Transmission shifting hard and wining

I have heard I need a new pressure control solenoid installed and would like some confirmation before pulling everything a part. Here is what I know:

1. occurs only after the vehicle has been driven (30+ minutes maybe). Turning off and on does not help. Waiting overnight corrects the problem.
2. the wining sound is the same as sound low power steering makes - the sound is only present when the hard shifting occurs.
3. 120k.
4. No check engine light.
5. fluid and filter are less than 20k old.
6. fluid is clear, clean, and not burnt; smells the same as the stuff in the bottle.

I checked on parts and I'm ready to pull everything apart.

OK..2000 Montana...same transmision as mine, even if mine is older.. I also have this whining sound ...for years...and it matches the exact description you provide. I blame the pressure regulator for that sound....but I have no proof of that..and it has not gone worse over the years. However, I do not have the hard shift, so it might have no relation with the whining.....
Generally, hard shift is to blame on the accumulators, and they are accessible from the bottom, just remove the pan and the filter. One can overhaul them for a small price...check rockauto.com (check "rebuild kit"--2 needed 12$ each..that is not a costly error....) to have an idea.
Hadr shift used to be blamed on the modulator also but it has gone electronic past 1999...modulator no more listed.

I found the parts. Is the pressure regulator replaced from the bottom too? Located in or on the valve body?


AutoRock is a great source. Many thanks.

www.avigex.ca/xport/accu1223.jpg (1-2 and 2-3 accumulators)

.the pressure regulator is on the end of the transmission
3-4 and TCC accumulators are also hidden there.
www.avigex.ca/xport/4T60cutaway.jpg
www.avigex.ca/xport/4t60pumpassembly.jpg
....very cumbersome , shaft must be removed, ...
I wonder if you could have a transmission scan first to get some hint of the problem, if possible...
..trannyman52 is a good helper for transmissions...
http://www.automotiveforums.com/vbulletin/showthread.php?t=385506

'Shaft must be removed'

Would that be the drive shaft (driver's side)?

yes...:frown:
on which gears do you have a hard shift...if it applies to all, I would doubt the accumulators are involved....and then the pressure control solenoid you were mentioning at the beginning is a logical explanation....I do not have info on that...mine uses a throttle cable...

Gears 1, 2, and 3 for sure. 4 not soo much, as speed effects that.

I'm greatful for the help.

I've pulled axels before but don't remember the steps to getting the ball joint off/down. Any special steps I should follow?

Straight forward: jack car, remove tire , caliper and disk to get easier access, disconnect tie rod, remove retaining bolt, pry down on lower table....and I've done it without but disconnecting the sway bar will help a lot ..
ANd..better to get that shaft loosen and ready to be pulled out of the hub bearing before disconnecting the ball joint...

Great. A pry bar is key! I'd add removing the shaft nut before raising the vehical.

One more questions: On this image: www.avigex.ca/xport/4t60pumpassembly.jpg (http://www.avigex.ca/xport/4t60pumpassembly.jpg) is the PCS item 315?

You've been of great help!

I'd add removing the shaft nut before raising the vehical.
ABsolutely... :)
is the PCS item 315?
Negative....these (3) are shift or TCC solenoids...
THis is '93 4T60E graphics and pressure regulation is mechanical/vacuum.
http://www.thrashercharged.com/tech_htm/FAQ-4t65E.shtm

mine does the hard shifting/whining occasionally. and most times i can turn off the van, start it back up and will then shift like normal.

Wow ... this behaivor is turning out to be common. There has been no cure other than a cooldown for me.

All parts ordered and on the way. I'm now researching how to get the side cover off, or at least opened. I've read instructions for a car but not a van ... not major differences, but some. I found out the side cover gasket is $100. I hope it can be re-used. Any one know?