Lower Housing Gears Will Not Engage

[Bourbon1792]

1970 Mercruiser 120 HP with inboard stern drive (SN2795699). I removed the lower gear housing to replace the impeller. As I prepared to assemble the gear housing to the driveshaft housing, noticed when rotating the propeller shaft counterclockwise, the drive shaft does not turn. I turned the shift shaft counterclockwise as far as it will go, while at the same time, turning the propeller shaft counterclockwise... I can feel the gear wanting to engage, but the won't. Any ideas?

Thanks, Tom

 

[achris]

1970 Mercruiser 120 HP with inboard stern drive (SN2795699). I removed the lower gear housing to replace the impeller. As I prepared to assemble the gear housing to the driveshaft housing, noticed when rotating the propeller shaft counterclockwise,

The propeller would be going in reverse, yes...

the drive shaft does not turn. I turned the shift shaft counterclockwise as far as it will go,

To engage reverse, yes..

while at the same time, turning the propeller shaft counterclockwise... I can feel the gear wanting to engage, but the won't. Any ideas?

Thanks, Tom

Yes, one idea, just one. If you want to get the drive shaft to turn while turning the propeller shaft, you need to engage the opposite gear., not the same...

If you're turning the propeller shaft reverse (CCW) , then the gear housing needs to have forward gear engaged. And if you want the drive shaft to move while turning the propeller shaft forward (CW), you need reverse gear to be engaged. That's just how ramped dog clutches work.

Chris........

 

[Bourbon1792]

Thanks Chris. I will give it a try later today. Thomas

 

[racerone]

Did you remove gearcase with control box lever in forward or neutral ?------What are you expecting to feel on propshaft with the unit in reverse?------What are you expecting to feel on propshaft with lower unit in forward?