4r55e problems after rebuild

[toy720]

4r55e problems after rebuild

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hey anyone with some input i would appreciate it
ok here is the deal i have a 95 exp 4x4 i rebuilt the tranny about
4 months ago and not had any problems with it now all of the sudden
it seems like it misses second totally or if you put in manual 2 it will slip
if you let of the gas a little it will go ahead and hit 3rd od light is flashing
tried to reset but no luck also double checked tr switch and All seems good there. any ideas would be great i really dont think it is internal i feel it is more electrical. surely it has not burned up already.

thanks
brad

 

[Glacier991]

I'd start by checking the line pressure..... While there are other possibles the valve body loooms large (which is good news). The other possible in the intermediate band...out of adjustment (might wannt recheck that, it's easy enough to do) your intermediate servo piston could have developed a problem, or the band and/or drum could have gotten glazed. Let's start with the VB... and pressure will tell us a lot.

 

[toy720]

ok i dont have a guage for that i dont think i do have a fuel pressure gauge that
is capable of reading up to 100 psi i might have some fittings that i might be able to make work but by theory if the tranny works fine in the other gears then there should
be plenty of pressure to operate 2nd gear right??? im thinking about the band situation
if you remember i decided not to replace them during rebuild might have been a mistake? servos replaced also i replaced the tranny range sensor but i have a feeling it could be this as well but im told there is no way to test this sensor?? any advice i will
pull the pan and look at valve body and solenoids and check them as well is this a possibility shift solenoids?
thanks brad

 

[Glacier991]

Well let's say you have good line pressure in 1st. You shift to 2nd and you tie into a major hemhorrage of fluid somewhere.... pressure is low as a result. Just because you have pressure to operate ONE gear does not mean that in another gear you will have similar pressure necessarily. I am doubting a shift solenoid. I'd consider getting my hands on a pressure gauge...PM me, maybe we can work something out.

 

[toy720]

ok that makes sense where would be a place to get one, i would like to have one
so i will have one for the next time what about the tr sensor or valvebody i know the
tr sensor can cause a whole book of problems ok lets look at this you start in first and
you should shift to 2nd at 10-15 mph or so but it will rev to 30 unless you let off the gas a little then it either skips 2nd and goes to third or it hits 2nd and then 3rd quickly
but if your going 40 mph at a coast and drop it in manual 2 there is no engine braking
nothing just like it is slipping same as if you started in 2nd nothing hardly at all now im
thinking band????

 

[Glacier991]

well it is certainly possibly or even likely a band issue, but is it because there is no apply pressure or is it because the band is glazed? You can check pressure without taking anything out. Checking the band is a tear down. Do the easy diagnostics first is my motto.

 

[toy720]

4r55e trouble after rebuild

ok i now have a better desciption of symptoms what happens is first
is fine but it will go to about 3200 rpm before shifting into second but it will
go into second and drive fine you can make it shift earlier by letting off the gas a bit third is fine 4th good tc lockup good . but this is strange
when putting it in manual 2 it acxts like it is slipping or searching to hang in gear also no engine braking when putting in manual 2 while driving everything
else good. any ideas i would appreciate it.

thanks brad

 

[toy720]

bump

 

[toy720]

in case anyone was wandering the intermediate locknut backed out and the band was not functioning anyway readjusted and no more problems
thanks for the help
brad

 

[Glacier991]

Thanks for posting what you found. It is very helpful. Explains the lack of engine braking too. Anyway glad you got it figured out and fixed!!