I already have a used trans lined up for a quick swap, until I can fix and beef up the original trans. These things always happen at the worst possible times, but at least this will give me the chance to finally fix that leaking rear main seal.