Stripped oil plug threads lower knuckle

[kevinshelton]

RTVX1140 right front knuckle. The oil drain plug was over tightened and now the threads are stripped in the knuckle housing. Gotta get this thing repaired in an hurry because this is what my wife drives the grandkids around on. If momma ain’t happy nobody is happy. Any thoughts on a quick GOOD fix?

 

[Connor]

I’m not sure if it will work on your application-but on a transmission plug someone stripped in the cast,
I had put a Helicoil in it for temporary fix.
grease your drill bit and grease the tap so it catches the metal shavings instead of them falling inside.

hope that helps some

 

[Connor]

Forgot to ask-is it pipe thread or a straight thread with o ring seal?

RTVX1140 right front knuckle. The oil drain plug was over tightened and now the threads are stripped in the knuckle housing. Gotta get this thing repaired in an hurry because this is what my wife drives the grandkids around on. If momma ain’t happy nobody is happy. Any thoughts on a quick GOOD fix?

 

[GeoHorn]

Helicoil and use a straight-thread plug with a seal.

 

[TheOldHokie]

RTVX1140 right front knuckle. The oil drain plug was over tightened and now the threads are stripped in the knuckle housing. Gotta get this thing repaired in an hurry because this is what my wife drives the grandkids around on. If momma ain’t happy nobody is happy. Any thoughts on a quick GOOD fix?

Run to your local auto parts and get yourself a heli-coil. Simple permanent fix.

Dan

 

[TheOldHokie]

Helicoil and use a straight-thread plug with a seal.

That answer confuses me. Helical thread repair inserts always match the original thread.

Dan

 

[Pawnee]

If you need it 'right now' there are oil pan drain hole plugs that go in the ruined hole and tighten up.
Like a rubber bung.
One of those will get you through Easter if that is the problem.

 

[GeoHorn]

That answer confuses me. Helical thread repair inserts always match the original thread.

Dan

Yes, and it will remove the stripped Pipe-threads (if that is what existed)…replacing them with new “straight” threads…. which will require an o-ring or copper washer to seal….. OR will seal a helicoil which is intended for mechanical strength….and sometimes does not properly seal fluids/pneumatics/etc.

 

[TheOldHokie]

Yes, and it will remove the stripped Pipe-threads (if that is what existed)…replacing them with new “straight” threads…. which will require an o-ring or copper washer to seal….. OR will seal a helicoil which is intended for mechanical strength….and sometimes does not properly seal fluids/pneumatics/etc.

If the strippef threads are NPT you use a helical pipe thread insert and tap and the repaired threads are tapered just as original. That helicoil may he a little harder tp get locally.

And just for general information American pipe threads can be either tapered (NPT/NPTF) or parallel (NPS/NPSF). Even harder to get taht locally.

Dan

 

[GeoHorn]

Besides not being locally commonly available, I don’t care for the fact that to install a pipethread helicoil… you must use a Straight-Sided drill bit…. but I “get-it” if that’s the preferred solution.

A solution I prefer would be to drill then tap it for the next larger plug. Here’s why: When I bought/was-gifted a 9N tractor the differential leaked all its fluid when the first time I used it the NPT drain plug simply “dropped out of sight” somewhere in the grass. (Suspect previous owner hadn’t tightened it and I didn’t bother to check it. I believe the plug was stripped because it would not accept a properly-sized replacement.

I went from a 1/2” NPT plug to a 5/8” NPT plug and never had another problem. (or maybe a 5/8” to a 3/4”…. I don’t recall exactly, I’ve slept since 18 years ago when this occurred.)

 

[TheOldHokie]

Besides not being locally commonly available, I don’t care for the fact that to install a pipethread helicoil… you must use a Straight-Sided drill bit…. but I “get-it” if that’s the preferred solution.

A solution I prefer would be to drill then tap it for the next larger plug. Here’s why: When I bought/was-gifted a 9N tractor the differential leaked all its fluid when the first time I used it the NPT drain plug simply “dropped out of sight” somewhere in the grass. (Suspect previous owner hadn’t tightened it and I didn’t bother to check it.)

I went from a 1/2” NPT plug to a 5/8” NPT plug and never had another problem.

News flash - NPT tap drils are straight sided. You then have the option - usually skipped outside of a production shop - to use a taper pipe reamer to finish the hole. The exact same situation exists when using an STI .

