Fits General Motors 4L80E and 4L85E 1991-2009

Includes Modulator Canister, "Modulator bushing and valve", Modulator pin, Resistor, Pressure Regulator spring and items necessary to utilize vacuum for pressure rise.

Replaces PCS/EPC (Pressure Control Solenoid) for Heavy Duty, High Performance and No Computer, Great for transplants. Kit allows for control of Pressure Rise with vacuum instead of vehicle PCM controlling PCS/EPC Solenoid. This kit is included with the 4L80E-3 Stick Shift Kit. 

Notice: 48-MOD kit does not shift the transmission through its gear ranges, it utilizes the manifold vacuum signal from the engine to raise and lower transmission pressure as needed for proper clutch and band holding capacity during up shifts and downshifts.

NOTE: Does Not fit Diesel

Installation recommendation: Experienced technician
Transmission removal necessary: No

Pressure Regulator Valve 4T40E Oversized

• Valve is hard-coat anodized to reduce wear.
• Additional spool with flats at the decrease circuit provides additional valve stability and prevents line pressure leakage.
• One valve works in both the early and late OE applications

3-4 Accumulator Piston

It is common to have poor 3-4 shifts, no 4th gear or a burned 4th clutch in 4T65-E units. This can be caused by excessive wear at the 3-4 accumulator piston pin bore, which allows 4th clutch oil to exhaust and can result in harsh 4th, no 4th gear or a burned 4th clutch. Pin bore wear also reduces 3rd clutch pressure during 3-4 shift. The 4th shift quality depends on the condition of the piston and accumulator valves. If the 4th accumulator piston seizes, the 4th shift will be very hard. The accumulator piston 84880M-01 restores accumulator pressure and eliminates cross leaks.

Symptoms:
3-4 Concerns
4th Clutch burned
No 4th
Soft 3rd

Cause:

Wear at the 3-4 accumulator piston pin or bore.

Correction:

The Sonnax piston is made from high grade billet aluminum to prevent wear and restores clearances at the pin.

Accumulator valve 2-3 4T65E

• Valve 
• Sleeve 

Fits GM units only.

To help control the 3rd clutch apply pressure and shift feel, a 2-3 accumulator piston and an accumulator valve and sleeve that regulate fluid pressure are used. The 2-3 accumulator valve and sleeve regulate line pressure using torque signal influence and direct 2-3 accumulator pressure to the spring side of the piston, controlling the 3rd clutch apply. Wear at the sleeve or valve can allow torque signal, 2-3 accumulator or line pressures to exhaust, resulting in various 2-3 shift complaints. Some early OE valves were not anodized, and are prone to significant wear and scratching.

Symptoms:

2-3 Shift concerns
Low line rise

Cause:

Wear of the 2-3 accumulator valve and/or sleeve allow loss of torque signal, 2-3 accumulator and/or line pressure.

Correction:

Install the Sonnax valve and sleeve kit that has upgraded materials, restores correct hydraulic clearances and is designed to prevent wear.

NOTE: For 4T65-E units installed in Volvo vehicles, use 2-3 accumulator valve kit 84754-64K.

Accumulator pin kit 4T65E

• Pins (10)
• Reamer 

Inconsistent shifts, high shift adapt numbers and burned clutches in a 4T65-E can all be traced back to worn accumulator pistons. Pin bore wear allows clutch apply pressure to exhaust into accumulator circuits and decrease clutch apply pressure.

Symptoms:

Burnt clutches
High shift adapt numbers
Inconsistent shift quality

Cause:

Worn 1-2 and 2-3 accumulator piston pin bore

Correction:

This oversized replacement accumulator pin restores the proper fit between the piston and the bore and allows re-use of the original aluminum piston.

Reverse & Modulated line boost valve kit

• Modulated Line Boost Valve 
• Modulated Line Boost Sleeve 
• Modulated Line Boost Spring 
• Reverse Boost Valve 
• Reverse Boost Sleeve 
• Reverse Boost Spring 

High Ratio

Vehicles with 4T60 or 4T60-E transmissions often exhibit problems as poor line rise, soft shifts, poor reverse boost, and/or 2nd and 3rd clutch distress. These problems are often caused by worn and leaking boost sleeves.

