⚙️ Twisted Pro™ C5 Corvette 4L60E Performance Transmission

550 HP Rated | 1997–2004 C5 Corvette

5.7L LS1 • Automatic Corvette Applications

Heads & Cam • Modified LS1 • Street Performance • Mild Power Adders

The Twisted Pro™ C5 Corvette 4L60E is our 550 HP build for modified automatic C5 Corvettes.

The Pro steps up from our Street build with increased 3-4 clutch capacity, input housing reinforcement, 5-pinion planetary gearsets, Sonnax SmartShell, Super Hold servos, an extra-wide performance band and TransGo 4L60E-HD2 valve body updates.

Rated up to 550 HP.

🔧 TWISTED PRO™ INTERNAL BUILD

✔️ Performance Frictions

New performance friction plates throughout.

✔️ New Steels

New steel plates throughout.

✔️ High-Capacity 3-4 Clutch Pack

Increased 3-4 clutch capacity over the stock configuration.

✔️ Heavy-Duty 3-4 Backing Plate

The 3-4 clutch pack is set up with a heavy-duty backing plate. Clutch stack and clearance are checked and set during assembly.

✔️ Extra-Wide Performance 2-4 Band

Increased holding area in 2nd and 4th gear.

✔️ New Forward Sprag

✔️ New Bushing Set

✔️ Bearings & Thrust Washers

Inspected and replaced as required.

✔️ New Transmission Filter

🔩 INPUT HOUSING REINFORCEMENT

✔️ Sonnax Input Housing Overrun Sleeve

The input housing is checked for cracking, spline wear and damage before being reinforced at the input-shaft / overrun area.

🐚 SONNAX SMARTSHELL

✔️ Sonnax SmartShell Heavy-Duty Reaction Shell

The stock-style reaction shell is replaced with a Sonnax SmartShell.

🔩 5-PINION PLANETARY GEARSETS

✔️ 5-Pinion Forward Planetary

✔️ 5-Pinion Rear Planetary

The Pro gets the stronger later-style 5-pinion forward and rear planetary gearsets.

⚙️ SONNAX SUPER HOLD SERVOS

✔️ Sonnax Super Hold 2nd Servo

✔️ Sonnax Super Hold 4th Servo

Paired with the extra-wide 2-4 band for increased holding in 2nd and 4th gear.

⚙️ TRANSGO 4L60E-HD2 VALVE BODY

✔️ TransGo 4L60E-HD2 Reprogramming Kit

The valve body is completely cleaned, checked and updated.

Includes updates for:

✔️ Pressure Regulator Circuit

✔️ Boost Pressure

✔️ 2-3 Shift

✔️ 3-4 Clutch Apply

✔️ 2-4 Band Apply

✔️ TCC Apply / Release

✔️ Converter Charge

✔️ Accumulator Circuits

✔️ Heavy-Duty 2-3 Shift Valve

Set up for firm, positive performance shifts without unnecessary harshness.

⚡ SOLENOIDS & INTERNAL ELECTRONICS

✔️ Shift Solenoids Tested

✔️ EPC / Pressure Control Solenoid Tested

✔️ TCC Solenoid Tested

✔️ Internal Harness Inspected

⚙️ TWISTED PRO™ 4L60E PUMP

✔️ Pump Body & Stator Inspected

✔️ New Pump Bushing

✔️ Rear Stator Support Bushing Updated

✔️ Pump Rotor & Vanes Inspected

✔️ Pump Rings Inspected

✔️ Pump Slide Inspected

✔️ Pump Clearances Reset

✔️ Pressure Regulator Circuit Corrected

✔️ Boost Valve Updated

✔️ Performance Pump Slide Spring

✔️ Converter Feed / Charge Circuit Checked

✔️ TCC Circuit Checked & Corrected

🔩 HARD PART INSPECTION

All remaining reusable hard parts are cleaned and checked before assembly.

✔️ Input Shaft

✔️ Input Housing

✔️ Forward Clutch Housing

✔️ Reverse Input Drum

✔️ Reaction Shaft

✔️ Input Sprag

✔️ Corvette Output Shaft

Anything worn, cracked, damaged or out of specification is replaced.

🚙 C5 CORVETTE TORQUE CONVERTER INCLUDED

✔️ 1800–2100 Stall Heavy-Duty Lockup Torque Converter

Higher-Stall & Billet Converter Upgrades Available

🏁 BUILT FOR

✔️ Modified LS1 Corvettes

✔️ Heads & Cam Combinations

✔️ Bolt-On Performance Builds

✔️ High-Output Naturally Aspirated Builds

✔️ Mild Power-Adder Applications

✔️ Street Performance

✔️ Up To 550 HP

For combinations making more than 550 HP, move up to the Twisted Punisher™.

🛠️ C5 CORVETTE APPLICATIONS

1997–2004 Chevrolet Corvette

5.7L LS1

Automatic Transmission • RPO M30

The C5 uses a rear-mounted 4L60E connected to the engine through the torque tube.

Year and transmission configuration must be verified before ordering.

❌ C5 Z06

The C5 Z06 was not offered with the 4L60E automatic.

⚠️ TORQUE TUBE & DRIVELINE INSPECTION

While the transmission is out, inspect:

✔️ Torque Tube & Bearings

✔️ Driveshaft / Couplers

✔️ Flexplate

✔️ Differential Mounts

✔️ Transmission Mounts

✔️ Cooler & Cooler Lines

🧊 COOLER REQUIREMENT

A properly functioning transmission cooler is required.

The cooler and cooler lines must be flushed and checked for unrestricted flow before installation.

If the previous transmission contaminated the cooler with clutch material or metal, replace the contaminated cooler.

C5 +3.5-Quart Deep Aluminum Cooling Pan - HIGHLY RECOMMENDED

Available as an optional upgrade.

⚙️ TWISTED PRO™ C5 CORVETTE 4L60E

550 HP RATED

HIGH-CAPACITY 3-4 • 5-PINION GEARTRAIN • SONNAX SMARTSHELL

INPUT HOUSING REINFORCEMENT • SUPER HOLD SERVOS • EXTRA-WIDE BAND • TRANSGO 4L60E-HD2

1800–2100 Stall Heavy-Duty Lockup Converter Included

Heads & Cam • Modified LS1 • Street Performance • Mild Power Adders

Built Tough. Built Twisted.™