Product Details

Line pressure boost valve & spring kit for the 4L60E automatic transmission.

• Brand: Sonnax
• Part number: 4L60E-LB1
• Transmission models: 4L60E, 4L65E
• Makes: Buick, Cadillac, Chevrolet, GM, GMC, Hummer, Isuzu, Oldsmobile, Pontiac
• Year range: 1993-2005
• Product material: Billet aluminum
• O-ring style: Yes

Kit includes:

• Large ratio boost valve and sleeve assembly
• Stronger pressure regulator spring
• O-Rings – qty 2

The Sonnax pressure regulator springs are approximately 10% stronger than the OEM version and more conservative in impact than other aftermarket kit springs. Larger 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. Gives modest pressure increases at the low RPM, with a high-end pressure that is equal to or greater than that of other aftermarket valve and spring kits.

Kit features & benefits:

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

These transmissions can be found in the following vehicles; however, you should double check your application with the 16-bolt pan count. It is common for similar vehicles to have multiple transmission options available from the factory.

Buick

• Rainier, 2004-2005
• Roadmaster, 1994-1996

Cadillac

• Brougham, 1994-1997
• Escalade, EXT, ESV 1999-2005
• Fleetwood, 1994-1997

Chevrolet

• Astro Van, 1993-2005
• Avalanche, 2002-2005
• Blazer, 1993-2005
• C1500, some C2500, 1993-1999
• Camaro, 1994-2002
• Caprice, 1994-1996
• Corvette, 1994-2005
• Impala SS, 1994-1996
• S10, 1993-2004
• Silverado Truck, 1999-2005
• SSR, 2003-2005
• Suburban, 1993-2005
• Tahoe, 1993-2005
• Trailblazer, 2001-2005
• Van, 1994-2005

GMC

• Canyon, 2004-2005
• Colorado, 1994-2005
• Envoy - XUV – Denali, 2001-2005
• K1500, Some K2500, 1993-1999
• Safari Van, 1993-2005
• Sierra Truck, 1999-2005
• Sonoma, 1993-2004
• Van, 1994-2005
• Yukon, 1993-2005

Hummer

• H2, 2003-2005

Isuzu

• Ascender, 2003-2005
• Hombre, 1996-2000

Oldsmobile

• Bravada, 1993-2004

Pontiac

• Firebird & Trans Am, 1993-2002
• GTO, 2004-2005

This boost valve and spring kit fits the following years: 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, and 2005.

These transmissions are part of the Turbo-Hydramatic series and known as: 4L60E, 4L60-E, 4L65E, 4L65-E, 4L70E, 4L70-E, 4L75E, 4L75-E, M30, M32, M70