Rookie 5r55s rebuild fail

[StangsandMavs]

I've done a few AODEs, but this was my first (and maybe last) 5r55s (06).

Transmission whined a bit, but worked fine and shifted well, prior to the OD sprag failing (150k miles). There wasn't a lot of debris, but it did get the surface of the OD Planet gear.

On teardown, everything looked new... frictions, bands... no heated spots. The only thing bad was the fluid and pump flow control valve, which had a step.

I got the complete rebuild kit, replacement bands, servos, and OD planet gear, OD Sprag, and Transgo Kit.

After the rebuild, I can't get 2nd and 5th. Got a 0735 and 0775 codes.. I checked to make sure nothing happened to the band... it was in tact and it was adjusted fine. I pulled the OD servo cap off and noticed that there was no fluid between the servo and the cap (???). I pulled the pan to make sure nothing blew up and everything seemed in tact, though I did retorque the valve body which I guess "settled". I replaced the solenoid pack while I was in there.

No change. The OD light flashes within 1/2 mile of driving. 2nd gear catches for a brief moment on light acceleration... not at all if I put it manually in 2nd... and there is no 5th gear heading down a hill at 60MPH.

So, I'm guessing that there is something that I fudged up or missed in the valve body or with the Transgo kit? Where should I look or am I missing something?

Thanks

 

[transman304]

Did you have bushings put in the servo bores by chance?

Or maybe a broken OD servo spring

 

[StangsandMavs]

Did you have bushings put in the servo bores by chance?

Thank you for the response.

There weren't any of the flare issues with the transmission prior to it failing and the band looked new... but knowing that this was an issue, I did look into it. Since the price of the tooling was prohibitive, I used a machined/o-ring version of the servo instead of boring them out. I checked the diameter of the new servo pin with the old one and did notice it was 0.001 smaller... but I would still suspect that *some* fluid would find its way between the cap and servo after being driven for 10 miles or so, even if the pressure couldn't build enough to engage it.

 

[StangsandMavs]

Did you have bushings put in the servo bores by chance?

Or maybe a broken OD servo spring
View attachment 330964

I missed the second part of this post, earlier...

And that MIGHT be exactly the answer. Kind of.

The Transgo kit has a green spring and 2 yellow springs... exactly in that location. I think my eyeballs are going south, but I got the larger springs switched! That would indeed be a rookie mistake if that is the cause... I'll try to get it back together and hope that it works.

Edit... got it back together and no change. I'm glad I found this mistake but I guess that would have been too easy.

 

[StangsandMavs]

I went ahead and bought the Rotunda"air test" plate as well as a Sonnax vacuum test kit.

On the Air Test, the clutches seem to engage fine. I'm not sure what to look for on the Servo tests, I did re-install the OD servo... I didn't see anything wrong with it. While I had the adjustment loose, I tried the air test and could see the band respond to the air pressure.

I vacuum tested the valve body according to the Sonnax guide and everything seemed consistent. I tried using the vacuum tester on the transmission case, but didn't have luck in getting a seal with the provided plexiglass block, which was just a bit too small to seal the cavity they discuss testing.

While I still have this apart (pan & valve body) and have this new test equipment... anything I should absolutely be checking?

Thanks, again.

 

[JK080]

Check this valve, I know if the retaining plug is too far in or in backwards it will cause the OD servo not to apply.

 

[StangsandMavs]

Thank you for the advice.

I checked it... saw that it was the one that is pretty deeply recessed in the bore. The end plug did stick a bit when I tried to pull it out with a bolt, but disassembled it and reassembled it. Looks to be in the same spot.

 

[StangsandMavs]

Check this valve, I know if the retaining plug is too far in or in backwards it will cause the OD servo not to apply.

View attachment 331406

While I see that there is a bleed/drain in the OD servo bore between the servo and the cap... am I correct in thinking that there should be some evidence of residual fluid in there when it is pulled apart? I can't remember how much (if any) fluid was there when I originally disassembled it. That's why I figured it was a plumbing issue in the valve body.

 

[transman304]

There is fluid on both sides of servo for apply and release.
Did the solenoid pack get replaced?

 

[StangsandMavs]

There is fluid on both sides of servo for apply and release.
Did the solenoid pack get replaced?

Thank you for that.

I didn't have this problem prior to the rebuild... but I did get a new solenoid pack and swapped it out. There there wasn't any difference in driving it... OD light started flashing within a half mile of the house... and still wasn't any fluid between the servo and cap. Although I didn't drive it very far (maybe 3 miles), the servo still had the trans assembly lube that looked like it was undisturbed (no fluid mixed in).

Appreciate your time.

 

[StangsandMavs]

Did you have bushings put in the servo bores by chance?

Or maybe a broken OD servo spring
View attachment 330964

Check this valve, I know if the retaining plug is too far in or in backwards it will cause the OD servo not to apply.

View attachment 331406

Thanks to both of you for steering me in the correct direction.

I got it.

I went over the entire valve body again... just double checking everything. Remember that I earlier posted that I had switched the yellow and green spring? Well, when I did that, I distorted/flared the yellow spring. It was tight in the Servo Control valve... the spring "dragged".

I ended up going back to the stock spring, just to make sure that was not the problem. Although I re-cleaned and double checked everything in the valve body and did those air tests on the case, I don't think I did anything else that would have made any changes to the way the car would drive.

I put it back together this afternoon and 2nd gear was engaging about 50 ft from the driveway. Drove it about 10 miles and it felt good all the way around. The vacuum test didn't catch the bad spring because the valve was closed.

So, thanks again. I'm going to have a very happy daughter when I give her the news. It was a "rookie" mistake, all along.