Lower unit swap?

Bearcamp

Petty Officer 1st Class
Joined
May 21, 2003
Messages
341
Will a lower unit from a 1965 15-18 hp fit on a 1970 20-25 hp? I know it looks the same,BUT?
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Lower unit swap?

They used that gearcase for a long time on 18s thru 25s. I expect it would fit fine. Later ones up to 28Hp had splined propshafts, but I think they'd even work. Johnson, Evinrude, and Gale (Sea Kings, Buccaneers, etc.).
 

Bearcamp

Petty Officer 1st Class
Joined
May 21, 2003
Messages
341
Re: Lower unit swap?

I've been lookin for a lower unit for my 1970 20 hp and there's one on ebay, auction number 451701072. He states it's 1963-1965 for 15-18 hp. It's the one I was wondering if it'll work.really all I need are the gears and clutch dog but new is arounf 300, WOW.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: Lower unit swap?

Hi Bearcamp,<br /> Yes, you should be able to make it work. If you attempt to use the earlier gears in the later housing, you may have some depth issues in regards to the pinion gear as I think they changed the thrust washer & bearing arrangement somewhere in there... But, the early unit should work as a whole.<br />- Scott
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Lower unit swap?

The new gear kit is a vast improvement over the old one. It converts easily, but almost none of the old guts go back in. It has a locking mechanism that helps keep the gears engaged. Before they wore the engaging cogs if the shifter was out of adjustment. The new system outlasts the old by at least 3 to 1.<br /><br />If you get that gearcase off ebay, it could have the same problem as your current one. If it hasn't had that gear upgrade, that's a major possibility. If it has, you might be able to swing a pretty good deal.
 
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