Firm Shift tune plus Vette Servo w/ 4L60E

[Mossyoakglock]

I have a 4l60E with about 113K on it and currently have only a Vette Servo on the transmission. I want to tune some TM out of the tranny and considered also installing the firm shift TCM tune.

 

Will that shift too hard and possibly damage the transmission? Do you think it would also be too hard from a perception/feeling standpoint?

[sefiroxx]

I've installed one - without a tune adjustment. Only problem I have is the 1-2 shift under med acceleration. It pops in with concern. No issue under high acceleration so I've taught myself to be easy through 1-2 under a normal stop resume

 

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[arcasey]

It shouldn't be too firm, unless it slams into gear. It is better for a transmission to shift a little harder than what most people are used to in a stock vehicle. All the transmission shops around here increase the shift firmness (i.e. turn up the shift pressure) on all the rebuilds that they do. What kind of tuner are you going to use? I used a diablo trinity on my 2011 6L80 and even on the lowest pressure setting in the firm shift tune mine would slam under WOT from 1-2. Everything else was fine. I ended up lowering the shift point down to around 5,000 RPM, if I remember correctly, and that seemed to soften the 1-2 shift up enough that I stopped looking backwards to see what fell out.

 

Used the same tuner on my 2015 Denali with the 6-speed transmission and didn't have those overly hard 1-2 shifts under WOT so I'm guessing either there was something wrong with my other one or each one just reacts differently. Or, and probably the more logical answer, the updating of the software when I installed it on my 2015 fixed some of the issues with the GM 6-speed tunes. Either way good luck and let us know how it goes.

[intheburbs]

Torque management is there to reduce wear and improve durability of powertrain components. Remove at your own risk.

 

That being said, I removed about 50% TM with my Blackbear tune in my Suburban, but it's the heavier duty 6L90, so I figured it'd be a little more tolerant of the added stresses. 160K miles and it still shifts perfectly.

 

BTW, a close friend of mine is a transmission validation engineer at GM, who worked on the 6L80/6L90 transmissions during development. Those first two sentences are his exact words.

[arcasey]

Torque management is there to reduce wear and improve durability of powertrain components. Remove at your own risk.

 

That being said, I removed about 50% TM with my Blackbear tune in my Suburban, but it's the heavier duty 6L90, so I figured it'd be a little more tolerant of the added stresses. 160K miles and it still shifts perfectly.

 

BTW, a close friend of mine is a transmission validation engineer at GM, who worked on the 6L80/6L90 transmissions during development. Those first two sentences are his exact words.

 

Just to clarify, he has a 4L60. I was using my experience with a tuner and 6L80 as an example. Unfortunately my 4L60 (96 K1500) is just a bit too old to program with "good" boxed tuners lol.

 

What intheburbs says is correct, the torque management is there to help reduce wear and tear. However, the 6L80/6L90 transmissions are much more robust than the 4L60s. I would not advise removing torque management from the 4L60.

[Mossyoakglock]

Correct. I'm running the 4L60E. If I remove some TM I'm only going to remove about 20% and see what happens.

 

Also, I don't drive my truck hard or do anyWOT runs and drive fairly conservatively. I just want to reduce a little of the sluggishness.

[SILVER SLED]

The 6L trannies and the 4L trannies are very diff animals when it comes to torque management. And torque management has nothing to do with how the trans actually shifts on a 4L. A 4L trans with no torque management will bang gears very hard when driving. With stock torque management in place it still bangs gears very hard but you don't feel it,because torque management basically reduces engine power during the shifts, which is easier on the drivetrain. You should be fine taking some torque management out. In my trailblazer ss I had a separate tcm with no torque management for track events and some Friday and Saturday nights. It takes about 30 seconds to swap the tcm's.