After driving about 100 miles of interstate at 75mph i pulled off to get some fuel, about half way down the off ramp my service engine soon light came on. I got fuel and went to pull back out on the interstate and tranny wouldnt shift out of 3rd gear. I pulled over and shut the truck down, restarted and it did it again. So i pulled over and shut the truck down again, sat there for a couple minutes trying to figure out what i was going to do. I decided to take it easy up to the next exit, so i started the truck and took off and then it shifted just fine. I drove it another 50 miles on home with no problems. I ran a few errands around town after i got home and had no problems at all. Also, i had my efi turned down on the 50ish horse economy tune when this all happened. Any ideas?

Have you ever had this happen before? Doesn't sound like you are running too much power. I had this happen to me before and I thought it was my tranny but it was my fuel filter. The fuel had gelled in the filter. I changed the filter and it fixed the problem.

No this has never happened before. My EFI is set at about 275ish above stock on the highest setting so its puttin out a little power. Ive never had any problems with gelling up before but thats not to say that isnt the problem. I think tomorrow im going to change the fuel filter and the spin on tranny filter and see if that changes anything. I drove it 50 miles or so today, some in town and some highway and havent had any problems. My service engine soon light is still on but everything is still shifting and running just fine

Hopefully it is just a filter. 275 above stock will eventually kill a stock tranny. I recently rebuilt mine because it would go into limp mode with any tune above stock. When I got it apart all the clutch packs except the C5 were showing signs of slipping.

After driving about 100 miles of interstate at 75mph i pulled off to get some fuel, about half way down the off ramp my service engine soon light came on. I got fuel and went to pull back out on the interstate and tranny wouldnt shift out of 3rd gear. I pulled over and shut the truck down, restarted and it did it again. So i pulled over and shut the truck down again, sat there for a couple minutes trying to figure out what i was going to do. I decided to take it easy up to the next exit, so i started the truck and took off and then it shifted just fine. I drove it another 50 miles on home with no problems. I ran a few errands around town after i got home and had no problems at all. Also, i had my efi turned down on the 50ish horse economy tune when this all happened. Any ideas?

Maybe its nothing related, but mine acted like that when the adapter housing cracked. Did you check your fluid level?

-Wardster

did you read the codes? If you have EFILive you can check what codes came up

I changed the fuel filter and the spin on tranny filter, everyting is still good. Ive driven it the last 3 days and have had no problems again, yet. The fluid level is fine and i havent had time to check the codes but the light went off monday after i had driven it about 10 or 15 miles.

I changed the fuel filter and the spin on tranny filter, everyting is still good. Ive driven it the last 3 days and have had no problems again, yet. The fluid level is fine and i havent had time to check the codes but the light went off monday after i had driven it about 10 or 15 miles.
I think you need to start looking into a tranny kit that can hold that kind of power. even tho you had your tune turned down to 50 ish hp. you say that you have run 275 hp over stock on a stock tranny, I think you over powered the tranny. you will prob have this happen more frequently in whatever power level you run.

Hopefully it is just a filter. 275 above stock will eventually kill a stock tranny. I recently rebuilt mine because it would go into limp mode with any tune above stock. When I got it apart all the clutch packs except the C5 were showing signs of slipping.

275 at the wheels will do more thna kill it.. :lol:
as you said, my c'3 were welded to the frictions

Yeah i knew it was going to happen sooner than later, i guess i was just hoping for later. Im just gunna take it easy and limp it through for a month or two till i have a little more cash and then build it to hold whatever i can throw at it

Check for codes