1978 Johnson 140 hp Lower Unit

[AguaSki]

I have been chasing a combination problem of lower unit rattling and shifting problems for several weeks now. After unsuccessfully trying every possible adjustment to correct the situation, I finally cracked open the lower unit to see what was going on. Below is a pic of the pinion gear and the forward gear. As you can tell these gears are shot. There was also a lot of super fine metal shavings in the oil. I am afraid that the metal dust has made its way into all the bearings. After pricing several of the pieces that need replacement, I have decided on picking up a used replacement lower unit. I just found a good used lower unit, and I should have it in the next 10 days. I have had this boat and motor for 4 seasons, and I have always been anal about changing the lube each season. I take care of most any asset I own, so I like to think that this mechanical failure was not due to a lack of routine maintenance. When I drained the oil I did not see any signs of water intrusion. I am curious to hear if anyone has any ideas on what might have caused this damage. Is it possible that the damage was already well underway when I acquired the boat 4 years ago? If I can figure out what caused this, I may be able to prevent this from happening on my new/used lower unit.

Also, since I have a new/used lower unit coming, I would like to offset some of my expenses by parting this lower unit. I will probably list anything that is salvageable on Ebay. I pride myself on my 100% feedback rating on Ebay, so I want to be careful that I don't sell parts that should not be reused again. What parts from the lower unit still carry salvage value and are likely to have not experienced damage? Should I list the parts individually or as one "Basket Case"?

Please share thoughts.

 

[k4ubr]

Re: 1978 Johnson 140 hp Lower Unit

the problem could come from many things age is a big factor. you can hit your prop on something and brake a tooth. (that is what happend to the gear it drop a tooth witch gear oh knows) but more than once this has happend.