Lonestar66
Cadet
- Joined
- Jan 13, 2019
- Messages
- 14
I recently bought a 1967 Mercury 500 50hp long shaft outboard for my boat, after purchasing it i realized it had a 11 Spline Prop shaft and only one company produces it still (propco).
I'd like to swap it to the newer style 13 spline prop shaft lower unit so i have a larger variety of props. I've researched the parts compatibility between a 1967 and a mid 70's lower unit. The shift shaft is the same length and spline count (6 spline) but the reverse lock/cam/guides are different. (67 Part #'s: 52918, 52919, 52920) (70's Part #'s: 78036, 43308T1, 52917)
The Drive shaft is the same length from the top of the water pump housing to the end of the splines. same spline count as well (11 spline). but the mid 70's drive shaft has no O-Ring Grove on the shaft and appears to be a pin at the end of the shaft (67 Driveshaft part #: 46394) (70's Driveshaft part #: 57359A1) the driveshafts are not interchangeable with each other cause of different bearings and pinion gear splines.
I believe I can swap the 13 spline prop shaft into the 67 Housing but some modifications would need to be made. if i were to use the existing bearing carrier i would need to machine the bearing carrier roller bearing pocket from 1 inch to 1.125" to accept the larger bearing. other then that the rest of the parts swap easily.
Anyone have info on either of these swaps or suggestions?
Thanks
I'd like to swap it to the newer style 13 spline prop shaft lower unit so i have a larger variety of props. I've researched the parts compatibility between a 1967 and a mid 70's lower unit. The shift shaft is the same length and spline count (6 spline) but the reverse lock/cam/guides are different. (67 Part #'s: 52918, 52919, 52920) (70's Part #'s: 78036, 43308T1, 52917)
The Drive shaft is the same length from the top of the water pump housing to the end of the splines. same spline count as well (11 spline). but the mid 70's drive shaft has no O-Ring Grove on the shaft and appears to be a pin at the end of the shaft (67 Driveshaft part #: 46394) (70's Driveshaft part #: 57359A1) the driveshafts are not interchangeable with each other cause of different bearings and pinion gear splines.
I believe I can swap the 13 spline prop shaft into the 67 Housing but some modifications would need to be made. if i were to use the existing bearing carrier i would need to machine the bearing carrier roller bearing pocket from 1 inch to 1.125" to accept the larger bearing. other then that the rest of the parts swap easily.
Anyone have info on either of these swaps or suggestions?
Thanks