Reply To: Johnson CD-14 Frozen Pinion Gear-Shock Absorber

[Don]

James Tapscott wrote:

Success!! Screwdrivers didn’t work, but punch got it out. Not as rusty as I thought. I guess running it dry of oil overheated it and the heat caused everything to seize up. Will soak all parts for another day and start cleaning up and order gaskets etc. Drive shaft and shift rod bearings look ok. I’d rather not replace them unless one of you experts insists otherwise. Once this one is back running I have similar vintage Johnson 10, Evinrude 15, E 18, E 3 and an old old Johnson 1.5, all in need of various repairs. Should keep me busy for a few years!
Thanks again.

Jim

I know we have mentioned it, but worth repeating…Check the length of the lower driveshaft/shock absorber before reassembly. Oftentimes the shock will “expand/break” pushing the two parts of the lower driveshaft apart extending its length….The result is that the top of the lower driveshaft will rub/bind on the upper bushing/seal assembly, this will cause the driveshaft to bind. Look on the bottom of the upper seal/bushing housing, rubbing will be evident if there is a problem
On to your other issue, whether or not to reseal this gearcase completely. There are definitely two schools of thought on this. One opinion is that the unit should be completely resealed before reassembly to avoid water intrusion/damage after assembly. You can’t really make the comparison between a slightly leaky gearcase and an old car engine that leaks oil slightly. In most cases, you would not bother to reseal an old car engine, not worth the money. In addition, the engine’s oil level can be monitored easily, and oil added as necessary….
The outboard gearcase is another story. These units really have pretty much a zero tolerance for lube leakage, why is that you ask….First of all, as the oil leaks out, raw water is likely to leak back into the gearcase which will destroy it eventually. Furthermore, gearcase oil level is not that easy to check…Even if the gearcase appears to be full of “lube”, all the water is probably at the bottom of the gearcase. Trying to “top off” the outboard gearcase is difficult as well…Probably easier to just drain and refill it.
The other argument is “why go through the trouble of replacing seals and orings that appear to be OK”. I can understand this argument if you know for a fact that the gearcase was recently resealed. The part you mentioned, the shift rod oring, is a common source of leakage on these gearcases, and the oring on the prop shaft bushing/seal housing should be discarded during every repair job.
It is tough for me to make a recommendation here. I get frustrated when resealing these gearcases is described as relatively simple, this is a tricky procedure that must be performed perfectly….Some special tools are required, and the parts are easy to damage while trying to remove/install seals and bushings. The one tool that is absolutely necessary is some sort of pressure tester to check your work once the gearcase is reassembled. Again, there is pretty much zero tolerance for any leakage. Even the best reseal job is useless if any of the castings are porous/cracked/distorted, there is no way to check this without a pressure test.
Ideally, it would be great if you could get together with a member that has experience with these gearcases…Again, removing the seals, shift rod bushing is tricky, and it is easy to damage the small aluminum pieces. If meeting up with a member is not an option, then I don’t recommend attacking the seals/shift rod oring. I would replace the large oring, and the spaghetti seal between the gearcase halves, along with the gasket under the upper bushing/seal assembly. Prior to reassembly, I would pump the shift rod bushing cavity/hole full of marine grease to help seal up any issues there, and perhaps loosen up the oring….
Once the unit is reassembled, gear lube should be changed frequently to ensure there are no major oil leaks….D