My primary drain hole is stripped.75 Ironhead.Any solutions would be appreciated.

 

Helicoil ?

 

Not sure what size it is now...but I am sure its a NPT thread which is a pipe thread. You can probably go to the next sice bigger and retap it with a bigger NPT size....or if you had to maybe a slightly larger metric thread. I wouldnt go any bigger than you had to, just enough to get go sealing threads again. If you end up retapping it ...dont thread the tap in too far. The deeper the tap goes, the deeper the plug has to screw in to seal....if that makes sense...as the plugs are tapered... Just some thoughts...

 

I would try re-tapping it 1 size bigger and use some teflon tape or white hydraulic seal loctite on the drain plug. Just make certain you flush the hole after tapping to get all metal threads out. Best of luck. KB.

 

I think I would remove the cover to repair the thread.At that point I would retap the hole with the next size NPT tap or use a straight tap and use a drain plug and washer if the case is flat on the bottom.
It would be better to have a machinist do this.The cover should be bolted/clamped to an angle plate on a mill.This way the thread will be straight.

 

It's not the space shuttle. Worst case scenario is you have someone tig weld it shut and shoot a new hole and NPT tap it. No clamping on a mill needed here. Take the cover off because you have parts behind there and you want to be professional - right?

 

So doing the work on a mill is not professional?
Why weld the hole?
So you would drill a new hole with a hand drill?
I've been a machinist for 29 years and know how to fix **** like this.

 

Drill the hole by hand , it will follow the existing hole - however straight it may or may not be ! This is not ROCKET SCIENCE as some would lead you to believe ! Do remove the cover , that way you get no metal shavings inside . And take it easy cranking that thing next time , steel plug into aluminum cover ya know !

Good Luck , Dan

 

The point is it's total overkill, and how much time are you going to spend mounting a primary on a mill for a rough hole. For goodness sake, don't take it so personally.

 

They make self tapping replacement oil plugs. The problem with these in aluminum is they can ball up while tapping.

The perfect fix is to remove the pan, tig weld up the hole and redrill and tap it. While you do this you can add extra metal to keep this from happening again.

If you drill it oversize make sure you flush the shavings out.

Good luck