Product Details

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This 4L80E Performance Reprogramming Kit fits 1991 to 2013 General Motors vehicles equipped with 4L80E and 4L85E automatic transmissions.  Common complaints on these transmissions are no upshifts, soft 2-3 shifts, burnt direct frictions, broken hard parts as well as gear ratio and solenoid performance codes.

The boost valve assembly is notorious for wear causing both low pressure as well as runaway boost pressure. With the low boost pressure problem, the resulting complaints are a soft 2-3 shift, direct clutch failure as well as the gear ratio and solenoid performance codes. On the other hand, the runaway boost pressure problem can result in a costly broken case, direct drum and piston failure.

Kit Features and benefits:

The TransGo 4L80E Performance Reprogramming Kit includes valve body, pump and internal components that are calibrated to work in concert with an elevated line pressure curve that will greatly improve the overall durability and shift feel of the transmission. Also, the laminated triple separator plate provides dual feed for the 3rd gear clutch without having to dismantle the transmission. Dual feeding the 3rd gear clutch triples the torque capacity of the 3rd gear clutch which is the Achilles heel of this transmission. In addition, the included highly improved wide land design boost valve and bushing resists wear so that pressure regulation functions consistently for the long haul. Lastly, the EPC boost pressure relief valve system provided helps protect against accidental runaway boost pressure to stop the case and direct drum failure.

Shift Kit Corrects, Prevents, Reduces:

• High pressure parts breakage
• Soft 2-3 shift
• Burnt direct clutch
• Slow 3-2 downshift
• No upshifts
• Harsh 1-2 shift
• Low pressure due to solenoid filter breakup
• Codes 39, 68, 85, 86, 87, P0731, P0732, P0733, P0734, P0751, P0756, P0894 and P1870

Shift Kit Includes:

• Heavy duty intermediate case snap ring
• (2) Accumulator valve springs, end plug and O-ring
• Actuator filter tapered plug, O-ring, spring and end plug
• Relief valve system plate, valve, spring, e-clip and nuts
• Laminated triple separator plate
• Valve body and accumulator body gaskets
• (2) Drill bits
• 3rd accumulator spring
• USA-made hardened boost valve and bushing
• Pressure regulator valve spacer, washer, springs and snap ring
• New stronger 4th feed bolt and washer
• 1-2 accumulator spring
• (16) Direct clutch return springs

The 4L80E and its variants were in production from 1991-2013 and can be identified by the 17-bolt oil pan and 4 forward gears.  Typically, this transmission is found in the heavier duty trucks and vans; mostly the 2500 and 3500 series.  It will also be found in the heavy half-ton, such as the 1500HD, SS, or Denali truck with the 6.0L

The 4L80E and 4L85E transmissions were found in the following GM labels and other brands; Chevrolet, Chevy, GMC, Hummer H1, Isuzu NPR, Jaguar, Aston Martin, Bentley, Rolls-Royce

These transmissions can be found in the following vehicles; however, you should double check your application with the 17-bolt pan count.  It is common for similar vehicles to have multiple transmission options available from the factory.

Chevrolet

• Avalanche 2500, 2002-2006
• Base Cab & Chassis, 2500, 3500, K2500, K3500, 1991-2009
• Express Van, 2500, 3500
• Silverado, Cheyenne, 2500, 3500, 2500 HD, K2500, K3500, 1991-2007
• Suburban, 2500 1996-2007
• Tahoe 6.0L, 8.1L 1995-2003

GMC

• Base Cab & Chassis, 2500, 3500, C2500, C3500, 1991-2009
• Savana Van, 2500, 3500
• Sierra, 2500, 3500, 2500HD, C2500, C3500, 1991-2007
• Yukon XL 6.0L, 8.1L 1995-2003

Hummer

• H1 1991-2005

Other

• Aston Martin DB7 1996-1999
• Bentley 1991-2006 (confirm 4-speed with 17 bolt pan)
• Isuzu NPR gas engine 1990-2007
• Jaguar XJS, XJS-R, XJ12 1993-1998
• Motor Homes 1995-2005
• Rolls-Royce 1992-2003

This transmission is part of the Turbo-Hydramatic series and also known by the following codes and model numbers: 4L80E, 4L80-E, MT1, 4L85E, 4L85-E, MN8

This shift kit fits the following years: 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, and 2013.