End cap removal

[wimico]

I have seen reference on a couple of posts about a tool to remove the lower crank end cap from a Merc powerhead. Can someone tell me basically how this tool works? I have a buddy that owns a machine shop that I'm sure could fabricate a tool if we know the principle of how the thing works.
By the way, there are six holes in the end cap. Three obviously for the bolts and three more that are about 3/16" but are not threaded. I assume I could thread these and use a suitable puller.

 

[emckelvy]

Re: End cap removal

By the way, there are six holes in the end cap. Three obviously for the bolts and three more that are about 3/16" but are not threaded. I assume I could thread these and use a suitable puller.

Yup, that'd be the best way to pull, using a puller that can bolt up to the three holes. The end cap is merely a snug fit into the machined I.D. of the block, and with enough persuasion it'll come right out. Using a proper puller you shouldn't even need to loosen the bottom (2) crankcase-half bolts.

I'm assuming you're looking to change out the lower seals; be sure to note their orientation and position before you drive out the old ones. Also ensure the new ones are pressed back into the exact same place as the old.

If you find the crankshaft seal surface is rusty or worn, Merc sells a purpose-built "speedi sleeve" that you can press on the end of the crank to give the seals a new surface to bear against. Same idea as a seal-saver for an automotive harmonic balancer.

Lube up the new seals with a thin coating of engine oil, assy lube, Lubriplate, etc.

Renew the bearing cap O-ring as well, and when you reinstall use caution to drive it down evenly. Note that the cap will only bolt up properly in one position as the spacing of the bolts holes is not even.

I like to use a sparing coating of Permatex #3 Aviation-Type gasket dressing on the bearing cap O-ring and on the flange as well, this helps seal salt and other debris out of the cap-to-block interface. Just be sure not to get any sealer on any oil drainage holes which may be present in the cap.

It's very tempting to pry upon the 'ears' of the cap but you've got the right idea to use a puller. It's also very easy to break the ears using improper disassembly techniques!

HTH & Merry Christmas........ed

 

[wimico]

Re: End cap removal

Thanks for your input. I'm going to tap those 3/16 holes and use a harmonic balancer puller. It's cold and snowing right now (in Ga) so it will be a few days before I will try it since the motor is outside in my carport. I will post the results when I get done.
Thanks again.

 

[j_martin]

Re: End cap removal

Thanks for your input. I'm going to tap those 3/16 holes and use a harmonic balancer puller. It's cold and snowing right now (in Ga) so it will be a few days before I will try it since the motor is outside in my carport. I will post the results when I get done.
Thanks again.

It's aluminum, with a high rate of thermal expansion. Cold is your enemy.

 

[wimico]

Re: End cap removal

Success!!
I tapped those three holes at 1/4" 20 and used a harmonic balancer puller. She came out slick as a whistle.
Bearing came out with the cap so I hope that is not a problem.

 

[emckelvy]

Re: End cap removal

You'll have to remove the bearing in order to replace the crankshaft seals. Most likely the removal method will damage the bearing. You didn't say what HP/year your motor was, but I'll assume it's one that carries a '6206' or simply '206' ball bearing which is readily available at most auto parts stores or bearing specialty shops.

You may be able to get it out without damaging it by rapidly heating the outside of the end cap around the bearing area, the bearing just may fall out on its own. But it'd be better to replace anyway since they're so inexpensive.

Your machine shop buddy could make you up a fixture that you could insert into the i.d. of the bearing in order to press it out from the other end. This of course will damage the bearing but at least it'll be out!

Be sure to press only on the outer race of the bearing when reinstalling, to avoid damage. Heating up the end cap a bit will help with fitment, just don't get it too hot or you'll damage the newly-installed seals.

HTH.......ed

 

[wimico]

Re: End cap removal

I found the bearing at a local auto parts store for eight bucks and reinstalled the end cap yesterday. A fine film of high quality white grease on the crankshaft and end cap helped get her back in there. I also used the Permatex #3 on the lower end of the cap and around the O ring as suggested. A very slow and methodical tightening of the retaining bolts in the cap pulled the cap back in and all seems fine. Now I can proceed with the reassembly of the rest of the motor.

Thanks for all the suggestions and help. This forum is great!!!!