Allison Fast Learn - Does it work?

[Billy14]

Haven't noticed anything for quite some time regarding the Allison Fast Learn technique > dropping the shift lever to 1 three times in a row from 55 mph & coasting down to a stop. :eek:

Has anyone proved this without a doubt to be fact or fiction?

Billy

[MadDuraMax]

Probably because it does not exist, an urban ledgend no doubt from our friends at F*rd. The ONLY way to get our Allisons into fast adpative learn mode is with a Tech 2.

Mark

[Billy14]

Thanks Mark, kinda figured that.

Billy

[Gbenzx01]

Billy,

I do remember something on DP abt this scheme, may try search using, fast learn or relearn just to see.
I believe one or more claimed it worked for them & of course not seeing this I wouldn't say but can say, Not Me Boss. :(
The last I read of it I think the guy almost left his teeth on top of the steering wheel!
And the report back guy never returned to tell us how he came out, if of course he came out.
If I needed this I would drop by the nearest Allison shop & discuss with them, since most of these people we've dealt with over the years are pretty sharp abt these transmissions.

Thnx, Gben

[SoCalDMAX]

This is a pretty good one!

At one time, several of our members had a problem with their trannys not shifting into 1st when coming to a stop. So one of the Allison experts had mentioned to try dropping it into 1st at 50 or 60 mph to teach it to downshift properly. IIRC, this technique worked for the members, but some of us misunderstood and thought this was a way to go into fast learn mode. I was one of the members who misunderstood and spread it around.

If one drops the shifter into 1st at 60mph, the tranny will merely downshift through the gears and slow the truck down to 1st gear. It's not violent, nor dangerous for the tranny, but it shouldn't be done anywhere near traffic. ;)

I'm not telling anyone to do it anymore, it really serves no purpose.

There are 2 different ways to reset the Tap cells and make the transmission go into fast learn. The best way is with the Tech II. I've been told that the other way is if power is completely removed from the truck (both batteries disconnected) then the cables are shorted together to remove any residual voltage that is storing info in the Tap cells. I have not tried this, and am not endorsing it.

If you just drive it the way you want it to shift, it will learn normally, and it doesn't take all that long.

Regards, Steve

[Billy14]

Steve,

I think I was probably the one that started the won't downshift into 1st holding throttle deal. I noticed it on a grade, holding throttle only with no brake coming to a complete stop. Starting off again into traffic took around 1800 rpm to get the truck to move & when it did..........BANG! The tranny finally dropped from 2nd to 1st with a jolt that would jar your teeth out. They blamed it on the 295 BFG's. I said BS. I went back to the dealer & they pulled 2 new totally stock Dmaxes off the line & I was able to get both to do the same. They got with GM engineering & came up with a TCM reflash in a week. Mine has worked beautiful ever since. :D

Thanks,

Billy

[MadDuraMax]

Ok,

Here's a portion of the email I got from GM awhile ago...

"The LCT1000 as set up in the GMC product will not enter the fast adapt mode through a gear selector routine. In order to enter fast adapt learn mode the tcm must be cleared and the process started using a Tech 2. There is a series of service bay shifts to be performed and then aprox. 12-14 additional shifts while driving to complete the "fast" stage of the relearn process.

I hope this answers your question regarding the Allison LCT 1000 fast adapt mode."

I hope you guys are right about starting this, I can just see those PSD guys busting a gut over Dmaxs downshifting on the back roads. I think the only "Fast learn" thing you'll get from this is not to do it again! :D

Mark