71 20hp Johnson drive shaft seal replacement

435vette

Recruit
Joined
Aug 2, 2009
Messages
5
My son's 71 20 hp Johnson (20R71S) weeps some oil after shut down from the small holes in the LU. I guess I need to replace the drive shaft (garlock) seal and shift rod (o-ring) seal? Might as well replace the impellor while I'm there? Any help or tips in performing these task would be appreciated, such as drive shaft seal & impellor removal/install, etc. Thanks guys!
 

Feathercraf1

Cadet
Joined
Aug 9, 2009
Messages
16
Re: 71 20hp Johnson drive shaft seal replacement

Check how much water is in your gearcase by pushing some grease into your lowest oil plug as you open the top one.

I would suggest replacing the long gearcase parting surface seal (It's weird)
and the propshaft garlock, Usually, all these garlocks are available at your bearing supply house at lower cost than OMC/Bombardieyay.
 

435vette

Recruit
Joined
Aug 2, 2009
Messages
5
Re: 71 20hp Johnson drive shaft seal replacement

Thanks for the post/help. I think the gear case & gear case head seals are holding as no water was noted in LU oil. With some effort and patience, we replaced the 38 yr old drive shaft garlock seal, which was allowing oil to leak out and was covered in oil.
We were unsuccesfull in the shift rod o-ring install as it appears to be retained between a brass bushing and phenolic washer. Is this installed from the bottom by splitting the gear case? Impeller was easy, Getting close, Thanks guys!
 
Top