Shift rod becomes stiff due to swollen/corroded O rings at gear case!

[muncedog]

From googling I think is relatively common issue but not every 2 years!

Any thoughts on what causes this or how to avoid/prolong the life?

My thoughts are:
O-ring having a chemical reaction with some applied product rather than just salt water? E.g. gear oil volatile vapours/fumes as this sits above the oil level - always smells eggy to me that stuff! That said might sit in oil when motor trimmed up on driveway.

reaction with the recommended grease?

Galvanic corrosion between the stainless rod and the aluminium housing?

Plastic spacer cone (first photo) trapping dirt/moisture not allowing it to breath and stay dry at the seal?

Rust coming down the shift rod 'shaft/pipe' enclosure from the steering arm (not sure how its supposed to be sealed off from this)

Last thought is the location of the shift rod connection at the motor, its at the bottom of the cowling, almost like a drain point - perhaps if any gas / aggressive cleaner was spilt it would drain down the shaft and end up resting on the seals?

I also wonder if the white corrosion isn't salt but dried old grease?

Any thoughts or experience would be greatly appreciated, otherwise this will be done again in 2 years!

Thanks

 

[Grub54891]

Salt water is one mean animal. Could you apply a thick grease to the shaft? Are you installing a new o ring, old ones get hard and stiff over time.

 

[oldboat1]

Go out to the garage with a can of Coke in hand, and see if cola on a shop rag will clean it up (trial and error exercise). I use marine grease for protection, again applied with a shop rag.

 

[racerone]

It does not happen on fresh water motors.------So the assumptions about the nasty oil smell are all wrong.------It is the salt water environment that is the issue.-----Possibly plastic bushings elsewhere on the motor jamming as well.

 

[Joe Reeves]

I've been following this thread thru. Strange I've never encountered that swollen "O" Ring problem... and salt water is aplenty in the Delaware Bay area and later in life, the Gulf of Mexico. Are those "O" Rings factory replacement items?

 

[heypawpaw]

Had issue with 1996 Evenrude 88 SPL a couple years ago. It started to not go in reverse so I adjusted cables at motor and all ok for a while then happened again and if I adjusted cable enough for reverse to work forward wouldn't. Was told by a friend to check shift rod o ring. Dropped the lower unit and galvanic corrosion was built up on shift rod above and below the o ring making it very hard to shift. Removed old o ring and used fine sandpaper then steel wool to clean up shift rod then replaced o ring and put a light film of grease on shift rod. problem solved. Gotta love that Louisiana salt and brackish water.