Fits: 2011 thru 2016 Chevy Silverado/GMC Sierra 2500HD/3500HD LML Duramax Diesel

SunCoast Category 4 kits offer the same recipes as their in house builds that have been proven for years both at the track and on the road. This rebuild kit includes everything you will need to build your Allison the same way SunCoast builds them in house, including detailed instructions that will walk you through each step of the process. These kits utilize the latest proven friction materials and steel technology from industry leading companies such as Alto and Raybestos. This kit is best suited for daily driver/tow/street/strip/sled pulling applications with extensive modifications done to the truck.

Includes:

• Custom clutches & steel
  
• Custom billet plates
• Custom overhaul kit
• Valvebody calibration kit
• Gasket kit
• Internal Filter
• Spin on filter
• Pan gasket
• SunCoast Filter "Loc"
  
• New internal wiring harness
• Billet C2 Clutch Hub
• Modified Sun Gear
• Billet P2 Planetary Assembly
• Billet SFI certified Flexplate
• Billet Input Shaft
• Billet Intermediate Shaft
• Billet Output Shaft
  

Kit Features:

• SunCoast proprietary C1, C2, C3, and C4 Alto carbonite frictions/Raybestos SCZ frictions that contain no center slots
• Frictions utilize a waffle pattern in the material to help retain oil helping the clutch cool when not applied
• Redesigned apply pistons with improved rubber compounds proven to hold higher heat
• Allows use of thicker spring apply plate which replaces the thin OEM one that will cone & cause uneven apply surface resulting in premature clutch failure
• Custom SunCoast apply plate that redirects fluid to better lubricate frictions from the inside out which lubes the entire friction rather than OEM style that lubricates from the center out leaving the inner half of the clutch burnt
  
• Includes exclusive smart trim/clutch control valve
• Includes all items needed to modify the C2 clutch piston for increased clutch durability

Flexplate:

This SunCoast Allison billet SFI certified billet flexplate replaces the factory flex plate with an improved billet steel one piece design, eliminating the weak factory flex plate. A must for high torque in conjunction with a better designed torque converter that can transfer torque with no slip. This one piece billet flex plate is SFI certified to 29.3.

Input Shaft:

The input shaft is the first thing to go south in the Allison transmission. This billet input shaft is built to withstand everything you can throw at it. Manufactured from 9310 Vacumelt steel which increases torsional fatigue strength by over 50%. Also, the billet input shaft is machined with a larger radius at the turbine spline for added strength. This is a must for vehicles that are lifted with larger wheels and tires, heavy towing/hauling, and vehicles with aftermarket turbos.

C2 Hub:

The Allison transmission is an incredibly robust unit, however when exposed to conditions outside what it was designed for, weak points begin to expose themselves. The factory C2 clutch hub has been known to fail prematurely. Most commonly seen in conditions where larger tire/wheel combinations, heavy towing/hauling, sled pulling, drag racing, and larger shock loads. SunCoast uses a much stronger billet piece manufactured from 4140 heat treated stress relieved steel, spline lengthened .125" for increased contact area and spline boss diameter increased .100" for added strength. 

P2 Planet:

The P2 planet in the Allison transmission can strip or snap as a result of poor tuning, shock load, improperly built transmissions and/or high horsepower applications. This failure can and will result in catastrophic failure and immobility. The SunCoast P2 planet is manufactured using 4140 billet steel and then induction hardened. Highly recommended for higher horsepower applications, sled pulling, drag racing, as well as heavy duty towing. This planet comes with a machined sun gear which is required for use of the planetary.

Notes:

• Core charge is for torque converter, sun gear & P2 planet
  
• C5 clutches are not included
  
• Photos may not depict actual products included in kit