Tachometer Gauge fits Massey Ferguson 255 40 20D 231 30E 50 20F 20E 250 40E 240 30H 298 1674638M92

What It Is

This is a replacement tachometer gauge that displays engine RPM for Massey Ferguson compact and utility tractors. It’s designed for diesel models from the 20D, 20E, 20F, 30E, 30H, 40, 40E, 50, 231, 240, 250, 255, and 298 series, as well as the 1674638M92 OEM part number.

Fitment & Compatibility

Before buying, verify your tractor’s model number (e.g., MF 255, MF 240) and the existing gauge’s mounting hole diameter—this unit uses a standard 3-3/8” (85mm) cutout. Check that your tractor has a mechanical (cable-driven) tachometer drive, not an electronic/sensor type. The gauge connects via a flexible cable to the engine’s tachometer drive port (usually on the injection pump or timing gear cover). Measure the cable length needed; this gauge does not include a cable. Confirm the OEM part number matches 1674638M92 or cross-reference your old gauge’s markings. Not compatible with models using a digital or magnetic pickup tach.

Key Things to Buy

• Quality concerns: With a 3.9 rating and 8 reviews, this is a budget aftermarket unit. Expect basic construction—may not match OEM fit/finish exactly.
• Installation difficulty: Moderate. You’ll need to route and connect the drive cable, then secure the gauge in the dash. May require removing the instrument panel.
• Common gotchas: The gauge face may be slightly different from original (white vs black, font style). The drive cable must be lubricated and properly seated to avoid erratic readings. No wiring required.
• Cable not included: You must buy a tachometer drive cable separately if yours is damaged or missing.

Should You Buy It

If you need a functional, affordable replacement for a worn-out mechanical tach on a Massey Ferguson compact tractor (especially 250, 255, 240, or 231 series) and don’t mind a slightly different appearance, this gauge works. Skip it if you want an exact OEM look or have an electronic tach system.