Transmission Drive Plates
How to Determine the Correct Marine Transmission Drive Plate Size for Your Boat
- Measure the outside diameter of the drive plate.
- Measure the diameter of the retaining bolt circle.
- Measure and count the number of bolt holes.
- Measure the outside diameter of the transmission shaft.
- Count the splines on the shaft-twice!
- Measure the thickness of the old drive plate, including the center hub, but excluding any raised areas or rivet heads on the flywheel side of the plate. If the new disc is thicker than the old one (A), the transmission may not bolt properly. If the new disc is thinner than the old one (B), the transmission shaft may not reach the full depth of splines.
- Check for the original part number on the old plate. The number will help your parts person get the right spring tension, or in the case of an elastomer style, the old number will help you get the right durometer rating.
- Finally, check for a directional arrow.