Direct Drive Output is STUCK!!

[mike7a10]

I am trying to remove the direct drive/reversing gear. I am having one hell of a time trying to get the direct drive coupling off of the shaft. The nut was a bear to remove but it is now off. But now I cannot get the direct drive coupling to budge.

I purchased (3) 3/8" x 3" fine thread bolts as the manual suggests and began tightening them with a socket to press off the coupling and got to a point where it actually stripped the threads in the direct drive coupling! Now I will most likely have to replace the direct drive coupling... I did run a tap through the threads but I am not sure if it saved it. I am not going to try to use the 3 bolts to press off the coupling again as I am sure it will totally ruin it if it isn't already there.

I then started using oversized screwdrivers to try and pry it off by tapping in the screwdrivers between the d.d. coupling and the oil seal. No luck.

Won't move, nada. I have sprayed it with JB penetrating oil and heated up the coupling and tapping on it, etc.. Again, nothing.

This thing is either rusted in place or there must be something wrong. I cannot image that it is so stuck that I probably ruined my direct drive coupling. Any advice? I mostly have the engine apart and was planning on taking it to be machined...

I did read in the MMI manual that Don states you can remove the reversing gear without removing the coupling and that is most likely what I am going to have to do. In the meantime, anyone have a suggestion on why I cannot get this coupling to budge?

As always thank you all in advance for any assistance!

(I appreciated all of the input under my original thread for this project under cooling system-Serious Oil/Water)

Mike
S/V Plan Sea

[msauntry]

Try again with the heat and let it get really hot. Can you get a three armed gear puller on it? One trick is to tighten the puller and then tap the shaft with a hammer. It may fly off with some force, so be prepared.

[Don Moyer]

Mike,

We're so sorry to hear of your output coupling struggle. The fact that the threads stripped on your coupling is not a good sign. About once every 5 years we run across a coupling that simply will not yield without the services of a well equipped machine shop - and since we haven't heard of one for quite some time, it appears that you might have the winning coupling during this five year period.

The only puller I know of that might work is the style that has two very hard plates with the center area machined concave sufficiently to go between the coupling and the rear engine housing. I don't know what this type of puller is called but your local machine shop will surely have one (if you describe it to them) which they might loan or rent to you. Unfortunately, these pullers require more space than exists on most boats which means that you'll have to remove the entire reversing gear and aft housing together. If this turns out to be your situation, you may as well take the entire assembly in to the machine shop and let them deal with it.

This appears to be one of those cases in which the only real support we can offer is to reassure you that you will definitely finally prevail, and (more importantly) when you do you'll be a far better person for the experience.

Don

[mike7a10]

PHOTOS & Thanks!

Thanks guys. I appreciate the support!

I went ahead and removed the reversing gear with the coupling on the shaft. I will try to get the gear puller you are describing. The engine is out of the boat and in my garage. I have her mostly broken apart. I am contemplating removing the crank and cam shafts & pistons and having the block and head machined. I am also likely going to have all of the major housing parts dipped. Heck...I'm this far into it and I may as well have it done right.

I'm not too sure I will be a better man for the experience but I have a feeling that this is an exercise in the attainment of patience!!

[rigspelt]

Great photos - thanks. Handy for future reference.

Picked a colour yet?