Transmission Parts

Boost Valve Kit 4L80-E, 4L85-E From Sonnax Compatible with '91-later units featuring a factory-style sleeve (no O-rings). Can also be retrofitted t...

Sonnax 1-2 And 2-3 Shift Valve Spring Kit for 4L80-E, 4L85-E In GM 4L80-E and 4L85-E transmissions, proper 4th gear operation relies on signal A oi...

Sonnax Boost Valve Kit for 4L80-E, 4L85-E GM 4L80-E and 4L85-E transmissions often encounter issues like uncontrollable line rise (up to 500-600 ps...

Sonnax TCC Regulator Valve Kit for 4L80E and 4L85E Transmissions GM vehicles equipped with 4L80-E and 4L85-E transmissions may experience issues su...

Sonnax Zip Kit for 6R60, 6R75, 6R80 , ZF6HP19, ZF6HP26, ZF6HP32 The Sonnax Zip Kit ZF6-6R60-ZIP addresses common valve body issues in ZF6HP19/26/32...

Pinion Bronze Washer Kit (6) Sonnax Sun Gear 24 tooth 5R55N 5R55S 5R55W Fits .452in dia. pinion pins. For OD planetaries with 24-tooth sun gear Tra...

Sonnax Shift Cable Mount Bracket 4L60E 1996/97 4L80E 4L85E 1996 Transmission cases made in 1994 and 1995 have neutral safety switch mounting holes ...

Sonnax Sure Cure Kit for 4L80E And 4L85E Rebuild with confidence and stop "comebacks" with the Sonnax Sure Cure Kit (SC-4L80E). The 4L80E is a heav...

Sonnax Case Saver Retainer for TH400 & '98-Earlier 4L80-E The Sonnax case saver retainer 34762-10 is the only intermediate clutch retaining rin...

Sonnax Planetary Rebuild Kit for 4L80-E, TH400 Transmissions Optimize the performance of your TH400 or '98-earlier 4L80-E transmission with the Son...