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SKU #: DT-6SPEEDKIT Duramax Tuner 6 Speed Conversion Kit 01-05 6.6L GM Duramax

Purchase Duramax Tuner 6 Speed Conversion Kit 01-05 6.6L GM Duramax
    • 2001-2005 6.6L GM Duramax
  • Choose One: Core Charge: ?

    Terms & Conditions

    We at Diesel Power Products offer a deferred core program in which we allow you to defer the typical upfront core charge when purchasing via credit card payment. All cores, whether the core charge was deferred or not, must be returned within 21 days from delivery date of product requiring core charge. Failure to do so can result in forfeiture of the entire core charge return. In the event you originally deferred the core charge, you authorize Diesel Power Products to charge you for the core charge.

    All cores must be returned to the original warehouse that original shipment was sent from. If a return label is provided in the original shipment, use this tag. If one is not included, contact us immediately, and we can provide you with the correct address of where the core(s) must be returned to, as well as an RMA (Return Merchandise Authorization) number. DO NOT rely on the return address on the original label as a source for where to ship to.

    If cores are shipped to the incorrect warehouse, your core money will be returned less the shipping cost for us to send the core(s) to the correct warehouse, or if you deferred the core you may be charged for the shipping amount.

    Cores that have been disassembled and/or have missing and/or damaged major components will not receive full core credit. Returned cores must be on a "like-for-like" basis, meaning that the returned core has the exact same fitment as the remanufactured component that was purchased. In the event that the core is not "like-for-like," your core may not be eligible for return / credit.

    Diesel Power Products has the right to alter this policy (i.e. extend the terms) for any reason. If you have an outstanding circumstance, contact us.

    What is a "Core Charge"?

    In order to understand what a core charge is, you must first understand what a core is. In the automotive industry, most products are manufactured from brand new materials. However, numerous products are also remanufactured, meaning that the manufacturer of the product takes a used product, typically removed from a vehicle, disassembles, and replaces all worn components of the master product. A great example of this is in regards to automatic transmissions in which the manufacturer takes an existing transmission, replaces all of the inner working components, such as the torque converter, valve body, etc. and merely reuses the case.

    Because aftermarket manufacturers require a steady stream of incoming cores to build, they charge a deposit on the core, known as a core charge, that is refunded upon receipt. In some cases, the core is not reusable, such as in the event of a cracked case, at which point the core deposit would not be credited as the core component is not reusable.

    If you plan on returning your core you have two options.

    OPTION 1:
    You can accept it, which means you will be charged for the part AND the core at time of purchase. You still have the option to send it back, and if you do, the core will be refunded back on the card used, presuming the core meets core criteria and the core is returned within 21 business days from originally receiving your order. If you have outstanding circumstances that would not allow the return to occur within 21 days, please contact us.

    OPTION 2 You can defer the core charge. If you defer it, you will not be charged a core at time of purchase. You will have 21 business days from the day you receive it to send it back. As long as the core is received within the 21 business days, you will not be charged. If 21 business days goes by and you do not send it back, the card on file will be charged the core amount. You still may send it back, and once received, we will issue the core amount as in store credit, pending any limitations as set forth by the manufacturer.Core deferral is limited to payment by credit card only.


Did you know that you can have 6th gear in your Allison transmission just like the later model Duramax's with a mere swap of the valve body and transmission control module (TCM)? Its true, you too ca ... read more

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Did you know that you can have 6th gear in your Allison transmission just like the later model Duramax's with a mere swap of the valve body and transmission control module (TCM)? Its true, you too can benefit from a double overdrive, resulting in better fuel economy, reduced wear on your engine, and a better overall driving experience with a simple upgrade.

Improve your LB7 or LLY's reliability by utilizing DuramaxTuner.com's own designed and tested kit coupled with their established transmission tuning. This is not merely a stock six speed Allison file, not even close! The tuning experts at Duramax Tuner calibrate both shift firmness and timing, so you'll be guaranteed to feel the smoothness and better shift quality missing on the 5 speed Allison. Furthermore, a huge benefit of adding another gear is that of the increased MPG's due to the reduction in RPM at cruising speed, which also reduces wear on critical engine components.

Overall, your truck will run smoother at higher speeds with less RPM, giving you a broader powerband, more fuel economy, and a more pleasurable driving experience.

IMPORTANT NOTE: This product requires an upfront core charge that will be reimbursed upon receipt of your original transmission control module. Once you have received and swapped out your original valve body and TCM, rebox the TCM into the 6 Speed Conversion Kit box and return to Duramax Tuner. Once they have received the TCM, they will notify us of the core return and we will promptly issue credit back to you. Because Duramax Tuner uses a brand new valve body, they have no need for you to return your original / core valve body, just the TCM.


  • ManufacturerDuramaxTuner.com
  • Includes Custom TCM Tuning
  • Double Ovedrive = 14% RPM Reduction
  • Includes New Valve Body, Wiring Harness, and Solenoids
  • Increased Fuel Economy
  • Reduced Powertrain Wear (Less RPM's)
  • Reduced Road Noise
  • Gear Indicator Works on Edge CTS Monitor
  • Works with High Idle, Retro Tap Shifters


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Duramax Tuner 6 Speed Conversion Kit 01-05 6.6L GM Duramax

Duramax Tuner 6 Speed Conversion Kit 01-05 6.6L GM Duramax

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