1987 johnson, clutch dog and foward/reverse need replacing? 40hp

jdlanders

Cadet
Joined
May 13, 2008
Messages
20
i need an opinion concerning my engine's lower unit which is in the shop. Last weekend I notice some lower unit oil leaking from a water drain whole on the lower unit. I removed the lower unit and found the seal around the shift rod needed to be replaced. I took the lower unit to a shop and was going to have them replace all seals for me, been too busy to at work to get it done myself.

Shop calls and says I need new foward and reverse gears, as well as a new clutch. The engine has been slipping going into reverse some, but has been a smooth as butter going into foward, no slipping once in gear.

I went and looked at the parts at the shop, reverse gear is slightly rounded where the clutch connects to the gear. Forward is rather square, but has some lines on the top part of the notch that catches the clutch (possibly been put in gear while the engine was rotating to fast?).

Do I necessarily need to replace these parts? Is it a ticking time bomb? could I possibly get another year out of it?

Any advise is appreciated.
 

dkonrai

Senior Chief Petty Officer
Joined
May 9, 2009
Messages
719
Re: 1987 johnson, clutch dog and foward/reverse need replacing? 40hp

my parts guy had explained lower unit gears as such:
"gears are made in batches. the metal in the batch will be equal in strenth and temper. when you change only one gear there is a compatability issue, as there is no gaurentee that the temper or metal make up will be the same"

im sure others will chime in on this, however when this was explained to me many years ago i believed him, makes sense really,
 

jdlanders

Cadet
Joined
May 13, 2008
Messages
20
Re: 1987 johnson, clutch dog and foward/reverse need replacing? 40hp

I agree, if I am going to replace them, I will replace them all. What I want to know is this: does one need to replace the clutch and forward/reverse at the first signs of it slipping when going in gear? Is any amount of rounding on these parts acceptable, or should they always be perfectly square?

Thanks for the reply.

JL
 

dkonrai

Senior Chief Petty Officer
Joined
May 9, 2009
Messages
719
Re: 1987 johnson, clutch dog and foward/reverse need replacing? 40hp

if it was my motor, and i planned on keeping the motor (not to resell) i would replace the gears and clutch dog. the worst case scenario running at wot, and loosing something and possibly damaging the housing. jmho
dino
 
Top