Transfer box level plug

[DGG]

I'm currently in the process of stripping down and rebuilding my transmission in my 61 109 Station Wagon. The level plug in the transfer box did not want to come out, so I drilled it out, but not completely. There is still the very outer ring of the fill plug in the hole. My question is what should I do next?

I'm thinking that I try to get the last remnants of the fill plug out without damaging the threads on the transfer box fill plug hole(sounds difficult), or drill the hole to a bigger size and tap it to fit a gearbox level plug.

The gearbox level plug is 1/2in BSF. What size hole would I drill, and would that work? Would it mess with the oil level in the transfer box because it is a little bigger?

Thanks.

[64Blue]

Can you get on it with an easy out? Alternatively I've drilled out studs before just to the point where only the "male " part of the thread is left and the grabbed one end of the threads and uncoiled the wire like a spring. Have to be very careful when drilling and the when using the needle nose pliers to pull out the "wire"


or, heat it up so it's getting real hot with a propane torch then take a can of freeze off or flip a can of computer cleaner air upside down and douse it to freeze it. Thermally shocks it which should then allow you to use the easy out. In thinking about this more, I would do that before I drilled it further and tried to pull out the threads.

[lumpydog]

Can you get on it with an easy out? Alternatively I've drilled out studs before just to the point where only the "male " part of the thread is left and the grabbed one end of the threads and uncoiled the wire like a spring. Have to be very careful when drilling and the when using the needle nose pliers to pull out the "wire"


or, heat it up so it's getting real hot with a propane torch then take a can of freeze off or flip a can of computer cleaner air upside down and douse it to freeze it. Thermally shocks it which should then allow you to use the easy out. In thinking about this more, I would do that before I drilled it further and tried to pull out the threads.

This is great advice. In the past I've used the needle nose pliers trick and pulled out the wire/thread remnant. But thermal shock will make that easier.

[SafeAirOne]

Since the transfer case is already out and empty of components (presumably), I'd take it to a machine shop and spend the $30 to have the professionals remove what's left of the plug before you get into worse trouble than you're already in. Its a comparatively hard steel plug in a comparatively soft aluminum case. If you botch this, it's the case that's going to get messed up permanently.

[DGG]

So you wouldn't recommend drilling it out bigger to fit the gearbox plug?

[DGG]

I got it out. Hopefully didn't damage the threads too bad. I'll buy a new plug and see. Should I maybe run a like size tap through it just to clean it up and straighten out the threads? Maybe a good idea to put some Teflon tape on the new plug.

[mearstrae]

Remember that British Standard Pipe thread (BSP) isn't that same as (American) National Pipe thread (NPT). And they're both tapered threads. I'd use a liquid teflon sealer on the thread, better in the long run than tape.

'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III Hybrid 109
'70 Rover 3500S

[64Blue]

I got it out. Hopefully didn't damage the threads too bad. I'll buy a new plug and see. Should I maybe run a like size tap through it just to clean it up and straighten out the threads? Maybe a good idea to put some Teflon tape on the new plug.

I think it always helps. Straightens out threads and prevents galling. Teflon, Teflon tape or anti seize is perfect. This only reduces the coefficient of friction to allow for a tighter bond without material failure. It actually doesn't act as a sealer. Tape might get chunks in the oil, so I'd steer clear.

[SafeAirOne]

I think it always helps. Straightens out threads and prevents galling.

Yes and No. A less-common roll-forming tap will straighten out/restore the threads, but a (much) more common cutting tap will "clean up" the thread grooves by cutting away any damaged aluminum thread material that has been bent over into the thread grooves.

[o2batsea]

Weld a nut on it. or weld in a hunk of 1/2 square stock if it's that type. That will not only serve to loosen it it also gives you something to put a wrench on.

You could also use an expanding rubber plug instead of the pipe bung.