5 Speed To 6 Speed Allison Conversion

Hulk1999 · November 5, 2008

Has anyone ever added the 5 speed to 6 speed conversion kit from SunCoastConverters to their Allison or know someone who has? I wonder if it's worth adding to my truck. Having a double overdrive sounds good to me. I wonder how the big block would react to it.

Hulk

merlin5577 · November 5, 2008

Has anyone ever added the 5 speed to 6 speed conversion kit from SunCoastConverters to their Allison or know someone who has? I wonder if it's worth adding to my truck. Having a double overdrive sounds good to me. I wonder how the big block would react to it.

Hulk

Out of curiousity, how much does that kit go for?

Hulk1999 · November 6, 2008

ALLISON 5 SPEED TO 6 SPEED

2001-05

Part No. A1-6VB-TCM

Price: $1648.00*

CONVERT YOUR 2001-2005

ALLISON 5 SPEED TO 6 SPEEDS

Drops 325 engine rpm @ 75 mph with 3.73 gears. Increases fuel economy 1 - 1.5 MPG, reduces engine noise while cruising, a truck with 3.73 gears that normally likes cruising at 62 MPH will now cruise nice at 72 MPH. The gear ratio in your 5 speed is .71 and our 6th gear will be .61. 6th gear can be disabled with your two haul button and 5th canceled with OD off. Requires valve body and tcm change (1 hour). No wiring, no modifications required. Indicate LB7 or LLY & year.

BlackSilver · November 6, 2008

My last truck had the Allison 5 speed.

My current truck has the Allison 6 speed.

I wouldn't have paid $1650 for the extra gear!

The difference is modest.

Hulk1999 · November 6, 2008

was the big block ever paired with a 6 speed?

Hulk

98silvz71 · November 6, 2008

Essentially you have a 6-speed. When the torque converter locks up while in 5th gear thats what makes the engine speed drop down. The Edge system has the current gear and my Dmax goes into gear 5 about 45ish mph. Above that is when the torque converter locks and the rpms drop.

Don't get me wrong though. I kinda want to do it too, but get a built Allison at the same time.

merlin5577 · November 6, 2008

ALLISON 5 SPEED TO 6 SPEED
2001-05

Part No. A1-6VB-TCM

Price: $1648.00*

CONVERT YOUR 2001-2005

ALLISON 5 SPEED TO 6 SPEEDS

Drops 325 engine rpm @ 75 mph with 3.73 gears. Increases fuel economy 1 - 1.5 MPG, reduces engine noise while cruising, a truck with 3.73 gears that normally likes cruising at 62 MPH will now cruise nice at 72 MPH. The gear ratio in your 5 speed is .71 and our 6th gear will be .61. 6th gear can be disabled with your two haul button and 5th canceled with OD off. Requires valve body and tcm change (1 hour). No wiring, no modifications required. Indicate LB7 or LLY & year.

WoW! Thats a lot of coin for 1 extra gear!. It would be far cheaper to change out your rear gear to a lower ratio.

was the big block ever paired with a 6 speed?

Hulk

I dont believe so.

svensk · November 6, 2008

ALLISON 5 SPEED TO 6 SPEED
2001-05

Part No. A1-6VB-TCM

Price: $1648.00*

CONVERT YOUR 2001-2005

ALLISON 5 SPEED TO 6 SPEEDS

Drops 325 engine rpm @ 75 mph with 3.73 gears. Increases fuel economy 1 - 1.5 MPG, reduces engine noise while cruising, a truck with 3.73 gears that normally likes cruising at 62 MPH will now cruise nice at 72 MPH. The gear ratio in your 5 speed is .71 and our 6th gear will be .61. 6th gear can be disabled with your two haul button and 5th canceled with OD off. Requires valve body and tcm change (1 hour). No wiring, no modifications required. Indicate LB7 or LLY & year.

WoW! Thats a lot of coin for 1 extra gear!. It would be far cheaper to change out your rear gear to a lower ratio.

was the big block ever paired with a 6 speed?

Hulk

I dont believe so.

I use to drive a topkick 8.1L with the 5spd. Far as I know they all came with 5's

hotbread597 · November 9, 2008

I have a buddy in town with a 2006 GMC Sierra CC SB 4x4 with a 8.1 and a 6 speed allison and 4.10s. He loves it, says it will pass everything but the next gas station! lol

Burbman · November 10, 2008

ALLISON 5 SPEED TO 6 SPEED
2001-05

Part No. A1-6VB-TCM

Price: $1648.00*

CONVERT YOUR 2001-2005

ALLISON 5 SPEED TO 6 SPEEDS

Drops 325 engine rpm @ 75 mph with 3.73 gears. Increases fuel economy 1 - 1.5 MPG, reduces engine noise while cruising, a truck with 3.73 gears that normally likes cruising at 62 MPH will now cruise nice at 72 MPH. The gear ratio in your 5 speed is .71 and our 6th gear will be .61. 6th gear can be disabled with your two haul button and 5th canceled with OD off. Requires valve body and tcm change (1 hour). No wiring, no modifications required.

Indicate LB7 or LLY & year.

That last line sounds like it's only available if you have the Dmax diesel either LB7 or LLY. I would sure it even wowks with the 8.1 PCM.

Hulk1999 · November 11, 2008

Allison has it's own PCM called, get this, a TCM. I don't think it matters what engine you have provided the TCM is programmed to shift at a certain point.

HULK SMASHED!!!

Stewmeistr · November 17, 2008

I have already emailed them and talked to a guy there at SUNCOAST.. he said, sorry its diesel specific...

I said, but I have an Allison too, he said that its not made for the big block. I know, I know, it didn't make sense to me either, but thats what he said. I'm sure that if he thought he could sell 1200.00 worth of parts he would have... he just said sorry. Its for diesels only.

Now, from what I understand, the 2006 and up 8.1's all have the 6 spd? That'd be the ticket. Should be able to get it from GM then wouldn't you think?

Rob