Speedo Cable Adapter GM

The Speedo Cable Adapter GM from AutoMeter is a precision speedometer cable extension designed for General Motors vehicles requiring a reliable connection between the transmission output shaft and the speedometer head. This adapter solves common cable routing challenges and shaft misalignment issues that arise when upgrading gauges, relocating instrument clusters, or installing aftermarket speedometer systems. Whether you're performing a classic car restoration, modernizing a vintage GM platform, or troubleshooting cable tension problems, this adapter ensures accurate speed readings without the need for complete cable replacement.

Constructed from durable steel, the Speedo Cable Adapter GM features a 5/8-18 inch cable thread specification, the industry standard for GM speedometer applications. The adapter includes an integral cable extension, allowing flexible installation geometry and eliminating the need for separate extension purchases. Its compact 2.5 x 1.25 x 4 inch footprint makes it ideal for tight engine bay layouts, while the threaded connection ensures secure, vibration-resistant mounting. The steel construction provides long-term corrosion resistance and reliable torque retention, critical for maintaining signal integrity during vehicle operation.

This adapter is essential for GM platform enthusiasts, restoration specialists, and technicians working with vehicles spanning multiple decades of GM transmission and speedometer evolution. Installation requires basic hand tools and takes minutes, making it accessible for both professional shops and experienced DIY builders. Compatible with GM transmission outputs using 5/8-18 threading, the included cable extension accommodates non-standard routing paths common in modified or relocated gauge installations. For anyone replacing a worn speedometer cable or upgrading to modern electronic instrumentation on a classic or vintage GM vehicle, this adapter delivers OEM-quality performance at a fraction of replacement cable costs.