So, as many of you here know I recently swapped a reman'd 5.4L 3V motor into my '04 XLT Screw 4x4. It's been running flawlessly, without a single hiccup. Until today. As I'm making a Costco run, i pull up to a red light and apply the brake. As I come to a stop the motor just dies, like it was a manual and I didn't release the clutch. I turn the key, it fires right back up and I drive on to Costco. While in the parking lot I try to get it to do it again, but to no avail. It's running like a Swiss watch.

The CEL isn't lit, but I immediately pull up Torque pro and connect to my OBD2 reader. Nothing. No codes thrown, no codes pending. Passed every test. The only thing that I can think of is that I have been experiencing very mild transmission slippage lately. Reverse is slipping for sure, so much so that it has thrown the P0722 code (no signal form output shaft speed sensor). I have felt a slightly more pronounced slip in 3 and 4th gear the past few days, but nothing major. I do plan on replacing the transmission with a reman'd unit as well.

My "seat of the pants" diagnosis is that it stalled at the light due to a clutch pak or band sticking. What do you guys think?


Oh, BTW the 4R75E transmission has about 140K original miles on it.

 

When I'm in a bind like this where I can't figure out the answer to a very intermittent problem, and I also know of something that needs to get fixed that might be related, I move forward with the need and see if it fixes the other symptom. My $0.02 .

 

And . . . if it is anything sticking in the transmission that would cause the engine to stall when coming to a stop, it would be the torque converter clutch.

 

I'm of the same opinion. Always fix what's obvious first. There are often relationships between systems that may not, at first glance, be plain.

It would have to be a stuck-on torque converter clutch, if anything, as CC noted.

 

Thanks for the replies fellas. It was just so odd that it died just out of the blue . Comes to a stop and the RPM's just dropped to zero. Then it started right up without any issues. I do feel a bit more slippage in 3rs and OD though.

I'll be ordering a rebuilt transmission from Fraser engines on Monday. Looking at putting a Detroit TruTrac in the rear as well, as long as I'm going to have it apart. Maybe go through the front hubs to make sure everything is working properly as well.

 

Transmission failure is my worry now at 200k . I just can't decide who I'm going to use when it does . Let us know how it goes . I think you have your answer in the symptoms of a failing trans .Regardless you have to do the tranny . So after that you will know . I hope you have a cooler on it and maybe a good drain pan for later fluid changes . I think changing fluid every 50k or so is a good thing and doing it slowly over a week or so .
I did think about using a local rebuild but everyone I talked to says their experience was the warranty was useless . I have your same trans.

 

Now, my example is a motorcycle, but it could apply. How about a vacuum hose somewhere?

I had a bike that began stalling out...intermittently. Then, it became worse over the course of a week or two. Turned out one of the vacuum hoses from the airbox to the throttle body was cracked/dried out. It was intermittent at first because the hose was only partially losing vacuum. As the hose dried, cracked and vibrated around, the stalling started to happen more frequently.

Since you did an engine swap, maybe its something simple like this...of course, finding all the vacuum lines and hoses isn't exactly simple on a modern engine!

 

While this isn't the case, it is a very good post/point.