GM 6L80, 6L90
Performance Transmission Upgrades

The GM 6L80/90 series is one of the most common units on the road and in shops for repair. Hard-working commercial applications and popular performance applications can push this unit to the limits. Sonnax offers an extensive range of products to enhance any build, from tuning pressure and restoring valve body function to ramping up shaft and clutch durability.


The GM 6L80/90 series is one of the most common units on the road and in shops for repair. Hard-working commercial applications and popular performance applications can push this unit to the limits. Sonnax offers an extensive range of products to enhance any build, from tuning pressure and restoring valve body function to ramping up shaft and clutch durability.

Transmission Upgrades All Transmission Parts Request HD Work/Sport Catalog

View Performance Parts by Application:

Sonnax has the best products in our industry that we know we can trust. We always use your products.

Bowler Performance Transmissions
66L45, 6L50, 6L80, 6L90 Line Pressure Booster Kit

Line Pressure Booster Kit

Improve Shift Feel & Durability
Heavy & Extreme Duty 4-5-6 Clutch Hub & Intermediate Shafts

Heavy & Extreme Duty 4-5-6 Clutch Hub & Intermediate Shafts

Heavy Duty to Increase Durability Without Sacrificing Drivability, Extreme Duty to Maximize Durability & Clutch Capacity
6L45, 6L50, 6L80, 6L90 Zip Kit

Zip Kit®

Drop-In Valve Body Repairs for Improved Performance
Multi-Plate Converter Clutch Kits

Performance Converter Kits

Increase Torque Capacity & Performance
6L80, 6L90 Heavy Duty 1-2-3-4 Piston

Heavy Duty 1-2-3-4 Piston

Prevent Failure with a High-Strength Billet Piston

The best performance parts in the world: Sonnax.

Donovan R.

6L80, 6L90 Performance Upgrades

Use this chart to get maximum results out of your 6L80/90 series rebuild and find the parts you need to enhance different areas of the transmission.

Sonnax offers parts for 3 different levels of performance:

LEVEL 1

LEVEL 2
Bolt-On Performance & Mild Tuning

LEVEL 3
Extensive Engine/Tuning Mods and/or Power Adder

Level 1 Level 2 Level 3
Area of Enhancement Part Name Part Number Stock Vehicle Stock/Heavy-Duty
Commercial Vehicle		 Bolt-On Performance & Mild Tuning Extensive Engine/Tuning Mods
and/or Power Adder
4-5-6 Clutch Heavy Duty 4-5-6 Clutch Apply Piston Kit 104960-01K ✓1A & 1B OE clutch configuration
Heavy Duty 4-5-6 Clutch Hub & Intermediate Shaft 104680-36 ✓1A & 1B 6L80 ✓1A, 1B & 2 6L80
Heavy Duty 4-5-6 Clutch Hub & Intermediate Shaft 104690-36 ✓1A & 1B 6L90 ✓1A, 1B & 2 6L90
High Capacity 4-5-6 Clutch Apply Piston Kit 104960-10K ✓2 No wave plate,
Add one OE-style friction
Extreme Duty 4-5-6 Clutch Hub & Intermediate Shaft 104680-45 ✓3 6L80
Extreme Duty 4-5-6 Clutch Hub & Intermediate Shaft 104690-45 ✓3 6L90
High Capacity 4-5-6 Clutch Apply Piston Kit 104960-20K ✓3 No wave plate,
Powerglide-style frictions
4-5-6 Clutch Friction (Powerglide Style) 104120-03 ✓3
4-5-6 Clutch Steel (.078") 104120-01 ✓3
4-5-6 Clutch Steel (.090") 104120-02 ✓3
3-5-R Clutch High Capacity 3-5-R Apply Ring 104548-01 ✓ 6L802 & 3 6L80No wave plate,
Add one OE-style friction		 ✓ 6L80 No wave plate,
Add one OE-style friction
1-2-3-4 Clutch Heavy Duty 1-2-3-4 Piston 104984-01 ✓1A, 1B, 2, 3 ✓ ✓
Line Pressure Line Pressure Booster Kit 6L80-LB1 ✓1A, 1B, 2 & 3 ✓ ✓
Pump Slide Spring 104534-HD ✓2 & 3 ✓

Learn More

This video covers four popular parts: the heavy-duty 4-5-6 clutch apply piston kit, high-strength pump slide spring and award-winning line pressure booster kit and Zip Kit®.


 

Your stellar products are used every day in my shop in every build, and you are hands down the best in the business!!!! Thank you for being an industry leader and developing great products.

Scott T.

Sonnax high performance products meet the toughest challenges faced by hard-working, daily-use drivetrains as well as racing units going all-out on the street or track.

Learn About Sonnax Heavy Duty & High Performance See All Heavy Duty & High Performance Upgrades
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