Heat to Free Seized Shift Shaft Coupler?

[minuteman62-64]

1982 Mariner, 30 HP. Upper and lower shift shafts are joined with a threaded coupling that is seized (preventing me from dropping the lower unit). I'm working with penetrating substances in an effort to free it up. I'm thinking heat will be the next step, if that is un-successful.

I've read conflicting reports of using heat -from ".... freed it right up" to "....froze it so it will never come off".

Some questions:

Heat, yes or no?

Heat the coupling nut or the threaded shift shaft?

How hot for best results?

One reference I read suggested heating while applying beeswax - the idea being that the beeswax will thin and migrate down and help free up the fastening. Anybody used that?

If heat is a no-go I'll be pulling the power head to unfasten the upper shift shaft where it connects to the shifting mechanism.

 

[5150abf]

Re: Heat to Free Seized Shift Shaft Coupler?

AS long as you aren't melting anything heat is fine and normally does the job.

How much heat depends on how stuck the bolt is and you woudl want to hit the nut on the outside, together with the penatrating oil that should get it.

 

[Home Cookin']

Re: Heat to Free Seized Shift Shaft Coupler?

go slow slow slow

 

[minuteman62-64]

Re: Heat to Free Seized Shift Shaft Coupler?

Saved, by the $7.99 Harbor Freight Micro-Torch (and a $4.99 container of butane). Smeared some beeswax (from old toilet bowl rings) on the threads above the coupling and used my newly purchased Micro-Torch to carefully heat the coupling nut. Applied some heat and tried to turn. Repeated 4 times, and, on the 4'th try - success - I had rotation.

To avoid future problems, what should I put on the shift shaft threads? Grease? Non-hardening Permatex? Anti-seize?