Allison 5 Speed To 6 Speed Conversion

greenhog · November 13, 2007

I have an 01 2500 HD LB7 with a 5 speed allison trans. Internally this trans seems to be the same as the 6 speed except for the clutch combinations it uses to get the 6th gear. Is it possible to convert the 5 speed to a 6 by changing the electronics?

Flash2004 · November 13, 2007

I have an 01 2500 HD LB7 with a 5 speed allison trans. Internally this trans seems to be the same as the 6 speed except for the clutch combinations it uses to get the 6th gear. Is it possible to convert the 5 speed to a 6 by changing the electronics?

I'd sure be keen to know the answer to that one too. Especially if its not just another gear on top but gives a wider spread of ratios. cheers

greenhog · November 15, 2007

Any Allison techs out there?

RCH · November 15, 2007

I have an 01 2500 HD LB7 with a 5 speed allison trans. Internally this trans seems to be the same as the 6 speed except for the clutch combinations it uses to get the 6th gear. Is it possible to convert the 5 speed to a 6 by changing the electronics?

From what I have read it is possible. Talk to Mike L. at Inglewood transmissions or Eric at Merchant Auto. Both of these guys have web sites. Mike is in Southern California and Eric is in Michigan. You can check out the Suncoast web site for details as well. LOL

http://www.inglewoodtransmission.com/

http://www.gmdieseltech.com/store2/

http://www.suncoastconverters.com/gmc/gm_products.html

Click on LCT 1000, then click on components. You will see the kit in the upper right.

Flash2004 · November 20, 2007

I have an 01 2500 HD LB7 with a 5 speed allison trans. Internally this trans seems to be the same as the 6 speed except for the clutch combinations it uses to get the 6th gear. Is it possible to convert the 5 speed to a 6 by changing the electronics?

From what I have read it is possible. Talk to Mike L. at Inglewood transmissions or Eric at Merchant Auto. Both of these guys have web sites. Mike is in Southern California and Eric is in Michigan. You can check out the Suncoast web site for details as well. LOL

http://www.inglewoodtransmission.com/

http://www.gmdieseltech.com/store2/

http://www.suncoastconverters.com/gmc/gm_products.html

Click on LCT 1000, then click on components. You will see the kit in the upper right.

That's good help, thanks and I have bookmarked those pages for the future. Disappointingly the extra gear is an overdrive and my 8.1 struggles to pull top gear at 60mph (about 1900rpm) as it is with the bigger tires fitted and its slow to kick down back to 3rd when overtaking. So I won't be taking that option. Our roads here are usually narrow and winding and passing opportunities limited. cheers