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DURAtotheMAX
September 21st, 2009, 05:35 AM
On the early 5-speed TCM OS', if you are cruising along on the highway at say 65mph and you go to pass someone, the TCM unlocks the converter, downshifts from 5-4, then relocks the converter, then upshifts back to 5 when you get to the appropriate 4-5 WOT upshift point (say 80mph or so).

This is really annoying because for those of us who run looser converters, we run into (once again) probably THE most annoying programming thing about the whole allison TCM......it doesnt lock the converter when tcc slip is above X rpm!!!

So what happens with bigger power and a looser converter, you go WOT, it unlocks and goes from 5-4, unlocks and whoo hoo you're sitting there in the passing lane screaming at 3200rpm WOT in 4th gear NOT accellerating at all because you just blew through that tcc relock X-rpm slip limit table. 5 seconds passes...rpms still screaming unable to pass the car because you're blowing through the converter...oh ok here we go, NOW the TCM decides to relock the converter in 4th gear. BOOM, truck rockets past the car, shifts back into 5th and you're on your way.

BUT, the later TCM OS's keep the TCC locked during this scenario. I love the 01 TCM because it shifts nicely, but forget passing anyone on the highway at a rate faster than a geo metro with a big tune in, unless you manually shift to 4th at less than full throttle (so the TC stays locked), then go WOT and manually shift back into 5th.

During the winter I run my stock 05 TCM because the LLY auto high idle works on it. WOW what a difference when I go WOT to pass someone!

Is there any possibility that at some point Ross and Paul could take a look at that? The fact that 01 TCM's unlock the TC at WOT kickdown and the 05 TCM's dont might make it easier to track down in the code?

thanks
Ben

camcojb
September 21st, 2009, 12:09 PM
On the early 5-speed TCM OS', if you are cruising along on the highway at say 65mph and you go to pass someone, the TCM unlocks the converter, downshifts from 5-4, then relocks the converter, then upshifts back to 5 when you get to the appropriate 4-5 WOT upshift point (say 80mph or so).

This is really annoying because for those of us who run looser converters, we run into (once again) probably THE most annoying programming thing about the whole allison TCM......it doesnt lock the converter when tcc slip is above X rpm!!!

So what happens with bigger power and a looser converter, you go WOT, it unlocks and goes from 5-4, unlocks and whoo hoo you're sitting there in the passing lane screaming at 3200rpm WOT in 4th gear NOT accellerating at all because you just blew through that tcc relock X-rpm slip limit table. 5 seconds passes...rpms still screaming unable to pass the car because you're blowing through the converter...oh ok here we go, NOW the TCM decides to relock the converter in 4th gear. BOOM, truck rockets past the car, shifts back into 5th and you're on your way.

BUT, the later TCM OS's keep the TCC locked during this scenario. I love the 01 TCM because it shifts nicely, but forget passing anyone on the highway at a rate faster than a geo metro with a big tune in, unless you manually shift to 4th at less than full throttle (so the TC stays locked), then go WOT and manually shift back into 5th.

During the winter I run my stock 05 TCM because the LLY auto high idle works on it. WOW what a difference when I go WOT to pass someone!

Is there any possibility that at some point Ross and Paul could take a look at that? The fact that 01 TCM's unlock the TC at WOT kickdown and the 05 TCM's dont might make it easier to track down in the code?

thanks
Ben

the later six speeds have the same problem.

Jody

cmitchell17
September 29th, 2009, 03:24 PM
I think I noticed that tonight on my LLY, but it locked fast. It was manily unlocked before the turbo had fully spooled though, plus I have a 1056 so it dosent seem like its blowing through the converter.

DURAtotheMAX
May 21st, 2014, 05:39 AM
Ive been beating this dead horse for almost 8 years now...finally see the light at the end of the tunnel with this upcoming update to the cal files...

But wondering if this table is included in that update??? (keep the TCC locked on WOT downshift)

Its one of the things I love about the 04-05 LLY TCM OS...but hate the way the 04-05 LLY TCM OS shifts otherwise.

cindy@efilive
May 21st, 2014, 08:40 AM
Talk about bringing a thread back from the dead Ben....I've PMed you.

Cheers
Cindy