Is it possible to have an 05 LLY in a 6 sp tranny? I was sure they didnt come out till 06 but when I count the shifts my truck is making, it seems like it is a 6sp. Maybe a dumb quest.

I believe they started making em half through 05. What size tires you have and RPMs @ 75?

i have a 04 lly and i have counted shifts and it sounds like i have a 6 speed

Ive noticed when tc locks up in 5th it feel like a shift.

i have a 04 lly and i have counted shifts and it sounds like i have a 6 speed

what you counted was 5 shifts and a converter locking up, not 6 shifts. ;)

only the 2006+ trucks have the 6-speed

ben

Ya a buddy told me it was prob the TC but it just felt so defined lilke a shift but i guess not. I have 285/75/16. Its a little over 2000rpm at 70mph.

Yeah Im running the same size and running around 1700/1800 @ 70 MPH. But there is a 6 speed conversion that can be done with the tranny in the truck. Not too expensive.

ok well that makes sence

like ben said just converter lock up

hey jtaylor. wondering where i could get a 6 speed conversion and how much?

you can get one from sun coast.

hey jtaylor. wondering where i could get a 6 speed conversion and how much?
Here is the site. http://www.suncoastconverters.com/gmc/gm_products.html

hey jtaylor. wondering where i could get a 6 speed conversion and how much?


www.suncoastconverters.com

I think its around 1600 dollars? Very easy to install, transmission does not have to come out of the truck.

Anybody had the Suncoast conversion done?
Auto transmissions are like mysterious black boxes to me. How do they get another gear ratio out of just changing the valve body and tcm? (TCM=Transmission Control Module?)

Anybody had the Suncoast conversion done?
Auto transmissions are like mysterious black boxes to me. How do they get another gear ratio out of just changing the valve body and tcm? (TCM=Transmission Control Module?)
Here ya a search. (http://www.dieselplace.com/forum/search.php?searchid=6282821)

Thanks! Looks like I was searching on the wrong folder....

Thanks! Looks like I was searching on the wrong folder....
No problem. Dont know if ya know. But you can search multiple folder at one time by holding the "Ctrl" bottom while you click on what you wanna search.

The Allison is already built as a 6 speed. You can have it reprogrammed at an Allison dealer to become a 6 speed.

what you counted was 5 shifts and a converter locking up, not 6 shifts. ;)

only the 2006+ trucks have the 6-speed

ben

LLY's produced mid 05 have the 6-speed Ally.

no they dont and no you cant. the 6 speed did not come out until 06. you can not just take it to an alison dealer and have it reprogrammed. there are actuall mechanical differences. like the valvebody's are different for the 5 speeds and the 6 speeds. as well as a totally different tcm. if you try to make a 5 speed tcm a 6 speed it will freak out

LLY's produced mid 05 have the 6-speed Ally.

um no they dont.

on the suncoast site the conversion cost over $1000. is it worth the price or would it be better to use that money toward a complete new suncoast IV tranny as a six speed and a tcm?

Its worth it to get the sc IV! that tranny is virtually bullet proof! A buddy of mine has one and he tries on a daily basis to break it.