Personally I macine and hand tap a lot of holes and I own and use taper pipe reamers because they reduce the torque needed to run the tap into the proper L1/L3 depth. You get a more accurately tapped hole AND greatly reduce the chance of breaking the tap. That is another advantage of STI taps. Broken taps of any kind are a machinist's nightmare.

Dan

 

[number two]

Auto parts stores offer oversize oil pan drain plugs.
Self-tapping and available in one and even two oversizes.
Isn't that a decent "Good Fix"?
Good Luck!

 

[Motion]

I'm not a fan of modifying from original, consider removing the left side plug and getting the correct size plug and thread restorer. A tapered wooden will get you out of the woods.

 

[GeoHorn]

News flash - NPT tap drils are straight sided. You then have the option - usually skipped outside of a production shop - to use a taper pipe reamer to finish the hole. The exact same situation exists when using an STI .

Personally I macine and hand tap a lot of holes and I own and use taper pipe reamers because they reduce the torque needed to run the tap into the proper L1/L3 depth. You get a more accurately tapped hole AND greatly reduce the chance of breaking the tap. That is another advantage of STI taps. Broken taps of any kind are a machinist's nightmare.

Dan

I “get it” Hokie…and I appreciate your comment…. but the average guy is not going to have the expertise req’d to properly utilize a tapered reamer without running the risk of over-doing it and creating a larger leak. The solution I offered utilizing std helicoil and an o’ring or seal is more likely to result in success, in my opinion.
Not every owner is a qualified machinist or equipped with the tooling to attempt the perfect repair.
I do agree that a more sophisticated solution is elegant.

 

[TheOldHokie]

I “get it” Hokie…and I appreciate your comment…. but the average guy is not going to have the expertise req’d to properly utilize a tapered reamer without running the risk of over-doing it and creating a larger leak. The solution I offered utilizing std helicoil and an o’ring or seal is more likely to result in success, in my opinion.
Not every owner is a qualified machinist or equipped with the tooling to attempt the perfect repair.
I do agree that a more sophisticated solution is elegant.

More horse puckey. You have expressed your peference - I get it. But stick to facts rather than inventing mythical problems.

You dont need a reamer for this job - that comment was in response to your silly straight sided tap drill comment. And as I said that step is commonly skipped even for virgin threading.

The NPT helicoil is readily available and no harder to install than a UN insert - drill just a few thosandths over, retap with the STI tap provided, screw in the insert using a little liquid thread sealabt and you are done. Its also easier than drilling and tapping a new larger threaded hole of any type and keeps things OEM. When installed with a liquid pipe thread sealant it produces the same pressure seal as the virgin pipe threads.

Dan

 

[GeoHorn]

More horse puckey. You have expressed your peference - I get it. But stick to facts rather than inventing mythical problems.

You dont need a reamer for this job - that comment was in response to your silly straight sided tap drill comment. And as I said that step is commonly skipped even for virgin threading.

The NPT helicoil is readily available and no harder to install than a UN insert - drill just a few thosandths over, retap with the STI tap provided, screw in the insert using a little liquid thread sealabt and you are done. Its also easier than drilling and tapping a new larger threaded hole of any type and keeps things OEM. When installed with a liquid pipe thread sealant it produces the same pressure seal as the virgin pipe threads.

Dan

Your earlier response explains your animosity better:

That answer confuses me. ….Dan

 

[whitetiger]

Forgot to ask-is it pipe thread or a straight thread with o ring seal?

The thread is a straight metric bolt thread with a sealing washer. They are approx 10 or 12 mm.

 

[TheOldHokie]

The thread is a straight metric bolt thread with a sealing washer. They are approx 10 or 12 mm.

Are you sure its metric and not BSPP? Thats a pretty commonly used oil drain plug.

Dan

 

[Russell King]

Are you sure its metric and not BSPP? Thats a pretty commonly used oil drain plug.

Dan

View attachment 99759

That is a really good question and I don’t think that you can get an answer…
I know that Germany uses BSPP plugs made to some DIN standard.

“What does the metric world use for piping?” is another question that is similar.

I gave up on trying to figure that out and just use whatever matches the threads provided

 

[TheOldHokie]

That is a really good question and I don’t think that you can get an answer…
I know that Germany uses BSPP plugs made to some DIN standard.

“What does the metric world use for piping?” is another question that is similar.

I gave up on trying to figure that out and just use whatever matches the threads provided

Germany and parts of Europe are typically metric (DIN = Deutsches Institut für Normung eV). Asia and probably the majority of Europe is BSPP - legacy 0f the British empire.

Dan