trans does not go in gear when cold out

[mtrhead79]

i have a 01 astro awd that when its cold will not go in gear unless it idels for about 5 mins then the rest of the day is good shifts fine. started doing this since it got cold out. is this what i think it needs rebuild. oh van has 127,000 miles on it. thanks for any help

[Smiliesafari]

Hey John. If it shifts fine after it warms for a bit, it's not likely it needs a rebuild. It sounds like fluid is draining from the torque converter and it's taking some time to refill. After the trans warms up check the fluid level. Then first thing in the morning before you warm it up check it again. It should show a higher fluid level.

[mtrhead79]

i will check the levels. had it out yesterday. would not go in gear at 1st waited about 4 or 5 min. then went in gear. i drove it on a 100 mile round trip to south nj. went to a couple jys looking for parts for my wagon. shifted great the whole time.

[LiftedAWDAstro]

Never had one apart but is there an anti-drainback valve in the filter itself?

[mtrhead79]

the filter looks to me like a big straw with a filter element at the bottom. i had replaced it about 2 months ago. went out today and only waited about 1 min then went into gear but it is not that cold today. i am going to use it later today will check the level then compare it to what it is in the morning. i was thinking of getting rid of it before this and get another astro in better shape with lower mileage . i guess i waited to long.

[Smiliesafari]

There's no anti drain back valve that I know of. I had the same problem with an 87 Monte Carlo. I ask several professional tranny builders and the only answer I got that made any sense was too much clearance in the front pump bushing. I'm not even sure that's the cause. If anyone else has some info on this I'd like to hear it.

[lockdoc]

It may be just as simple as adding fluid. You haven't mentioned if you checked it or not. It might never have been filled properly since the filter was replaced a couple months ago. In case you don't know, check the fluid while the van is running and at operating temp.

[mtrhead79]

fluid is filled. i did check it when hot. i also checked in morning before i start it and it is overfilled then but once up and running around the level is good

[Mr_Roboto]

It could be a boost valve problem as well. These transmissions are known for it due to bore wear in the pump. There is an o-ringed boost valve for the 4L60Es out there. http://www.race-mart.com/TCI-TCI-374420.html Could also be a pump inlet pressure issue. Any high pitched noise at all? If so that's probably pump cavitation. Did you flush all the fluid? If so be sure the right kind was put back in. My van made cavitation noises at idle until I let it warm up when I was running hy-tran (drag racer's trick) but with normal ATF I don't really see this being an issue. Easiest thing to do is probably hook a gauge up to it then check it out that way.

ED:Call your local GM dealership and see if there's a box flash they can do for you as well. My buddy had an S10 and it would delay going in to reverse. Turns out there was a TSB for it and he got a free flash that fixed the issue.

[mtrhead79]

well trans is no longer a problem for me. i sold it to a friend. told him about problem then let him have van for 3 days while i was away, that way he could see the problem for himself. when i came home he said he wanted it so its been gone for about a couple weeks. now looking for another van. i think i want to get a shorty. i really liked my 92 no window cargo.