• 258mm LU (4L60-E, 5L40-E)
• 258mm LU (4T65-E)
• 265mm LU (4T60-E, 4T80-E)
• 4L80-E (Dual Stator)

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• 280mm LU (4L60-E) “VJCX”
• 300mm (4L60-E)
• 4L80-E (Late Single Stator)
• 6L80, 6L90 (300mm)
• 6L80, 6L90 (300mm)

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• TH400
• For use with frictions about .060" thick.

Rubber separators can be used in GM TH400 racing transmissions to help keep clutch steels separated and reduce open clutch drag when the clutch is disengaged. Fric...Read More

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• 4L60-E
• 4L65-E
• 4L70-E
• Fits '94-later units.

The Sonnax Performance Pack for GM 4L60-E, 4L65-E and 4L70-E transmissions is a must-have for any heavy-duty vehicle and the very best foundation for high-performa...Read More

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• 4L60-E
• 4L65-E
• 4L70-E
• Early style

Line pressure booster kit 4L60E-LB1 fits early-style GM 4L60-E, 4L65-E and 4L70-E pumps. Sonnax hydraulic line pressure booster kits contain stronger pressure regu...Read More

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• 4L60-E
• 4L65-E
• 4L70-E
• Late style

Line pressure booster kit 4L60E-LB2 fits late-style GM 4L60-E, 4L65-E and 4L70-E pumps. Sonnax hydraulic line pressure booster kits contain stronger pressure regul...Read More

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• 4L60-E
• 4L65-E
• 4L70-E
• Fully compatible with '95-later with PWM/EC3 (electronically controlled capacity clutch) control.

Sonnax Sure Cure kit SC-4L60E is a comprehensive reconditioning package for GM 4L60-E, 4L65-E and 4L70-E PWM units featuring the best Sonnax products developed to ...Read More

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• 4L80-E
• Short Version, Retrofits ’95-later detent levers to early ’91–’94 units without external NSS.

Sonnax manual shift shaft kit 38511-03K for the GM 4L80-E is an early model ’91–’94 manual shift shaft that retrofits to a late-model ’95-later manual shaft detent...Read More

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• 4L80-E
• 4L85-E
• Fits late style, gray connector

It is common for one of the three plastic retention tabs to break on the wiring harness case pass-through connector in GM 4L80-E and 4L85-E units. This allows the ...Read More

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• 4L60-E
• 4L80-E
• 4L85-E

Transmission cases made in 1994 and 1995 have neutral safety switch mounting holes but do not have the top mount shifter bracket holes. Sonnax shift cable mount br...Read More

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• 4L80-E
• '91–'94 Without external NSS, short version

Manual shift shafts in GM 4L80-E can become corroded in harsh environments. Corroded manual shift shafts are not suitable for reuse, especially in remanufacturing....Read More

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• 4L80-E
• 4L85-E

GM 4L80-E and 4L85-E forward drums are often replaced due to wear of the sealing ring bore caused by contact with the input shaft. Contact between shaft and drum o...Read More

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• 4L80-E
• 4L85-E

The actuator feed limit (AFL) valve in GM 4L80-E and 4L85-E units has a large reaction area and is greatly affected by side loading, which wears the valve body bor...Read More

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• 4L80-E
• 4L85-E
• Fits units '95-later.

Vehicles with '95-later GM 4L80-E and 4L85-E transmissions commonly exhibit wear in the Reverse checkball sleeve located in the 3-4 shift valve bore. This issue is...Read More

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• 4L80-E
• 4L85-E
• Fits units '95-later.

Vehicles with '95-later GM 4L80-E and 4L85-E transmissions commonly exhibit wear in the Reverse checkball sleeve located in the 3-4 shift valve bore. This issue is...Read More

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• 4L80-E
• 4L85-E
• Long version, fits ’95-later with external NSS.

Manual shift shafts in GM 4L80-E and 4L85-E models can become corroded in harsh environments. Corroded manual shift shafts are not suitable for reuse, especially i...Read More

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• 4L80-E
• 4L85-E

GM 4L80-E and 4L85-E transmissions may have 2nd gear starts and no upshifts, which can be accompanied by trouble codes 68, 85, 86 and/or 87. These problems can oft...Read More

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• 4L80-E
• 4L85-E

In 4th Gear, signal A oil force must overpower the 1-2 shift valve spring and opposing signal B pressure in GM 4L80-E and 4L85-E transmissions. If the 1-2 shift va...Read More

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• 4L80-E
• 4L85-E

GM vehicles equipped with 4L80-E and 4L85-E transmissions may exhibit problems such as TCC shudder, burnt converter linings, TCC apply and release concerns and rel...Read More

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• 4L80-E
• 4L85-E
• Fits '91-later units with factory-style sleeve, no O-rings. Can be retrofitted to '89–91 units. See instructions for details.

Common problems in vehicles with GM 4L80-E and 4L85-E transmissions are uncontrollable line rise (upward of 500-600 psi), high line pressure in Reverse, buzzing no...Read More

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• 4L80-E
• 4L85-E

GM 4L80-E and 4L85-E units may display no converter lockup or codes 68, 39, 1870 or P0741. Imbalance of torque converter clutch apply oil through the front stator ...Read More

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• 4L80-E
• 4L85-E
• With encapsulated relief valve. O-Ring style

Common problems in vehicles with GM 4L80-E and 4L85-E transmissions include uncontrollable line rise (upward of 500 psi), high line pressure in Reverse, broken dir...Read More

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• 4L80-E
• 4L85-E
• O-Ring style. Kit can be retrofit to back to '89 units. See instructions for details.

Common problems in vehicles with GM 4L80-E and 4L85-E transmissions are uncontrollable line rise (upward of 500-600 psi), high line pressure in Reverse, buzzing no...Read More

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• 4L80-E
• 4L85-E

GM vehicles equipped with 4L80-E and 4L85-E transmissions may exhibit problems such as TCC shudder, burnt converter linings, TCC apply and release concerns and rel...Read More

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• 4L80-E
• 4L85-E
• TH400
• Updated 3-tang style shim fits all units, including '97-later 4L80-E and 4L85-E units.

It is often difficult to reduce front unit endplay on GM TH400 or 4L80-E and 4L85-E units with excessive spline wear. Normal component wear allows excess forward a...Read More

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