recently as i was driving my truck on ez edge at 3. i went to pass a car and as i was accelerating the tranny suddenly dropped into low gear and the check engine light came on. after removing the tuner, i brought the truck to the dealer who told me that there is a service bulletin out from gm regarding this, the culprit one of seven ( i guess) shifting solenoids is causing the tranny to "fall off". is this what u guys refer to as limping? they gave me a code reader that would read failure at the touch of a button while driving. i ran a week with it and couldn't reproduce the problem, and returned the code reader. the truck ran great for another thousand miles. last night if happened again. any info or suggestions?

When you say dropped into low gear, do you mean that the RPMs jumped 'way up (like a downshift into first)? Or that the RPMs seemed to be limited to 2000 or so?

They are going to move it to "Transmission" where you will get better answers...

But, there is a few things that are not in your post...

What were the stored codes in the truck?
Were you pulling somthing at the time? Empty box? Full load?

Most likely you accelerated with the truck in 5th gear when the problem happened. There is probably a stored TCM code that reads "5th gear incorrect ratrio" when you look it up.
Not 100% sure, but sounds to me like a "limp" caused by a tranny with some miles on it being exposed to to much HP! Pull those codes... if that indeed is the code stored in there, your gonna have to start running your chip lower, if not turn it right off. (Even that is a temporary solution). The Allison is a wonderfull transmission but it does not respond well to increased levels of power unless you beef it up.

i was empty at the time. the truck has only 30k on it. the only code that was read was "5th gear incorrect ratio".

Most definately a limp caused by your too much power... Turn the chip down for the time being. If you wanna prolong the life of the tranny a bit further, I suggest next time you try to pass in 5th gear, lock the truck outa 5th until you are done with the throttle.

This happened with my transmission as well. I kept turning the chip down every time it would happen, eventually my Edge was on "0" and it would still limp during a 5th gear pass. I am addicted to the power of the tuners so I ended up spending the money for a built tranny.

Check out ATS and Suncoast for your transmission upgrading options.
I would say send MikeL (Vendor here) a message but he doesn't seem to respond well to potential customers PM'ing him.

Hope this helped

You limped it.I limped mine on EZ3/bs combo also same way.Looks like you will be saving up for built trans like the rest of us did.No more limps then

this forum is wicked cool. is there something wrong with the tranny. like is it beat? or is a built tranny required for these tuners

a built tranny is not required to run a tuner...but it is piece of mind...most of the tuners with a mild tune will not cause the tranny to limp...the more power you throw at the tranny the greater your chances of limping the tranny are unless you get one built

the average seems to be 80-90 hp. then it is a problem with more than that. if your getting it only on level 3 you need to shut it off and start saving money. do the trans before you do any more damage. the best way to get ahold of mike l is to just call him. he wont bite i promise. look up the number in the vendor section.

i'll give him a call

you've got an LLY motor too which 5th gear won't hold the power the others can.

anyone from ct know where i can find a good allison tranny builder, should i decide to go with a kit?

shoot tony a pm....he did his himself...maybe he would help you do yours.... GMC-2002-Dmax