Help! Stripped drain plug!

I was changing the oil in my Kubota ZTR today and upon removing the drain plug it felt as though it was cross threaded.

Sure enough it was. And I am the only human that has touched that machine in 7 years...so...I guess it was me.

So. I get my retap set out and it retaps just fine, clean up the plug as well.

Screw it in and just as it is getting to the right spider-sense torque, you guessed it, it spun.

So, it is M12x1.25. Should I drill and tap M14x1.25 which is what my Toyota truck uses? What size drill would you use for that?

Should I buy one of these $100 kits?

https://www.amazon.com/dp/B003SESW78/ref=aag_m_pw_dp?ie=UTF8&m=A2J41G0RQ2IUXB

Or this helicoil?

https://www.amazon.com/Heli-Coil-554312-M12X1-25-Metric-Kit/dp/B000CMHVLC#customerReviews

Pulling the pan would be difficult. It is deep within the frame with structural members on each end so that would be a last resort.

Any ideas welcomed.

 

There was a thread swomewhere on FChat a few weeks ago where an owner had a similar problem and resolved it by tapping a new thread from the inside out. Perhaps pulling your pan might not be as difficult as first imagined when taking a fresh look or going to a Kubota forum to determine if there might be a secret trick to quickly removing the pan. Good luck to you.

 

A helicoil type solution is the best option and certainly more than sufficient for that purpose.

That looks like it would work. But its expensive for what it is...

I wouldn't buy that helicoil set just because the photo clearly shows a 12x1.25 tap - which is wrong. You need the helicoil tap which is bigger than 12x1.25 (and you said you already have a 12x1.25 anyway).

This kit is less than $20 and has all the components you need - 15Pcs/25Pcs Helicoil Restoring Thread Repair Wire Insert Kit Set With Hard Case | eBay

I've used this brand to restore threads in cast iron housings and they work perfectly.

 

I would not buy the first kit only because it is really over-priced. The labeling of the tap is fine. They label those helicoil taps for the size of the helicoil, not the size of the hole. It is just easier to ID that way. Keep it with the kits and you will not make a mistake.

I have the first and the second set of helicoil repair kits. The one from Australia will take 3 weeks to get to the US. Only buy that if you can wait that long.

 

Tapping drill is 12.8 for the M14x 1.25. If it is an alloy casing then back the cutting edge of the drill off a little to stop it digging in.
Best to price up the tap set as this is not a popular size.

 

OK - thanks. I've not seen them like that.

I get ebay Australia when I search - but those kits come direct from HK not Australia so would be at your door inside a week.

 

You can get a helicoil at a local auto parts store.

 

Heli-coils are also know as STI taps and as Mitch said, it's labeled as the final thread tap.

A metric size that large may not be available locally.

Wire Thread Inserts | Screw Thread Inserts | Stanley Engineered Fastening

 

Thank you gentlemen!

 

On the human level, the sad machice monopolizing my lift for the next week or so....🙂
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Are you also starting to suspect it stripped itself?


- via iPhone

 

For that particular situation, Time-serts are a much better way to go. But, they are a bit more tedious to install. If you take the effort to do it, it should be the last time you ever have to mess with it, though. Just make sure you have enough material in the casting around the hole to support it.

Time-Sert ? Time-Sert +Thread Repair System+ ? Kits and Inserts Official Site

They have a specific solution for oil pan plugs as well ---

Oil Pan Repair Kits ? Time-Sert

 

Think about fitting a 328 engine to it, would sound mighty

 

^^^This, in spades! Timesert> Helicoil every day of the week. If you want to fix it right, invest in a Timsert kit and glue that sucker in place with red Loctite. Properly installed, you'll never regret the extra effort of installing a Timesert.

Best of luck with the repair.

 

FWIW, on the 355 motor, Ferrari uses plenty of Heli Coils (or non branded helical) inserts for aluminum brackets, etc. We also use them in our shop and for aerospace and medical parts we produce. They are a fantastic insert and work extremely well.



EDIT - here is a cool back yard test video. Cool to watch

[ame]http://www.youtube.com/watch?v=LpDduCVUy6w[/ame]

 

Heli coil is a better repair. Ferrari has used them for 40 years in high torque applications or where a bolt needed to be used instead of a stud and they have been FAA approved for a very long time.

Threadsert has a very fatal flaw in the design. I will never use them.

 

When you say "threadsert" is that the same as "Time Sert"?

If so, what is the fatal flaw?

Thanks.

 

Naaah, it's a mower.. quick and dirty just use a quick-snap expansion plug..

J/K
Heli-coil to do it right.

 

For the curios

Heli-Coil® | Keensert® | Keysert® | Acme | Comparing threaded inserts

 

I would make the repair and then throw in a Fumoto valve.

 

Man has Valet parking in his garage and he frets about the price of helicoil..

 

If it seats with a copper or aluminum washer, make sure it is dead straight. On Ferrari tanks and pans, I have a spot face tool that I use after putting in new threads. This re-aligns the seal face with the thread. Any miss-alignment will be a leak.

 

I actually tried that. I bought a Fumoto for a Toyota (that is the same size, never installed) but the heavy skid plate on the mower is too close to the drain hole to spin it in.

 

Thanks for the tip. I suppose I will use fiber washers since I have no surface tool.

 

Wade's point is excellent. But, if you tap straight, it should not be an issue. Use a tapping block to guide the tap.

If you don't know what that is.....it's a block with a clearance hole (tight fit) for the tap to go thru. You hold the block up to the hole prior to tapping to keep the tap straight to the hole and perpendicular to the face.