Drain plug tapped off angle

[wolfsburged]

Helping a friend who had cross threaded the oil drain plug on her motorcycle. The drain plug was M14x1.25 and was helicoiled, however it looks like the helicoil tap was run in slightly off angle. The result is that the bolt threads in fine but doesn't seat flat on the sump and therefore won't seal properly.

I'm trying to help and figure out easiest way to correct without major disassembly, etc.

Ideally if I had a tool that would allow me to easily mill a flat using a bolt threaded into the hole for a perpendicular reference, I think this would work as the pan is aluminum. Not sure if this exists? I could file and/or grind but in place I worry about accuracy and getting **** in the pan.

Suggestions?

 

[LXCam]

Is there enough meat to do a oversized plug?

Like this: https://www.cpooutlets.com/9-circle...uDvFI8YEX6OPV1-9uTC9DLjCOmw72gjxoCCA8QAvD_BwE


Or maybe better yet?: https://www.finditparts.com/product...ssdDPjQSTbr1sAIZ4G_STV2X00_bTa2hoCNhgQAvD_BwE


Another option would be to use a counter bore for recutting the flat. You'll have to search for the right size but you get the idea: https://www.amazon.com/dp/B00RY558JM/?tag=atomicindus08-20

 

[rsanter]

Use a softer seal that will accommodate the off angle

Silicone O ring should work, soft copper may work

 

[matt_i]

I think I would try to carefully file on the outside of the pan to create a new surface.

The chips are larger (not superfine like dusty grinding), there is no abrasive left behind, and you can flush the area with some clean oil sent in thru the normal filler.

I'm most familar with the soft gasket on GM oil pan drain plugs, these seem to work for quite a while. With copper there's a forevermore battle of having the right washer on hand or buying them in bulk to save but then forgetting where they are

 

[The Cobbler]

a soft pc of lead sheet would work to fab up a washer .

 

[scissorman]

Look at thread repair kit's made by time cert.

 

[jeepinerdeep]

The tool you are looking for is called a spot facing tool. It's used all the time in industry for plugs and ports in castings. We have one for threaded ports at the plant, hand powered. Salty.

A chinesium counter bore endmill in your cordless drill will probably be the most cost effective.

 

[Kmp259]

Eco Plug for aluminum pan works great.

http://yhst-137220973255828.stores.yahoo.net/test2.html

 

[gorilla]

If the hole is anyway close to a common pipe thread re drill it and tap it to a taper pipe thread. then the seal is made by the threads not the head pf the plug.
Another option would be to epoxy the drain plug in and change oil with a suction device.

 

[Bighead38]

How hard to change the pan?

 

[EdT]

I'd use a piloted counterbore and a threaded bushing with a hole in it sized to fit the c'bore pilot. You can get c'bores with interchangeable pilots. The bushing is to align the c'bore as well as possible with the axis of the hole and to avoid damaging the threads in the helicoil although that risk is pretty low. You'd have to balance it of against the risk of the pilot screwing the bushing all the way into the sump which would be bad. Depends a bit on whether the threads in the hole go all the way through or not. The bushing should have a slot cut in the end so that you can get it out with a screwdriver. the amount of material you need to remove to align the sealing surface with the axis of the new hole is probably not much so be careful not to get carried away. Put some marker ink or dykem on the existing spot face, that'll make it easier to tell when you're done. Marker ink does not stick to oil.