More transmission problems with the 2500

[Easemaster3000 [Veteran Member]]

Seems my sprag has broken again in my 4l80e. 44 miles since rebuild and have not been ruff on it. Climbed a few hills but nothing crazy. Hasn’t been running 100% right thought is was fuel pressure. That’s what I was testing when trans went. Between that and getting trans cooler on I haven’t had much time to drive it. Im thinking somthing is causing it to fail, doesn’t seem right to go after so few miles. Maybe in tune or somthing I’ve done? Any ideas?

[Reserector [Veteran Member]]

That's not good. You should get at least 100 miles on a rebuild.
What are the symptoms?

[Easemaster3000 [Veteran Member]]

Same as first time takes 1,2 and 3. Won’t take D or R. Got hold of my transmission rebuilder this morning he said defiantly sprag. Nothing I did. More than likely it was in over drive at a low speed and when it shifted down it broke, from what I understand. He’s gonna get with my tuner to see the specs of my tune and see if we can keep it from shifting into overdrive unless I’m on the highway at high speeds. I guess tow haul will solve this. When the key is cut off the tow haul will recycle and id like it to stay off with a switch all the time. On the bright side it’s not gonna cost me much but I am gonna have to take it back down there.

[Reserector [Veteran Member]]

I was wondering if there was something wrong when you felt the need to install that huge cooler. I suspect it is trying to do two things at once, and fighting itself. I don't know but like a stuck valve, or fluid bypassing a seal or something. Maybe programming, but I have a hunch it is mechanical.

I've used tow/haul to experiment with programs while leaving my normal shift tables alone. Then I reset it. Definitely not something you want to have to remember to turn on every time you drive.

I'm no expert. My only experience is going through my 4L60E myself a bunch of times. It's awesome now, but I paid dearly for that experience with time and money. I hope you get yours sorted this time. They get easier to remove each time, but it's still a drag. Last time I dropped mine it took me just under 30 minutes by myself.

[Easemaster3000 [Veteran Member]]

I was wondering if there was something wrong when you felt the need to install that huge cooler. I suspect it is trying to do two things at once, and fighting itself. I don't know but like a stuck valve, or fluid bypassing a seal or something. Maybe programming, but I have a hunch it is mechanical.

I've used tow/haul to experiment with programs while leaving my normal shift tables alone. Then I reset it. Definitely not something you want to have to remember to turn on every time you drive.

I'm no expert. My only experience is going through my 4L60E myself a bunch of times. It's awesome now, but I paid dearly for that experience with time and money. I hope you get yours sorted this time. They get easier to remove each time, but it's still a drag. Last time I dropped mine it took me just under 30 minutes by myself.

My transmission guy and tuner guy know each other. Hopefully they can get it figured out. I’m afraid it’s above my head. As long as I was on the road the temp would stay down but when I’m in the woods with no air moving at crawling speeds the temp would start rising. When I swapped a 6.0 and 4l80e into my single cab several years ago I got pretty good myself pulling the transmission. Did you pull the tcase every time or pull together?

[Reserector [Veteran Member]]

I pulled the t-case separately.

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