Stripped bottom LU oil drain plug ...

[pecheux]

Good day,

Yep I screwed up alright ... Local Merc dealer (parts dept) recommended using Allen-key type drain plugs for tighter fit ... It worked ... lol ... I over-tightened and stripped the LU tread on my 1997 Force 15 hp OB. My fault.

Can that be fixed ? I would like to know what my options are prior to heading for the repair shop ??

Thank you

 

[wickware]

Re: Stripped bottom LU oil drain plug ...

Why not use a self taping screw the next size up from the stripped hole that will cut it's own new set of threads? There are some plugs on the market for cars that are stripped. Such as on the boat's motor: If the stripped plug was a 1/4" X 20 NC, go to the next standard size "self taping screw 5/16 X ?. The flute/cutter in the new self tapping screw will usually hold the shavings from cutting new threads. OR! Drain the shavings.

Oops! I forgot that you will be working in a recessed area that will affect the new gasket and room for the new screw's head. BUT! I still feel this can work and there is possibly a kit already on the market or make your own.

Good Luck,
Joe

 

[Jack Daniels]

Re: Stripped bottom LU oil drain plug ...

not sure what to do but if it was me, i might take the internals out and drill out the threads and retap. Shoot, i might just take the internals out and take it to a machine shop and have it filled, redrilled, and tapped to the original size. I would hate to do a shotty repair and always have to deal with water in the lower unit. Seems like a lot of work, but at least you would know your not getting water intrusion and that you have a good repair.

 

[pecheux]

Re: Stripped bottom LU oil drain plug ...

not sure what to do but if it was me, i might take the internals out and drill out the threads and retap. Shoot, i might just take the internals out and take it to a machine shop and have it filled, redrilled, and tapped to the original size. I would hate to do a shotty repair and always have to deal with water in the lower unit. Seems like a lot of work, but at least you would know your not getting water intrusion and that you have a good repair.

The tread inside is already very thin and already had some of it missing which did let a bit of water in the LU which explains the overtightening. ... I dont see enough metal to enlarge by tapping bigger since there is already some metal missing.

Tx

 

[steelespike]

Re: Stripped bottom LU oil drain plug ...

Getting down and dirty cob job repair.Try to find a little boiler plug
resembles a boat drain plug. in miniature.Most have a little lever with a screw
substitute it for a little screw.Might stick out too far, too much drag.
Might have to drill a little; load up the drill with grease to catch the shavings.Be careful as the drill might grab pulling itself in.Run it a little and check for water infiltration.

 

[pecheux]

Re: Stripped bottom LU oil drain plug ...

Shoot, i might just take the internals out and take it to a machine shop and have it filled, redrilled, and tapped to the original size.

Explained the problem to an old friend who's an ex Mercury dealer and mecanic (retired) and that's what he recommended ... the whole thing has to come appart ... now how expensive is that going to be is another story since I dont know how to take this thing appart myself ... LOL Personaly I wish I could just find a complete rebuilt unit ... been searching the net without success.

tx

 

[pecheux]

Re: Stripped bottom LU oil drain plug ...

Why not use a self taping screw the next size up from the stripped hole that will cut it's own new set of threads? There are some plugs on the market for cars that are stripped. Such as on the boat's motor: If the stripped plug was a 1/4" X 20 NC, go to the next standard size "self taping screw 5/16 X ?. The flute/cutter in the new self tapping screw will usually hold the shavings from cutting new threads. OR! Drain the shavings.

Oops! I forgot that you will be working in a recessed area that will affect the new gasket and room for the new screw's head. BUT! I still feel this can work and there is possibly a kit already on the market or make your own.

Good Luck,
Joe

I went to my local Merc dealer shop today in order to find a larger plug or self tapping screw. Parts Mgr tells me all I need is a Helicoil to fix the problem. So he send me to their service dept and they confirm they do this type or repair year round ... they have my OB and the problem should be fixed within days. Cost of Helicoil $ 25. + installation + new oil. I am disapointed my ex Merc dealer/mech friend never mentioned it could be fixed so simply.