Hey all,

I just finished re-installing my E4od after a full rebuild with new gaskets, seals, frictions, steels, billet TC, Transgo Tugger kit, knurled pump bushing, and everything else in the PA cargo K36900E rebuild kit. I also upgraded planetaries, sprag, and machined center support per the update handbook. I cleaned and re-used the solenoid pack. The pump+gears looked fine, so it just got the transgo tugger upgrades, bushing, viton seal, and a good cleaning. I was expecting to have a nice running transmission after all that, but unfortunately I'm still having some issues that I hope you can help me diagnose.

Reason for rebuild: The front seal was the old rubber seal and cracked, leaking out the trans fluid. By the time it was bad enough for me to notice, I was on the highway and had to limp it off with very low fluid. This burned up the direct frictions. Judging by the tag (I can post this if you have a better decoder) this was a ~2004 ford reman. The truck has ~170k miles and the other frictions looked pretty good, so I doubt this transmission had a ton of use.

The good: Driving in D feels okay. Shifts are a little lazy which is surprising with the tugger installed, but it does shift and the TC does lock enough to feel in all gears.

The bad: Reverse engagement is slooooow and sometimes requires revving to ~1800. This was also true before the rebuild. Driving the truck normally will always eventually throw a code 62. I don't want to drive it too much until I resolve this slip to avoid burning up my new torque converter.

Diagnostics so far:
Pressure test shows normal pressure ~66psi in PND and 2. Manual 1 is low at 60psi. Reverse is very low, dropping to 40 at the time of shift and settling around 50-55psi. Pressure rise is also very low when compared to the ATSG numbers. Stall line pressure doesn't really get above ~100 PSI in any gear when revving.
Temperatures are normal.
KOEO test shows all good except for code 62.

Next steps:
I'm going to check the EPC solenoid resistance and wiring since pressures are poor.
If the EPC is okay, I could try removing the pan and trying pressure tests at all of the test points.
I'd like to test the FIPL just in case it is not detecting pedal travel and ramping pressure appropriately. That wouldn't explain the low reverse pressure, though.

Any tips or suggestions would be greatly appreciated!

 

You won't hurt the torque converter doing this. You most likely have already damaged the reverse clutch, and possible the direct clutch, too.

You have a leak in the reverse circuits. That is what you need to find. Did you air test reverse (and the others) while assembling it?

I think you need to rebuild it again. Revving to ~1800 RPM to get a clutch to engage usually wipes that clutch out in 2-3 seconds. Sorry to have to deliver the bad news.

 

Thanks Mark. I did pressure test on the bench and it was fine. This was also happening (but a little worse) pre-rebuild and I thought it must be a piston seal or something in the reverse circuit. New seals and frictions throughout, same problem.

I still don't get the low pressure in manual 1 or low pressure rise.

 

The coast clutch is on in reverse and manual 1. That could be a leak point.

 

I finally had time to clear space in the garage and take out the transmission again. At least it goes a lot quicker with practice

I took out all the valve bodies and did an air pressure test. Here is a recording of the air check on each of the ports (except Coast- I didn't have anything to adapt the square hole on hand) Reverse is great. Nice thunk and no air noise at all. Same with Intermediate and Overdrive. The Direct and Forward both have kind of a whooshing. It's captured pretty well in the video. I'm not sure if that's just normal for air and the metal seals there.

I'll try and get something set up for the coast and check that.

 

And here is the coast clutch test. Normal hiss I think?

Before I performed this test, I removed out the pump and coast clutch to take a look at the seal. However, when I pulled the pump, the boost valve was completely popped out of the bore! The snap ring must not have seated. Yeesh. I'm guessing that was the issue.

Now to take apart the other clutch packs to see what they look like.

 

All the clutch packs still look great along with the frictions. I think the loose boost valve explains the slow/no reverse engagement, low pressure rise, and code 62. Is there anything else I should check before re-assembly?