Hello, I am helping a friend fix up a 1976 boat with a Mercruiser 165 which has been and will be run in salt water. I have worked on a lot of cars ect... but am some what unexpired with marine repairs. I am in the middle of repairing the shift cable from the back of the engine into the out drive. I have successfully removed the old one which was the "new" style I believe which matches the replacement kit I bought. The head of the brass screw was facing aft, threading in from the stern to the bow. I started to chase the threads with I believe a 9/16 - 18 NF tap which seamed to match the brass screw of the cable. I found the threads in the housing to be corroded and fairly washed out. I only started to thread in the tap but it didn't seam to be starting well and didn't want to cross thread it or remove any aluminum ect. I cut the cable off the old cable at the screw which does thread in and feels like it tightens well.
My concern is the threads not holding the brass screw and leaking water, being run in saltwater. There was a bunch of old salt build up in the cavity where the end of the cable and aluminum "shifter block" is inside the case. I wonder if the leak came from the threads or the old cable which had a hole in the outer sleeve just before the rubber boot causing it to rust from the inside. Is there a proper way to route the cable to allow for some play so it doesn't rub on the outdrive housing to note when installing the new one? Also wonder about is there any seals on the shifter shaft that runs vertically down into the lower end. Noticed the two bushing above and below the exhaust port seam to have some play. currently covered in grease. Does just a coating of grease form a sufficient seal?
My thoughts are to use pipe dope or tape, or silicone rtv to seal the threads, or clean out the threads and use JB weld to build it back up and re tap it, or a heli-coil but worried about possible corrosion reaction between the coil and aluminum??? Also thought about jb welding the brass screw into the housing but not sure I want a permanent installation of the cable like that.
Thoughts and insights on how to make a proper repair would be much apricated. I can add some pictures if that would help.
Thank you
My concern is the threads not holding the brass screw and leaking water, being run in saltwater. There was a bunch of old salt build up in the cavity where the end of the cable and aluminum "shifter block" is inside the case. I wonder if the leak came from the threads or the old cable which had a hole in the outer sleeve just before the rubber boot causing it to rust from the inside. Is there a proper way to route the cable to allow for some play so it doesn't rub on the outdrive housing to note when installing the new one? Also wonder about is there any seals on the shifter shaft that runs vertically down into the lower end. Noticed the two bushing above and below the exhaust port seam to have some play. currently covered in grease. Does just a coating of grease form a sufficient seal?
My thoughts are to use pipe dope or tape, or silicone rtv to seal the threads, or clean out the threads and use JB weld to build it back up and re tap it, or a heli-coil but worried about possible corrosion reaction between the coil and aluminum??? Also thought about jb welding the brass screw into the housing but not sure I want a permanent installation of the cable like that.
Thoughts and insights on how to make a proper repair would be much apricated. I can add some pictures if that would help.
Thank you
