trans wont shift from 1st to 2nd or 3rd to 4th

[jayreb250]

HEY GUYS, I am sorry I haven't been back sooner my other car blew a power steering hose so I had to fix that and today got back on the transmission.
I checked the servo's and the springs are in the right location,but the covers are both Ab covers and the servo's themself look exactly the same. The seal around the intermediate servo has a piece chipped off of it so that probally is atleast part of the problem. I was noticeing though, when I looked at the fluid that drained out when I removed the servo's that there is some metal flakes in the fluid. I THINK I KNOW WHERE IT IS COMING FROM BUT I WANTED TO SEE WHAT YOU THINK( BEFORE I TELL YOU MY OPINION, JUST TO SEE IF WE ARE THE SAME)
the biggest piece is real thin and kinda looks like it has little B B sized indentions in it. All the pieces are real thin and flat looking except the B B indentions, most are about the size of these letter o's oooooo or smaller the big one is about the size of a both DD's.

 

[Brain]

AB covers on both means it's pretty hard to mix them up ; )
I've only had the opportunity to rip apart an A4LD and a 5R55E, so I wasn't sure which servo sizes came in the 4R55E (like yours). Metalic contamination does rip up rubber seals pretty fast. Whick seal on the intermediate servo was chipped (servo/case, sevo/cover, or cover/case)?

Is the metal contamination leftover from the previous problem, or did you wash the case out really well? Chewed up springs or spring posts? That's my guess without a picture to look at...What's the material - steel, aluminum, bronze?

 

[jayreb250]

Servo seal to case. Is that seal supposed to be hard plastic fealing or is it supposed to be soft rubber?
as for the metal I cleaned the trans case pretty good and I cleaned all the parts, I supose that it could be left over maybe still inside the TC didn't clean that(I hope). I need to go look at it again to make sure but I think it was kinda bronze looking. I was thinking that it is coming from a damaged torque converter. the band that broke just lost the lug where it attaches to the case or the servo( can't remember which side broke) and stayed in place it did not appear to have done any other damage to anything.

 

[jayreb250]

the servo that has the chipped seal is the intermediate servo... so if its leaking it would cause it to not go into 2ND gear, or 4TH, or both. if 2nd why are we not getting 4th and if 4th why are we not getting 2nd?

 

[Brain]

The servo/case seal disengages the band, so that isn't the problem (with either gear)...The servo/cover seal is the one that applies the band, and if that was chipped/leaking it would have made more sense, as no intermediate band application would have not engaged 2nd.

Servos seals are soft/supple rubber when new, but get harder as they age (and possibly because they overheat due to their proximity to the HOT catalytic converter). When you removed the servos this last time, were the tops of the servos seated in the covers? This is what I was thinking was wrong - that they possibly weren't seating/sealing in the covers (as the servo/cover seal is the one that allows the band to apply).

 

[jayreb250]

I don't know for sure about the intermediate servo after I removed the snap ring I was tapping on the cover to get it lose and it popped out so not sure if it was sealed. the overdrive servo was in the cover when I removed it.
the servo's where not soft at all more like hard plastic.
I looked at the metal pieces again and I think it is aluminum it is kinda greyish not magnetic (small amount of steal very small amount).

 

[jayreb250]

I have to go out of town today should be back Sunday. if you come up with any ideas go ahead and post them if you want.

 

[jayreb250]

hey look at MEDIC1'S post thta is exactly how mine started out.

 

[jayreb250]

I am getting new servo's today, I am just grasping at straws but if the servos are hardened is it possable that they are not appling becuase of the hard seals. What else should I be looking at if its not the servo or the pump? If I reassembled the trans correctly and the only problem before the rebuild was 2nd, why would I not have 4th now along with 2nd?

 

[Brain]

It is possible that hardened servo seals won't seal properly and allow it to engage with as much force as is needed to apply the bands properly.

 

[jayreb250]

I installed the servos last night but did not test it yet I need to readjust the bands and test it today. Cross your fingers maybe it will work
:exporange :roll:

 

[jayreb250]

Hey I have some Knew news, it's kinda working sometimes!!
I replaced the servos and readjusted the bands and went for a drive.
It does not seem to want to go into or stay in driveI was shifting it through the gears to get the fluid circulated so I could make sure the fluid level was correct, but it does not always want to go into drive. I can sometimes get it in drive normally and it will shift out like its supposed to but when you slow down to a stop it will not go anymore. I can shift into 1st or 2nd and it will go into gear and I can then move it over to drive but it goes back to the old problem no 1-2 or 3-4. If I can trick it into drive without going to 1 or 2 then it will work again. there have been some hicups where it seems to go back and forth between 2&3rd then finally makes up its mind and shifts into 3rd and 4th. Also the overdrive will work when you cycle the button.
I know this is crazy sounding, but please don't give up on me YET!

