Has anyone taken a 6 speed allison and installed it behind a 04.5-05 lly? I'm not looking for the upgrade valve body and tcm to convert my transmision. I can buy a 6 speed (used) fairly economically and would like to install it in my truck. What is needed to do this?

Wont read each other. Will still be a 5 speed. Thats all I know

The ECM on a LB7 or LLY non 2006 is the older OBDII interface. The TCM used on the 6 speed uses the CanBus newer OBDII interface. So will not talk to each other. This kit is around $1500.

Only option is the 6 speed upgrade kit that comes with a new valve body plate and locked TCM.

One other option one has said is install 3.42 gears.

Brian

I have a spare 04.5 TCM, isn't there a way to program it to run the 6-speed transmission? Can a person utilize EFILive to do this?

I have a spare 04.5 TCM, isn't there a way to program it to run the 6-speed transmission? Can a person utilize EFILive to do this?

You cannot do it without the convertion.

Other than the canbus/obdII issue, a stock 6 speed can't fit into the 5 speeds spot why? I thought fundamentally these transmissions are the same. Only thing that was different is the valve body and tcm.

Other than the canbus/obdII issue, a stock 6 speed can't fit into the 5 speeds spot why? I thought fundamentally these transmissions are the same. Only thing that was different is the valve body and tcm.

The transmissions will easily interchange ( pure bolt in ). all you need is the 5 speed valve body and NSBU. The 6th gear part of the equation is what won't work without the converted TCM and you can't buy that.

I can't buy the conversion TCM by its self? I guess what is the cost to do the conversion?

Yes you can buy the 6 speed conversion kit. But I do not know whether you can put that in a six speed stock Allison. Only seen 5speed valve body change out. Mike L would know how it all works So I doubt you can just stick in a 6speed stock Allison and use the custom 6speed conversion TCM. I doubt they sell them that way. The valve body may be totally different from both stock 5 and 6 speed Allisons. Goto the Suncoast site for the kit. Its like $1700. But i say all the wiring for the custom 6speed suncoast TCM is designed to connect to the 5 speed setup. The NBSU is external on 5 speed verses the 6 speed which is internal.

Brian

I had an option of a 6 speed transmission for around $1500. I thought I could make it work. Called the guy that had it for sale and told him I wasn't interested, because I needed to many upgrades to do it. Thanks, for all your help:)

Has anyone taken a 6 speed allison and installed it behind a 04.5-05 lly?

has anyone ever used the search feature????????

has anyone ever used the search feature????????

So it can be done?

So it can be done?

As a 5 speed only.

has anyone ever used the search feature????????

Am I missing something, if I did a search (1/2 Hour and no right answers) and couldn't find my answer, aren't we allowed to post a question to answer my question? If you knew the answer earlier why not direct me in the right place instead of giving attitude and posting this response. I'm trying to learn and your reponse is dis-respectful when you could have been helpful rather than critical.

I don't have 16,000 posts, I'm at less than 600 and I'm still learning, I spend a lot of money on suppliers to this site which should allow me to ask questions when I can't find the answer I was looking for.

Now I'm off my soap box, thanks Mike and Tanc for your responses, you help'd me alot in my decision.

As a 5 speed only.

Thanks Mike I thought that was the answer but was unsure what DURAtotheMAX was getting at. I was thinking maybe he meant it was possible to use a 6 speed allison and the suncoast TCM. So no matter what one has they have to USE the 6 speed valve body and suncoast TCM even in an Allison 6 speed to get it to work. Again no idea about the wiring between the two.

Thanks again Mike.
Brian

http://www.dieselplace.com/forum/showthread.php?t=338391

that was the most recent one (out of about 30), it was on the second page of the same section you posted this thread in. ;)

Im still learning too; everyone is. If the regular search doesnt turn up anything in the future, try the google search feature too.

ben

http://www.dieselplace.com/forum/showthread.php?t=338391

that was the most recent one (out of about 30), it was on the second page of the same section you posted this thread in. ;)

Im still learning too; everyone is. If the regular search doesnt turn up anything in the future, try the google search feature too.

ben

Thanks, that would have saved me a whole lot of questions and time.

http://www.dieselplace.com/forum/showthread.php?t=338391

that was the most recent one (out of about 30), it was on the second page of the same section you posted this thread in. ;)

Im still learning too; everyone is. If the regular search doesnt turn up anything in the future, try the google search feature too.

ben
Figured you might mean that that not possible but was not sure. thanks for the link too.

Brian

Not trying to hijack this thread...
What about the suncoast six speed conversion? How well do they work with a built SCIV?
Thanks,

Not trying to hijack this thread...
What about the suncoast six speed conversion? How well do they work with a built SCIV?
Thanks,

They work, the things I don't like are 1.) the price would take years to recoup in fuel savings 2.) the TCM is locked and cannot be adjusted for shift points, tire sizes, ect. But yes they do give you 6th gear.

One other option one has said is install 3.42 gears.

Brian
Better option is to lift the truck and put on bigger tires....
It's what every red-blodded American male does..
http://www.youtube.com/watch?v=C2bGUeDnqPY
:D

Better option is to lift the truck and put on bigger tires....
It's what every red-blodded American male does..

Some of us like to go fast, have a truck that's easy to get in and out of, and just don't want to have a truck sitting so high for show - 80% of the lifted Duramax's I've seen never go offroad.