Need some help from the transmission people as I work through some things.

2005 V10 limited.4r100. 135,000 miles. Super clean. Runs strong.

Had fluid leak up front while towing, Overheated trans. Could have gone the converter pump seal and tried but I opted to do the rebuild.

Since rebuild, been working through some shifting issues. Transmission will shift perfectly…but every so often it will slip badly as it’s shifting…and either just drift into the next gear sloppily or shift into the next gear really hard.

Went back. They found a retainer ring in the valve body had broken. Fixed that. Similar shift issues remained.

Went back. Worked on a valve they felt was sticking in the accumulator VB. Similar issues remain.

Just sent back in and he’s installing a from FORD replacement solenoid pack.

Transmission shop comes through primary shop who is highly reputable and established here. Transmission shop owner very close with our shop owner and is definitely taking it seriously.

I THINK he’s working methodically through items as he diagnoses what’s happening, and feel like they’ve all been very responsive and willing to keep going with it….so I still have trust here.

I did ask about the initial broken retainer ring from the first return…and for that they removed and reopened the entire unit to check for any metal and inspected all the discs/clutches at that time and everything else was perfect at that time.

The symptoms, because they are not consistently happening and are only intermittent he feels exist in a problem in the controls : main Valve body, accumulator VB and the solenoid. So he’s working on that.

Can someone explain the function of these 3 components…the main valve body, accumulator and the solenoid?

with an intermittent sloppy shift like this…I feel like he’s working in the right area…in a methodical way as opposed to just swapping stuff….but could use some insight here.

 

There are multiple solenoids involved with shifting.

First, there are two shift solenoids that determine what gear the trans is in. These are on/off solenoids. As they are turned on or off they move valves in the main valve body. These valves control the flow of ATF to the clutches. As the clutches begin to fill, the valves in the accumulator body modulate the pressure to the clutch, which controls the shift feel.

There is also an electronic pressure control (EPC) solenoid. This controls main line pressure. If it is too low, line pressure is too low, and the shifts will get long and slippery.

There is also a torque converter clutch control (TCCC) solenoid. It controls the lockup clutch inside the torque converter. The converter clutch is slipped a controlled amount during many shifts. If it is having a problem it could allow the converter clutch to release during the shift, which would feel like a long shift.

Has anyone read the codes? That may provide a much needed clue.

 

Thanks for this response!

My understanding is he is replacing what’s commonly called the “solenoid pack”. Are the EPC and/or the Tccc solenoids part of that component or separate? I will inquire on both but want to know what I am asking.

This is an intermittent problem that l would say is primarily felt in the 1-2 shift.

As for codes, if you mean like readable OBD codes…I don’t believe there have been any as we’ve discussed this….but if you are suggesting there’s some embedded data that’s readable beyond that please let me know.

Thanks again.

 

OK I answered first part watching
YouTube video. I see They’re all onboard that solenoid pack. He’s replacing that with new from Ford, this is all under warranty so I’m inclined to just let him swap that out and see as opposed to pin testing.

Suppose will see when it comes back. I would imagine since he’s been pretty thorough each time that he’ll check all the movements on the valve body and accumulator while it’s open…but do you more generally agree that it seems likely a problem in the controls (solenoid, VB, accumulator)? Which is where he’s focuses as opposed to an issue inside with clutch discs etc?

thanks again

 

I can't tell where the problem lies. Running the codes would provide a lot of information.

 

yes I’ll ask him that…but is it straight codes through like an obd scanner? I have checked that and there’s no codes currently….

or is there more data they can read beyond a code scanner that is useful?

 

it has to be a Ford Protocol Scanner.

the el cheapo stuff off the shelf, can't read Ford codes