Symptoms:

2nd Clutch distress
3rd Clutch distress
Low line rise
Low Reverse boost
Soft shifts

Cause:

Worn and leaking boost sleeves

Correction:

These replacement boost valve kits provide more sealing area. Sleeves and valves made from high-quality hardened steel to prevent excessive wear.

Boostvalve 4T60E

• Valve
• Sleeve
• Spring

Low Ratio, .276 dia. small spool

Vehicles with 4T60E or 4T60-E transmissions often exhibit problems as poor line rise, soft shifts, poor reverse boost and/or 2nd and 3rd clutch distress. These problems are often caused by worn and leaking boost sleeves. 

Symptoms: 

• 2nd Clutch distress
• 3rd Clutch distress
• Low line rise
• Soft shifts

Cause:

Worn and leaking boost sleeves

Correction:

This replacement boost valve kit provides more sealing area. Sleeves and valves made from high-quality hardened steel to prevent excessive wear.

Modulated line boost valve kit

High Ratio, .199" dia. small spool

Vehicles with 4T60 or 4T60-E transmissions often exhibit problems as poor line rise, soft shifts, poor reverse boost, and/or 2nd and 3rd clutch distress. These problems are often caused by worn and leaking boost sleeves.

 Symptoms:

2nd Clutch distress
3rd Clutch distress
Low line rise
Soft shifts

Cause:

Worn and leaking boost sleeves

Correction:

This boost valve kit provides more sealing area. Sleeves and valves made from high-quality hardened steel to prevent excessive wear.

Line Pressure Booster Kit

Part No. 4T65E-LB1

•Large Ratio Boost Assembly
•Pressure Regulator Spring

Sonnax hydraulic line pressure booster kits contain stronger pressure regulator
springs and large ratio boost valves designed to work together to provide
progressive pressure increases as driving conditions become more demanding.

These pressure regulator springs are approximately 10% stronger than OE and
more conservative in impact than other aftermarket kit springs. Large ratio boost
valves provide higher pressure incrementally and when it is needed the most.
The combination of these springs and valves in a Sonnax kit gives you the best
of both worlds: a modest pressure increase at the low end, with a high-end
pressure that is equal to or greater than that of other aftermarket kit springs.

•Achieve shorter shifts and increased torque capacity without creating low-speed harshness
•Improved band and clutch holding capacity for increased durability
•Progressive pressure increase as driving conditions become more demanding
•All the benefits of increased line pressure without overloading the pump at idle
•Simple and affordable drop-in solution with no special tools or reaming required

Reverse boostvalve 4T60E

Low ratio, .273 dia. small spool

Vehicles with 4T60 or 4T60-E often exhibit problems as poor line rise, soft shift, poor reverse boost and/or 2nd and 3rd clutch distress. These problems are often caused by worn and leaking boost sleeves. 

Symptoms:

Low Reverse boost

Cause:

Worn and leaking boost sleeves

Correction: This boost valve kit provides more sealing area. Sleeves and valves made from high-quality hardened steel to prevent excessive wear.

Side cover repair plate

For stamped steel side covers

Vehicles with a 4T60 or 4T60-E transmission often have oil leakage at the side cover to channel plate inner gasket. The time-consuming and difficult task of replacing the inner side cover gasket often does not eliminate the leakage. The failure of this gasket can be caused by 4th clutch heat, side cover corrosion, and/or potential crushing or splitting of the gasket when the side cover pan nuts are torqued. We offer a leak repair plate, 84995-01, designed to fix the leak without removing the side cover or replacing the failed gasket.

Symptoms:

Leakage of oil at side cover to channel plate inner gasket

Cause:

4th clutch heat, side cover corrosion, crushing or splitting of the gasket when the side cover pan nuts are torqued.

Correction:

Fix the leak without removing the side-cover or replacing the failed gasket with this leak repair plate.

NOTE: For use with stamped steel side cover.