Help! Replaced transmission, problems (5r55W, 2002 Explorer). | Ford Explorer Forums - Serious Explorations

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Help! Replaced transmission, problems (5r55W, 2002 Explorer).


Active Member
September 5, 2006
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City, State
Year, Model & Trim Level
2022 Explorer ST
I just swapped out my 5r55w with a low miles used one. I put a quart of mercon V in the converter, a new filter, and 4 quarts of fluid in the pan before starting it up. I started it up and clicked it through the gears while up on jackstands. I went to check the fluid level to add more (by removing the inner plug) and the fluid that I put in the pan started running out. I clicked through the gears a couple more times and tried checking it again-a steady stream of fluid ran out again. After running the engine for a few minutes, the bottom of the pan was still cold and I could not feel any warmth on the cooler lines as well.
What have I done wrong? I seem to think that the pump isn't priming-how can I get it to prime?

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Fluid is running through the cooler lines and the level drops when the vehicle is running. Car will not move at all.

I do remember something odd, when I removed the old transmission, I was able to turn the motor with a socket on the crankshaft quite easily to get at the converter nuts. When I installed the new transmission, the motor turned okay with the socket to get the converter nuts started but when I went to tighten them up, I could no longer turn the motor with the socket and had to use the starter to bump the flexplate around. It also put up a fight the first time I tried to start it. Did I maybe do something to the torque converter?
Anyways, I'm going away for 2 weeks tomorrow night so it looks like we'll have to fit us and the dogs into the wife's SVT focus to get us to the airport tomorrow night (2h drive).

Maybe the torque converter wasn't properly seated? I hope that the converter, and pump weren't damaged. As a general rule, always flush the front cooler, and internal cooler in the radiator before you install a new transmission. Junk from the previous transmission could get pushed into the new transmission, and clog things up.

I flushed the cooling lines out with compressed air, blew air through the radiator connections, and then pumped Mercon V through them until it ran nice red fluid. I got the converter with the new transmission but only drained it by pouring fluid out of the snout (I didn't realize it had a drain plug until the post-mortem on the old unit). I added a full quart of fluid sothere was likely some of the remaining fluid in it. Is it possible to over-fill the converter? Will it cause problems? FWIW, the fluid that I got out of the new gearbox was in excellent shape.
I will drop the pan when I get back but I just don't have the time to do it right now.
Thanks for the help.

If you could turn the motor before and then you do not have the tc in all the way its binding it up. I had the same problem with a galant had to take the tranny back out and check the seal and put converter back in. So Brooklyn was right on with that.