I rebuilt the E4OD 70k ago. Didn't replace the Torque Converter (TC) at that time. Now at 250k I put in a new TC and fixed a 2-3 bang. The bang is gone but there is no TC lock up at all. Returned the Ford TC installed the replacement Ford TC, same thing. So I took the trans completely apart. New steels and clutches to reduced all clutch clearances while I was in there. Checked the pump as well. put it back together, still no TC lock up. Shifting nice. The inside of this tranny is supper clean. I installed a TC lock up switch. With the ignition on I can hear the TC lockup solenoid click. But when I drive this click does not lock the TC.
How can I know if the TC is bad or if there is a stuck valve in the pump? The codes are not helpful 629. Swapped out the solenoid pack still no lock up.

 

It's rarely the torque converter. Often it is worn teflon seals on the input shaft or a stuck torque converter control valve.

 

It seams that I misdiagnosed the results of using the manual TC lock up switch. I read in one forum that the E4OD still has control of the lock up by controlling the the pressure of the transmission through the EPC solenoid. It supposedly will never lock in 1st. Other gears are pressure dependent. My original assessment of the lock up was by feel and at 35mph. Not a good method. (no tach) Today I played with the lock up switch on the turnpike and could definitely feel and hear the engine change while in 4th(OD). No CEL when I held the TC lock up switch on. The codes I read earlier today were 629 and 626. Also got one for the AC being on during the test and the EGR circuit.
Just can't figure out how the coast clutch is suddenly giving me issues. http://images.ford-trucks.com/forums...2/confused.gif

A piece of the puzzle I didn't previously explain was that the truck initially was parked because it just suddenly started to die without explanation in the early fall last year. The symptoms were identical to vapor lock due to the correct alignment of the planets that causes the fuel pump to have vapors during the seasonal evaporation changes made to fuels. Just waiting long enough and temperature changes in the fuel system will even out and it all works again. Releasing the fuel pressure from the fuel line relief valve into a rag while stuck at a red light also seams to work, but anyhow....

Got the truck home and parked. It then would not start. The fuel pressure was low, around 25psi so I changed the fuel pump. Got it to 45psi. Truck wouldn't start. Used a noid light to find no injection signal. After pulling and tugging on all sections of the wiring harness it turned out to be the hall effect sensor (cam shaft positioner). As part of assessing that hall effect problem I was using a breakout box on the PCM. (Hindsight:The Problem??Hummmm?)

Then with the new hall effect sensor the truck started right up. Didn't even drive it. I figured with that fixed and while the truck was there I should go ahead and do the transmission work. The Sonnax accumulator modifications and the Transgo shift kits have been great for the last 80k. The Transgo kit boosted tranny pressure and firmed up the TC lockup. But I wanted to take out the two shims causing my 2-3 bang. (The Sonnax instructions, first step read "Install shims provided" This is what caused the 2-3 bang) So I then also replaced the TC. Then the new 629 & 626 transmission problems appeared.

Prior to installing a drain kit I had to loosen all the bolts and let the fluid out slowly into a deep pan. I just left it to drain overnight. While I was at work and the transmission fluid was in the deep pan just what I thought was safely under my truck. My son played with the garden hose spraying water under the high clearance of my truck to get his little brother, on the other side, wet. When I got home, all I saw was a overfilled pan getting fluid on my now dry but tranny fluid covered driveway. I thought I just had too small of a pan. Well, no. The bottom of that nice clean tranny fluid (unbeknownst to me) was some nice clean water. Soon there after I started the tranny work.

I finished tightening up the last flywheel nut and used a clean dixie cup to scoop out the fluid from the full pan. There was no way to lift it with out spilling it. So I got most of it in and started the truck. Ran through the gears and added more fluid. At 11pm I just went to bed. The next morning I went to add the rest of the fluid with the engine running. As I poured another dixie cup of fluid into the realy nice tranny funnel, I could see the nice clean water below the nice clean tranny fluid, flowing down into my tranny. Drove it for a week with water. CEL on all the way. I just didn't have the funds for 6 gallons of Mercon. But then I flushed it by pulling the return line and running the truck while filling it. My now sorry and helpful son watched the clear drain tube for clean red fluid. The watered fluid was just slightly hazy. But after the flush still CEL 629 & 626.

Pulled it again replaced all clutches and steels. Blew out all pistons with compressed air. No visible effect on any parts of the clutch packs, but hell there was water in there. It did however start a rust pattern in all of the fluid passage paths on the steel separator plate. Lots of work and steel wool to clean that up. It is still stained but rust free.

After all of that, the 2-3 bang is gone, there is no longer a delay into reverse, used steels from my dad's '71 T-Bird 429,C6 rebuild, mixed with new steels to get the absolute minimum clearance in each clutch pack. I added my own SS drain (after breaking the cheap drain kit thing). Just a SS bolt with a slot cut in the end, SS nut and the washer from the cheap kit. Doesn't drain fast but I can torque it down so much that there is no way it can leak. But CEL 629 & 626.

It just seams to be dumb luck that I somehow created a wiring problem directly related to TC at the same time I decided to change out the TC. I am so glad I kept my original solenoid pack from the initial rebuild. Easy swap to test. This truck came with the standard cooler in the radiator and also with a second cooler up front. The E4OD Transmission pump was also oversized when I bought the truck. Both were part of the HD package. Temperature is never an issue even if the TC dosen't lock. The CCS issue is just more coincidence?? OMG. http://images.ford-trucks.com/forums...ilies2/mad.gif

So, it is not fixed, but now I have narrowed down where to look. So until Saturday I will just have to use the manual lock up switch....wisely. I don't know under what conditions I would use a Coast Clutch manual lock up.

 

No, that's wrong.
The EPC doesn't control the lockup. It controls overall trans pressure, so there is some indirect link, but you can safely ignore that. It's not the problem. And the E4OD will lock in first gear with the go pedal more than 3/4 down. None of the lockup is EPC or line pressure dependent.

Both of those codes mean there is an electrical fault. The 629 can be caused by the switch you added. There is either an open or short in the coast clutch circuit. It can be the solenoid itself or in the wiring anywhere from the PCM to the solenoid. It's a small probability, but it could also be the PCM. That's very rare.