Rebuilding lower unit of a 10 Hp Johnson

[CritterBob]

Got a qd 20 10 hp Johnson I am trying to rebuid. Bought a Clymer book at the local boat repair shop and I am somewhat disappointed with the book. I am trying to rebuild the lower unit and the book is hard for me to follow.
Long story short I found the pinion gear was missing some teeth. What causes the part to fail? Any idea what it will cost to replace?

 

[R.Johnson]

Re: Rebuilding lower unit of a 10 Hp Johnson

Take a look at the lower drive shaft bushing, that is the point where the drive shaft, and pinion join. See if it, and the lower drive shaft are badly worn. If it is, the gearcase is sprung. A badly worn shaft, and bushing will put undo strain on the outer tooth of the gear. Don't put new parts in the gearcase if it show's these signs.

 

[bbenkaz]

Re: Rebuilding lower unit of a 10 Hp Johnson

If you need a lower unit for that motor I can get you in touch with the guy I got my parts from, he is very reasonably priced and extremly nice. Send me an email if you want

 

[CritterBob]

Re: Rebuilding lower unit of a 10 Hp Johnson

If you need a lower unit for that motor I can get you in touch with the guy I got my parts from, he is very reasonably priced and extremly nice. Send me an email if you want

Looks like I am in the market for a new lower unit.

 

[samo_ott]

Re: Rebuilding lower unit of a 10 Hp Johnson

I have 2 QD19's that did the exact same thing. Both had the lower bushing and drive shaft worn so much that the pinon teeth and forward gear teeth shredded... You need a new lower case and then rebuild.