Drivetrain› Automatic Transmissions and Components

DuraMax Tuner

LLY (2004.5-2005) 6 SPEED DT750 BUILT TRANSMISSION W/TORQUE CONVERTER AND BILLET STATOR CORE CHARGE OF $1500 APPLIES

$9,009.00

SKU: D06C DT750-LLY-6SPEED-TQC

In Stock
In Stock
Ships by Jun 20
Free Shipping
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Description

This transmission package is designed to replace the stock transmission in 2004.5-2005 Chevy Silverado or GMC Sierra 2500HD/3500HD with the 6.6L LLY Duramax engine. It offers enhanced reliability for daily drivers and towing, featuring upgraded clutches, new electronics, an upgraded valve body with a TransGo Shift Kit, and a billet triple-disc torque converter. The 6-speed conversion provides improved fuel economy, reduced noise, and less vibration. It's designed to handle up to 1,400 HP and 2,000 ft-lbs of torque.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandDuraMax Tuner
Part NumberD06C DT750-LLY-6SPEED-TQC

Videos

Less Road Noise, Better Fuel Economy? The 6 Speed Conversion Kit Is What Your LB7 Or LLY Needs!

Less Road Noise, Better Fuel Economy? The 6 Speed Conversion Kit Is What Your LB7 Or LLY Needs!
Allison 5 to 6 speed conversion

Allison 5 to 6 speed conversion
I CAN'T BELIEVE THIS DURAMAX 6 SPEED CONVERSION MADE THIS MUCH OF A DIFFERENCE!!

I CAN'T BELIEVE THIS DURAMAX 6 SPEED CONVERSION MADE THIS MUCH OF A DIFFERENCE!!
We Need An Extra Gear - DIY 'Till I Die Ep. 4

We Need An Extra Gear - DIY 'Till I Die Ep. 4
2005 GMC Sierra 2500HD - Duramax Tuner 6 Speed Conversion

2005 GMC Sierra 2500HD - Duramax Tuner 6 Speed Conversion

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

View Full Return Policy