What are my Lower unit options??? 94 1/2 120hp Force

[tater76]

Hey again folks, so just got done building a 94 1/2 120 hp Force. The crank was bad and I ordered one off of eBay. Got it all put back together only to find that my 15 spline crank will not accept my 13 spline driveshaft... DOH!! So... my options are limited due to money (can't just buy another lower unit) so I am wondering if a 15 spline shaft can be installed in the existing lower??? are there any differences in shaft diameter, length, etc..? and how difficult would a shaft R&R be on this year of unit?

 

[Frank Acampora]

Re: What are my Lower unit options??? 94 1/2 120hp Force

Ah-Ha! You didn't check what year engine the crank came from. Late Forces with Mercury lower units used different crank splines. However--and I am a little fuzzy here so bear with me-- Your lower unit has the two piece drive shaft. It MAY--MAY be possible to swap in a Mercury driveshaft if they are the same length, because as I remember, the coupler was the same on all years. BUT, I don't know if the Mercury engine used the same lengtth shaft because they had a different match plate than earlier Force engines.

 

[tater76]

Re: What are my Lower unit options??? 94 1/2 120hp Force

Well... the crank was from a 92, and I had no idea the splines changed during the Merc years. My lower is a one peice shaft. I guess I will be looking for a 13 spline crank this sucks. Thanks for the info, and if anyone has a 120 crank with 13 splines let me know.

 

[Frank Acampora]

Re: What are my Lower unit options??? 94 1/2 120hp Force

Hmmmm---Where did I see a 13 spline crank? I know I saw one and was thinking How merc changed the splines. Let me hunt around the garage for a couple of days and I will get back to you If I find one.

Nope-- you are out of luck. I think that was the crank that was so badly rusted that I brought it to the scrapyard along with other steel.