 

[Brain]

OK...it sounds like all of the gears can be engaged, it is just a matter of getting them to engage/disengage at the right time. I think we can narrow this erratic behavior down to a couple of things:
1) bad sensors (either on/in the trans or the rest of the vehicle)
2) plugged/sticky valves in the valve body or solenoids
3) misadjusted shift cable

The first thing I would do is run a code scanner to see if any sensors have gone bad. Check out the bottom of this link (where 4R55E is listed):
http://www.usatransdoctor.com/DomesticFORDselectandAnswers.htm#4R44E

After that I'd have a friend help stand on the brakes so I could unhook the shifter cable at the transmission and shift it into gear by hand (makes sure the shift detent in the tranny isn't missed because of the column stops for the shift lever).

If it still was behaving badly, I'd probably have a couple of beers because I'd have to think about taking a tranny fluid bath (except now I have installed a drain plug) to be able to check/clean the valve body and solenoids.

Seriously, check the codes first...this erratic behavior stinks of a bad sensor someplace...

BTW, if you are thinking of getting a pressure guage, check this out (only $33):
http://www.etoolcart.com/index.asp?PageAction=VIEWPROD&ProdID=788

 

[jayreb250]

I have not been able to take to get codes read but have been doing it the ole fashioned way with a multimeter, I read through the trans manual again to see if I could find some info in there that might be helpful.
I don't have the book with me to tell you word for word but I found a thing in the dianostics section that says if you hav low or no pressure at the EPC solenoid that you would have no 1-2 or 3-4 and also some other stuff that I can't remember right now.
also there are a multitude of engine sensors and things that can have an effect on EPC pressure and operation, so I am going through and checking with my handy dandy multimeter those sensors and wiring. SO MAYBE, JUST MAYBE, I WILL TRACK THIS THING DOWN BEFORE NEXT CHRISTMAS.
Also I am trying to get a pressure gage so I can see what that tells us.

 

[Glacier991]

Brain's post is the best price I have ever seen on a pressure gauge! At that price every budding trans techie ought to own one!

 

[jayreb250]

This thing has a mind of its own!!! I have not really done anything that should have made it change, but it is acting a little different(better). It will shift into Drive with no problems now, but will sometimes feel like it has droped back into (N) while driving, I have to shift it into 2 or N and then back to D and it will ussually work again. It seems to work almost right now other than that, sometimes it feels like it shifts a little hard but other than that its O.K
I have been testing the MAF, TPS, IAC, CTS, and everything seems to be O.K which is kinda disappointing( I was hoping to find SOMETHING wrong). I called up my budy at the dealership and took it back to see if we could find something new with the computer.We got a code for DPFE which he says is the ford EGR sensor(should not be related), also we were able to look at the epc pressures.
at idle in P we got 28psi in R we got 50psi, N went back to 28psi, D went breifly to 68 psi then dropped to 30psi and the same with 2 and 1.
the trans temp was at 167 degrees. I have not gotten my trans gage yet still waiting for that, maybe some of this info will help point us in the right way until then.

 

[Glacier991]

Those pressures are in line for EPC, slightly low but not bad....this one IS curious... almost sounds Processor related... which I am the LAST to suspect.

 

[jayreb250]

so you think the EPC pressure is O.K. then.
How would we know if it is the processor which I am assuming by that you mean the computer? I am at my wits end with this one.

 

[Glacier991]

HOnestly short of finding one to substitute I have no idea.... this where the Ford Transmission tester would be nice. you can run the trannie unconnected from the computer....do the electronic shifts from the tester.... Wish you lived closer.

 

[Brain]

The wife's Escort has a DPFE that went bad and launched some codes ("check engine" light constantly illuminated, causing the wife to ask about it over and over). It is a differential pressure sensor (the DP part of the sensor name). I would go on ahead and replace that and then clear the codes from the CPU before I went any further with trying different things. A confused CPU because of a faulty sensor that you think is unrelated (but is still tied into the CPU) is just the sort of thing that the previous link was warning about. After that, I'd try a stall test and be certain what shifter positions are letting the slipping occur (something that can be done before you get the pressure gauge).