RD Johnson gear case drain plug stripped

[outbdnut2]

I’ve got an 35 HP RD that has stripped threads for the gear oil drain plug. The plug is fine, but threads are stripped in the housing. Has anyone else run into this? Is there a heilcoil that works? or can I drill it to the next size and re-tap it? or do I throw it away?

Dave

[david-bartlett]

If it is the drain hole in the skeg part of the housing, I would look for another skeg. Lots of them out there. I know people will say that the skeg and lower housing are machined as a unit and should be kept together, but I and many others have swapped parts with no ill effects.

[garry-in-michigan]

– And a few have ended up with noisy gears or leaky gear housings, but you will never know if you don’t try . . . 😆

[jerry-ahrens]

You can Heli Coil that, no problem, I’ve done it several times. I’ll have to look when I get to the shop, but I think I’ts 3/8 16 pitch thread. You can get the kit at an auto parts store. I’ll post the part # later unless somebody beats me to it. I like to use red Loc Tite to hold the insert in place.

[outboardnut]

I’m just thinking out loud here-but would it be possible to weld the stripped hole and drill and tap a new one in a different place?

[RICHARD A. WHITE]

quote outboardnut:

I’m just thinking out loud here-but would it be possible to weld the stripped hole and drill and tap a new one in a different place?

Quick answer is yes it can be welded and re-threaded, BUT, remember the axis of that thread is meant to be perpendicular to the spot face ensuring the washer will seal if you are off more than a degree or so, the seal may or may not work. I am sure they had jigs at the factory, for that very reason.

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[outbdnut2]

Thx for the recommendations. I didn’t know how mixing upper and lower housings from different motors would work. I have a lower housing from one with a damaged cavitation plate – I’ll see how that one lines up. If that doesn’t work, I’ll look into the helicoil. I don’t have access to aluminum welding equipment, so welding up the hole is not in the cards for me unless I find a welding shop.
Dave

[RICHARD A. WHITE]

quote Richard A. White:

quote outboardnut:

I’m just thinking out loud here-but would it be possible to weld the stripped hole and drill and tap a new one in a different place?

Quick answer is yes it can be welded and re-threaded, BUT, remember the axis of that thread is meant to be perpendicular to the spot face ensuring the washer will seal. If you are off more than a degree or so, the seal may or may not work. I am sure they had jigs at the factory, for that very reason.

http://www.richardsoutboardtools.com
classicomctools@gmail.com

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