Anybody messing with a 6L80 yet?

[jonrpick]

Just thought I'd ask... I've been waiting on somebody to try it out in a C/K and see how it does. The low first gear (4.027) compared to a 700R4 (3.059 1st gear) would mean great low-speed torque while having an even better OD (double OD's actually).

Anybody know of someone installing one in an older (non-computerized) car or truck?

 

[gmc4cw]

they have only been out for a few months now. most guys wait for a wrecked truck to pilfer so that they can get all the computer controls. I have driven the trucks they come in and that extra low 1st makes a big difference.

 

[uao85]

I was considering getting a 6.2 ltr engine out of an 07 escalade a few weeks ago, and thats what it came with, but other than that, hasnt crossed my mind. From what I have seen, not much of an aftermarket yet since they are so new.

Remington

 

[Babaganoosh]

Is this a 1500 tranny or from a 2500, also what do they come in? Sounds like a pretty interesting deal.

 

[BGKYK5]

As far as I know the 6L80E only comes with the Escalades and Denali's (Denali pickup too?). In a couple years it will probably be optional on almost all full size pickups and SUVs.

 

[Blue85]

It's a 5-speed or a 6-speed?

 

[dyeager535]

Should be 6 if it follows GM naming convention...*4*L60E, *4*L80E, etc., right?

 

[jonrpick]

Should be 6 if it follows GM naming convention...*4*L60E, *4*L80E, etc., right?

Yeah, it's a 6-speed. Interestingly, it doesn't have a true "drive", i.e., a 1:1 gear ratio. The gears are as follows:

1st - 4.027
2nd - 2.364
3rd - 1.532
4th - 1.152
5th - 0.852
6th - 0.667
R - 3.064

So...4 underdrives, and double overdrives. The 1st is much lower than a 700R4 (3.059) and it has a higher OD (.667 vs. .7). What's cool is, at 10mph in 1st gear, a truck with 35" tires and the new 6L80 is turning higher RPMs than the same truck with 31" tires in 1st gear with a 700R4. On the other hand, the 35's/6L80 truck will be turning lower RPMs than the truck with 31's and a 700R4 at highway speeds when in its final gear.

That's pretty darn cool to me.

 

[gmc4cw]

Is this a 1500 tranny or from a 2500, also what do they come in? Sounds like a pretty interesting deal.

all 2500/3500 pickups with gas engines and denali's/escalades.

 

[gmc4cw]

Yeah, it's a 6-speed. Interestingly, it doesn't have a true "drive", i.e., a 1:1 gear ratio. The gears are as follows:

1st - 4.027
2nd - 2.364
3rd - 1.532
4th - 1.152
5th - 0.852
6th - 0.667

should be

1st - 4.03
2nd - 3.06
3rd - 2.1?
4th - 1.??
5th - 0.85
6th - 0.60

or something with less of a jump between first and second and more of a jump between 3rd and 4th. that would be better for towing. if you have driven one of these you realized that it takes off in second. first is only a towing gear.

 

[MaxPF]

My question is how is it contrilled? Individual solenoid hookups like a 4L80E, or does it have an integral controller like the Allison with a CAN bus interface to the PCM?

I don't like the large ratio difference between first and second, nor do I like the lack of a true direct drive. I bet I wouldn't like the price tag of a rebuild either

 

[Babaganoosh]

Thanks guys. Here is some general information allthough its not a whole lot.

http://www.answers.com/topic/gm-6l80-transmission

 

[MaxPF]

The PDF file in that link has more info:

http://www.cadillacfaq.com/stsfaq/tsb/data/tsb/05-07-30-023.pdf

It does have an integrated TCM (Transmission Control Module) similar to the Allison and other newer trannys. It doesn't look like it is based directly off of the 4L80E, but rather is a new design. I bet parts will be pricey and hard to find for some time. I think if I was going to use an expensive electronically controlled 6 speed auto I would go with an Allison.

 

[jonrpick]

should be

1st - 4.03
2nd - 3.06
3rd - 2.1?
4th - 1.??
5th - 0.85
6th - 0.60

or something with less of a jump between first and second and more of a jump between 3rd and 4th. that would be better for towing. if you have driven one of these you realized that it takes off in second. first is only a towing gear.

Hmm... I haven't seen too many late-model Vettes or Caddy XLRs with towing packages It is used in some of the new Escalades and Yukons as well.

Check it:

http://www.gm.com/company/gmability/adv_tech/100_news/transmissions_051806.html

According to GM, 2nd gear is 2.36. And the wide gear spread is for both better launching performance off the starting line *and* better fuel economy when cruising.

 

[jonrpick]

The PDF file in that link has more info:

http://www.cadillacfaq.com/stsfaq/tsb/data/tsb/05-07-30-023.pdf

It does have an integrated TCM (Transmission Control Module) similar to the Allison and other newer trannys. It doesn't look like it is based directly off of the 4L80E, but rather is a new design. I bet parts will be pricey and hard to find for some time. I think if I was going to use an expensive electronically controlled 6 speed auto I would go with an Allison.

I was thinking the same thing at one point... The Allison can certainly handle more torque and has a lower 6th gear, but the 1st gear is 3.10 compared to the super-low 4.03 of the 6L80. Plus, I've heard that the Allison takes a lot of power just to turn the thing...more parasitic drag. It seems I also remembering reading that the Allison is big enough to require reshaping the tranny hump in the floor to make it fit. I can't confirm that, I just read it somewhere...maybe here on CK5.

I didn't figure there were many (if any) folks using a 6L80 just yet. On paper, it seems like it might appeal to some folks and be a good solution when you're trying to decide between gearing for performance or economy.

I personally don't mind the lack of a 1:1 gear...

 

[Greg72]

For what that conversion would cost you'd be better off just building a truck by selecting the axle ratio and tranny (OD or non-OD) for the highway RPMs you want....then buy something like an Atlas or Stak deep-ratio box to get the crawl ratio you need for offroad.

Even with the expense of a custom transfercase, I'll bet you're still thousands of dollars ahead of where you'd be if you chose the 6L80E (aka guinea pig) route...