Rostra Precision Controls 63-0039 TH700-R4 4L60 Internal Wire Harness with TCC Lock-Up Solenoid

The Rostra Precision Controls 63-0039 (also known as 350-0039) is an internal wire harness assembly with integrated torque converter clutch (TCC) lock-up solenoid designed for General Motors TH700-R4 and 4L60 automatic transmissions. This complete replacement assembly restores proper torque converter clutch function, ensuring smooth lockup operation in higher gears.

Key Features:

• Complete internal wire harness with integrated TCC lock-up solenoid
• 3-pin connector configuration for direct installation
• Orange Type 18 solenoid design
• Direct replacement for GM OEM part number 10478100
• Precision-engineered to OEM specifications for reliable performance
• ISO 9001/TS 16949 certified manufacturing quality

Applications:

• GM TH700-R4 transmissions (1982-1992)
• GM 4L60 transmissions (1982-1993)
• Compatible with various GM trucks, SUVs, and performance vehicles including Camaro, Firebird, Corvette, and Silverado models

Cross-Reference Numbers:

• OEM: 10478100
• Industry: 77949N
• Transtar: 74425L
• WIT: 74425L
• Natpro: 51870L

This harness assembly eliminates common transmission issues such as high highway RPMs, excessive heat buildup, sluggish acceleration, and poor fuel economy caused by failed lock-up solenoids. Installation is straightforward during transmission service or rebuild—no cutting, splicing, or special tools required. Rostra Precision Controls brings nearly 150 years of precision manufacturing expertise to deliver aftermarket transmission components trusted by professional technicians and enthusiasts alike.