Keep your speedometer reading true with the ATP Speedometer Drive Gear YA-18 (also written YA18). This silver 22-tooth drive gear installs in GM automatic transmissions — TH-200, TH-250, TH400 and TH700-R4 — where it meshes with the driven gear to turn the speedometer cable and set the correct calibration. It fits a broad range of GM applications, including the 1975-1980 Chevrolet Monte Carlo, 1975-1980 Chevrolet El Camino, 1975-1981 Buick Regal, 1978-1980 Oldsmobile Cutlass Calais and 1975-1984 Cadillac Fleetwood — see the Buyer's Guide tab for the full 236-application list.
If an inaccurate or non-working speedometer traces back to a worn or wrong-tooth-count drive gear, this replaces it. Confirm the tooth count required for your application before ordering.
Interchange: 41387 · 74084 · 3987922
This part cross-references / interchanges with the following part numbers:
How many teeth does this speedometer gear have?
The ATP YA-18 is a 22-tooth drive gear. Tooth count affects speedometer calibration, so confirm 22 teeth is correct for your application before ordering.
Which transmissions does the YA-18 fit?
It is listed for GM TH-200, TH-250, TH400 and TH700-R4 automatic transmissions. Check the Buyer's Guide tab to confirm your exact vehicle and transmission.
What does a speedometer drive gear do?
It rotates with the transmission output and meshes with the driven gear to turn the speedometer cable, so the tooth count helps set the speed reading.
Can a bad drive gear cause an inaccurate speedometer?
Yes. A worn gear or the wrong tooth count can make the speedometer read incorrectly or not work. If the drive gear is the cause, this part replaces it.
What color is this gear and what part numbers does it replace?
It is silver. It interchanges with 41387, 74084 and 3987922.
WARNING: These products can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
