Jetuplusllc Transmission Kickdown/Detent Cable for 700R4 4L60 200-4R — K77978, 39.5" Conduit with 1.5" Adjustment

Jetuplusllc Transmission Detent Kickdown Cable K77978 is a direct-replacement kickdown/detent cable designed to fit GM 700R4, 4L60 and 200-4R automatic transmissions (select years), providing precise throttle-to-transmission linkage for smooth downshifts.

This replacement cable is new, OEM-style fitment engineered to restore correct kickdown function for many late‑20th-century GM automatics. It matches common interchange numbers and offers extra adjustment to help fine-tune shift timing without cutting or splicing. Before ordering, confirm your vehicle’s transmission model and year range—this cable does not fit the electronically controlled 4L60E.

Which transmissions and years does this cable fit?

This cable is intended for mechanical kickdown systems used on select GM transmissions. It fits 700R4, 4L60 and 200‑4R units within specific production years, helping ensure mechanical compatibility when replacing worn or damaged cables.

• 700R4: 1982–1993
• 4L60: 1987–1993
• 200‑4R (200R4): 1981–1990
• Not compatible with 4L60E (electronic control models)

How long is the cable and what adjustment does it allow?

The K77978 comes with a specifically sized outer conduit and inner wire length to match factory routing and movement. It includes extra adjustment to help achieve correct kickdown timing and clearances during installation.

• Outer conduit length: 39.5 inches
• Inner control wire length: 45 inches
• Additional adjustment available: 1.5 inches
• Direct-replacement design reduces the need for modification

What interchange numbers and part identifiers should I check?

Use interchange numbers to verify compatibility with your OEM part or existing cable. Matching one of these numbers helps ensure you receive the correct replacement component for your transmission setup.

• Manufacturer part number: K77978
• Interchange references: T54450C, K77978, M-T54450C, GM999C
• Fitment type: Direct replacement for compatible mechanical kickdown systems

How do I confirm this is the right cable for my vehicle?

Confirm the transmission model and production year on your vehicle, then compare lengths and part numbers to the original cable. If your transmission is electronically controlled (4L60E) this cable will not work.

• Verify transmission: 700R4, 4L60, or 200‑4R (not 4L60E)
• Measure original outer conduit and inner wire against listed lengths
• Cross-check OEM part number or interchange numbers
• Check routing clearance and available adjustment for installation

Who is this for: Technicians, DIY mechanics, restorers and classic GM owners who need a reliable mechanical detent/kickdown cable replacement for compatible 700R4, 4L60 or 200‑4R transmissions. This product is aimed at users seeking a direct-fit, new replacement part with factory-style lengths and modest extra adjustment to simplify installation and restore proper mechanical shift response.