Long flared shifting

[the_mork]

I've been having some problems with long and flared shifts including occasionally not being able to get the car to upshift at all. When it does shift if I haven't backed off the gas the shift is quite violent. I think I've ruled out a couple of things. First I have placed a valve body from my old wrecked transmission into this one with a new IPT shift kit as well as having changed the fluid and filter. After that I have also pulled my tcu and inspected it. While it may still have damage I am certain that the caps have not leaked and there is no burned smell from the boad. At this point I am considering that it may be solenoids that are the problem but since I am less than fully versed in transmission operation I'm not sure exactly how solenoids affect shifting.

Can anyone provide some insight into further diagnosis or suggest a fix?

FWIW I think the transmission is physically fine because there is no slipping while it is in gear and there are no odd noises. An electrical/solenoid problem is also supported by the fact that occasionally the car will have a delayed response when shifting into reverse.

 

[rbwtrans]

Which gears are flaring? A missing or damaged o-ring (on the top of the valve body) will cause major issues like the ones that you are describing. The shift solenoids do sometimes cause issues, but usually just fail. A stuck or damaged EPC solenoid can cause low or high pressure and delayed shifts. I hope this helps - good luck.

 

[the_mork]

Thanks for replying. 2nd and 3rd have the most pronounced flare but I assume that OD does it too and it just isn't noticeable because of the conditions required for the car to shift into OD. I'm not sure how helpful this is but I should mention that the car tends to shift relatively well when cold and gets worse over time. After more than 100 miles or so getting off the highway and driving through town becomes kind of a pain due to the time spent between gears.

An interesting further symptom just happened to me yesterday in that I stopped at a stop sign and the car decided that it did not want to move any more. I could put it into gear and it would try to roll forward and then stop, and if I hit the gas it would pull a bit forward then try to move back as if it had a trans brake. After a few minutes it was suddenly happy again and allowed me to drive the 60 miles left to get home. This has only done this the one time and I'm not sure what is up with it.

When I get the chance I will be pulling apart the clutch pack to check for damage as the only time I have ever encountered something similar was with a damaged clutch pack that had melted together. Specifically I will be checking the piston seal and the piston valves. When I'm done with that I'll pull the pan and the valve body, retorque the VB, check the seals, and replace the solenoids with an extra set from a broken transmission.

I hesitate to think that it could be from a bad upper VB o-ring because the issue started before I did the shift kit so I had never pulled the VB. Some further background about this trans, when I pulled it out for the summer I had an issue where it would drive for 1/4 or so at a time then completely fall out of gear until I shut it off and let it sit for a while. Replacing the trans filter and fluid solved the problem completely but maybe this is related. Also the car sometimes takes a second or two to pop into reverse which also suggests to me that it could be electrically related. I have pulled the TCU and it looked and smelled fine.

Thanks for any further help you might be able to provide.

 

[ramsack]

going from 1st to 2nd is locking the band, going from 2nd to 3rd is unlocking the band, and going from 3rd to OD is locking the band again. sounds like the band is loose or worn out.