Astro Van Transmission Problem

[Astrovandan]

The trasmission of my 1997 4.3L (95,000 miles) has frequently begun to slam into 2nd gear after traveling at highways speeds for a while. After traveling for approximately 30 minutes or longer and then exiting onto secondary roads the transmission will not shift from 1st to 2nd smoothly. During this and at all other times it shifts fine between all the other gears. Also around town it shifts fine between 1st and 2nd gear.

This has been happening with growing regulatity for about a year. Once the gear slam occurs the Service Engine Soon light comes on. My local garage reports the code in the computer indicates that the autoshift at the right RPMs is not functioning and the manual transmission shift is having to kick in. Before I take the van to a transmission shop I wish to inquire if anyone else has experienced this problem and has any advice.

I would truly appreciate any information that anyone can provide.

[ontheriver]

When you shut the van off and turn it back on, does the problem go away? I had the same problem on my '97 Astro Van. It was the Lock-Up Torque convertor valve. My transmission guy said that when the fluid gets warm and you travel at highway speeds the fluid seeps by the valve causing slipping os the lock-up torque convertor. This puts the computer in "limp mode" and applies all throttle pressure to shifts. The repair bill to have mine fixed was under $300. The pan and valve body have to be removed. Make sure you get an "updated" part. The originals were too small.

[trannyman52]

the tcc regulator valve is the problem ,, the valve is not tempered enough and wears out ,,,,,, should also see fault code 1870

repair kit made by sonnax should solve the problem

[skflaash]

Yes I to at 70K on my '97 Astro experienced hard shifting only when warm. Shut it down, and all was well for a short time, It seems that slipping was occuring and full system pressure was being applied,thus creating harsh shifts.

After a few trips to the dealer, they finally admitted this was a know problem , amazing!!??

Fix was a re-man valve body replacement, under extended warranty , fortunately.

[big rorange]

Do other year-models have this problem too? I have a year 2000 Astro with around 98K miles. Started having the "hard shifting" problem at around 70K, and it has become progressively worse over the last year. When I come to a quick stop at a traffic light, after the car is completely stopped, it makes a hard shift and I look behind me to see if someone rear-ended me. It also shifts hard from first to second, mostly when I'm driving very lightly. (doesn't seem to happen when I "step on it") 2 trips to the dealer and they still won't admit a problem. Charged me $85 to re-pack some grease on a "yoke", but I'm still having the problem. I have 2,000 miles left on an extended warranty. Trying to get this fixed before warranty is up. Does anyone have any suggestions?