Flyer

iTrader: (1)

In case ya'll haven't kept up, I had my truck flashed at the dealership a while back to get the so called latest and greatest flash from GM. After everything got straightened out with the tune issue and EDIT not being able to see it. I finally drove it off in a limp mode. It took me forever to get it running decent after that.

Anyways, shortly after I finally droveit out of the service department (that's where it stayed while I got the EDIT stuff figured out with the new segment1 ID), the tranny gave out on me in short order. When it went out it felt like it just missed a shift when it went for 3rd. After it did that once, it never worked after that.

I had that one rebuilt, the builder said in fact the 3/4 clutch set was burnt up pretty bad. Anyways, a rebuild later I put the trans back in ready to go. WIthin 500 miles it does it again. Same exact thing. It just felt like it missed a shift and went into neutral. This is the time it sat up for a couple months 'waiting to gather all the parts' when I decided to go ahead and do the 80e swap.

I had a feeling after the trans did the EXACT same thing the second time that it wasn't the trans, but the tuning or programming in the PCM.

Yesterday I decided to do a little tuning on the truck to try and iron some kinks out and get the idle a little better. I reflashed the PCM with an updated file and go for a test drive. I was easing down the street, still trying to get the laptop up and running. About half way to the end, the trans feels like it went into neutral. I come to the end, and go around the block to verify. Sure enough ... the SAME exact thing that was going on with the 60e's.

I go ahead and get back to the house and put the flash I just overwrote back on and go for another test drive. Everything tested out just fine. I made a couple runs at part throttle-heavy throttle runs to start off. Then I made another couple of runs WOT all the way up to about 110-120 and it held good the whole time.

Moral to the story, I really think the 60e I had would stand up to the power no problem. It had way to clean of a shift to be questionable. I knew this when I was having all the troubles, but I didn't have any proof to back it up until now. So ... if anyone wants a damn good tranny ... PM me.

Mn Avalanche

WOW so let me get this straight it was something to do with the tranny program in pcm. But why would it just go in to neutral.Im a noob when it come's to tranny, or lsi edit..

F8L Z71

Was it going into some weird zero linepressure mode or something? Or was it a upshift to neutral? LOL

Flyer

iTrader: (1)

Apparently it would shift into 3rd, but with somethjing like 0 line pressure. I can only assume that it hitting 3rd gear and 'free wheeling' with the clutches even partially applied, it toasted them in short order.

F8L Z71

That sucks BIG time!

I'm just happy for you that it is now figured out so you can stop spinnin your wheels, or clutch packs anyway, and get to making more power

deezel

Do you know what was different in the flash file that caused the bad 2-3 shift?

ThunderZ28

iTrader: (7)

Flyer I think that may have been part of my problem also with the transmissions I got.
glad you found it