Description
Take your drivetrain to the next level with the Spool Performance Stage 2 DIY Transmission Kit for Dodge 8HP70 & 8HP75 — engineered to handle extreme power while maintaining smooth, OEM-like drivability.
After over a year of intensive testing and development, this kit was built to eliminate the common failure points found in factory 8HP transmissions. With a torque capacity exceeding 1200 ft-lbs, it transforms your transmission into a high-performance unit capable of handling aggressive builds, drag launches, and sustained high-load driving.
Unlike swapping to a larger transmission, this solution allows you to retain your existing 8HP70/75 while outperforming even the factory 8HP90 found in high-performance models — without the complexity of programming or retrofitting.
Advanced Engineering Breakdown
Billet 7075-T6 Hub Upgrade
Factory C and E hubs are made from weak A380 cast aluminum — a known failure point under high torque.
Spool replaces them with:
- Aerospace-grade 7075-T6 billet aluminum
- Heat-treated and hard-anodized construction
- Increased spline strength and wear resistance
Result: Eliminates cracking, spline failure, and clutch binding under extreme load.
FX-RT High-Performance Friction System
Developed in-house and proven across multiple high-torque platforms.
- Higher friction coefficient than OEM
- Superior heat resistance
- Consistent engagement without harsh shifting
- Designed for high-boost, nitrous, and high-RPM applications
Increased Clutch Capacity
Every clutch pack (A–E) is upgraded with:
- Additional friction discs
- Increased steel plates
- Improved clamping force
- Better thermal management
Outcome: More torque capacity, reduced heat, and longer transmission life.
Optimized Internal Design
- Improved oil flow and cooling paths
- Faster oil evacuation
- Increased clutch contact surface area
- Reduced rotating mass for quicker shifts
DIY-Friendly Installation
Built for enthusiasts and professional builders alike:
- Pre-clearanced clutch packs (ready to install)
- No machining required
- Includes extra steels for fine-tuning
- Direct drop-in compatibility with 8HP70 & 8HP75
If you’ve rebuilt a modern automatic transmission, this kit removes the guesswork and simplifies the process.
Features:
- FX-RT high-coefficient friction materials
- Billet 7075-T6 heat-treated hubs (C & E)
- Increased clutch counts across all packs
- Custom pressure and apply plates
- Pre-clearanced clutch packs
- Extra steel plates for tuning
- 1200+ ft-lbs torque capacity
- OEM-like drivability with extreme performance capability
What’s Included:
- 7075 Billet E Hub
- E Hub Center Bushing
- 7075 Billet C Hub
Clutch Packs:
- A Clutch: Frictions, Steels, Pressure Plate, Apply Plate
- B Clutch: Frictions, Steels, Pressure Plate, Apply Plate
- C Clutch: Frictions, Steels, Pressure Plate
- D Clutch: Frictions, Steels, Pressure Plate, Apply Plate
- E Clutch: Frictions, Steels, Pressure Plate
- Complete Seal Kit (Gaskets + O-rings)
Recommended Fluid:
AMSOIL Signature Series Fuel-Efficient 100% Synthetic ATF (Blue Cap)
FITMENT:
Compatible with Dodge / RAM / Jeep / Chrysler vehicles equipped with 8HP70 & 8HP75 transmissions
Dodge
- Charger R/T 5.7
- Charger Scat Pack / SRT 392 6.4
- Challenger R/T 5.7
- Challenger Scat Pack / SRT 392 6.4
- Durango R/T 5.7
- Durango SRT 6.4
RAM
- Ram 1500 5.7 (DT, 8HP75)
- Ram 1500 3.0 EcoDiesel
- Ram 2500 / 3500 6.4 (8HP75-LCV)
Jeep
- Grand Cherokee 5.7
- Grand Cherokee SRT 6.4
- Grand Cherokee 3.0 EcoDiesel
- Wrangler 392 6.4
- Wagoneer / Grand Wagoneer (8HP75 variants)
Chrysler
- 300C 5.7
- 300 SRT 6.4
Note: 'New' merchandise may be returned for exchange or refund within 15 days from the date of shipment. 'New' merchandise must be unused and free from installation or mounting damage. Installation or modification of parts waives your right to returns, refunds, or exchanges.
