5r55e rebuilt but having problems going into drive

[EricB123]

So I pulled the transmission and tore it down again. The sprag seemed to be failing to lock. The OD band was a bit burnt and the OD drum was scarred.

I did the following:

• Replaced the OD drum and OD band
  
• I had a used planetary that came with the OD drum but the sprag race was less worn on the original so I kept it.
• Replaced the sprag and it was grabbing properly and in the right direction
• Replaced the torque converter with a remanufactured TC
• Replaced valve body assembly with rebuilt VB

Put everything back together and the problem didn't change at all. Still does not want to engage in D very easily. It will if I go from 2->D. However it still slips and stutters when trying to take off from D.

I'm at my wits end. Could it be a bad pump? OD band tension? I'm ready to trash it.

 

[transman304]

Was the DTR (Digital Transmission Range Sensor) replaced at the time of rebuild? Or adjusted correctly?

 

[EricB123]

Thanks. It's literately driving me crazy. It's an interesting suggestion. No, I didn't do anything with that. In fact I had assumed it was mostly a simple manual sensor for neutral that would be reliable. I read up on it and I'll take a closer look. That would be way too easy though.

 

[EricB123]

Well I thought it might have been the DTR because on one setting it appeared the CLOSED condition was actually open. Replacing the DTR and adjusting it didn't work though. I guess at this point I have to decide to double down and take it to a shop or swap out the full transmission. I can't seem to isolate the problem with it going in and out of drive. The engagement into D is better and it fooled me for a while that it was fixed, but after a few miles it started acting up again.

 

[EricB123]

Here's an update. I was able to get a 5r44e and swap it out for the 5r55e. I used the same pump assembly from the transmission that was giving me trouble (5r55e) and this 5r44e is working great. I know the planetary gear is different, but in general it's working and shifting fine. So the problem is definitely isolated to just the 5r55e transmission and apparently not associated with the pump either.

Since like 75% of it is new or replaced, I'm not sure what other things to investigate on it. With the manufactured torque convertor the line pressure was more stable but it still fails to engage or engages slowly going into D and it still would shudder at speeds randomly.

Anyone have any ideas on it?