5R55S Delayed Engagement

[Grant S]

I recently purchased a wrecked 2005 Explorer with a fairly newly rebuilt transmission to swap into a 2005 Mountaineer I also just recently purchased. The Mountaineer would only move in 3rd gear, the previous owner had tried swapping out the solenoid pack trying to fix it with no success. Unfortunately the Explorer was not drive-able when I bought it so it was a gamble on the tranny being good, although I was shown paperwork for the transmission rebuild within the last 20K miles. So I swapped that tranny into the Mountaineer over the last couple of days (both had the exact same code on the I.D. plate) but now I have run into a problem I am hoping someone on here has seen before. I changed the filter and set the fluid level to a quick drip/not quite a stream coming out when running in park. The issue I am having is the engine must be rev'd up to 1500 rpm, and then its takes 1-2 seconds before the transmission will engage in any gear (RD321). I have not taken it out onto the road yet (just gone up and down driveway) to see if it will shift through the gears or not. There is no check engine light or flashing O/D light. Any ideas?

 

[transman304]

Sounds like a low fluid issue. Was trans up to temp when you checked? There are 2 filters for this transmission. One has a 2.4" pick up and the other is 1.4".

 

[Grant S]

Trans was up to temp roughly, I did not have a temp probe on it but it was warm to the touch but not hot. The filter I put on was just a Wix from Oriellys, didn't really pay much attention to see if it was the exact same as the one I took out or not, guess I'll be dropping the pan tomorrow. Gives me something to look for anyway, thanks!

 

[imp]

@Grant S
Stick a pressure gauge on that baby. Odds are one of them Pressure Control Solenoids is mechanically stuck, a condition the PCM cannot easily (or at all) detect. In the case of all the solenoids, PCM is aware of current draw by their coils, or lack of it. Mechanical binding of a solenoid plunger is another animal. imp

 

[Grant S]

@Grant S
Stick a pressure gauge on that baby. Odds are one of them Pressure Control Solenoids is mechanically stuck, a condition the PCM cannot easily (or at all) detect. In the case of all the solenoids, PCM is aware of current draw by their coils, or lack of it. Mechanical binding of a solenoid plunger is another animal. imp

Turns out when I installed the filter one of the seals got pinched so it was not fully seated fixed that and everything seems to be functioning fine now. Just out of curiosity, where would a pressure gauge be installed? One of the cooler line ports?

 

[imp]

Turns out when I installed the filter one of the seals got pinched so it was not fully seated fixed that and everything seems to be functioning fine now. Just out of curiosity, where would a pressure gauge be installed? One of the cooler line ports?

@Grant S
Not cooling line, it operates at substantially lower pressure than the general hydraulic system, just high enough to push maybe a gallon per minute through the cooler. I believe usually the pressure port is located on the left hand side of the case, look for a threaded-in pipe plug. 5R55S I'm not dead certain. imp