Oil sump plug rounded, options?

[RR76]

I rounded the oil sump plug, a T47 bit. I have a new plug now but wondering the best way to remove the current plug. I was thinking of trying a reverse threaded drill bit?

If I screw it up though I'm essentially carless.

Any advice?

[Smurfsarepeopletoo]

Hammer a Socket onto it.
Hammer a bigger bit into it.

[gt40steve]

Stillson wrench.

[steveo3002]

small sharp chisel , dig it into the edge then hammer anitclockwise , once its moved a bit you can use pliers or whatever

or see if someone will put a dab of weld onto it for you ...weld a nut to it

[donkmeister]

gt40steve said:

Stillson wrench.

This would be my choice if there's enough protrusion for the teeth to bite and I couldn't hammer in the next size up torx bit.

The LH drill bit trick is unlikely to work if it's been done up tight enough to round it off, and extractors are a similar likelihood.

OP if you do use a stilson make sure to use it the right way round - I've seen someone struggle and assume the tool was useless when they were using it backwards. Best way I can describe the correct way is "the way that encourages the jaws to get pulled close together when you try to turn the wrench".

[guards red]

..or get some Irwin Extractors. Never failed to get off whatever I applied them to.

[Smint]

If safe to do so a bit localised heat together with Stilsons should do the job.

[Wacky Racer]

This happened on my Triumph Bonneville. I took the engine out and welded a small bar to it, came off easily.

Worst case, you could do the same by taking the sump off.

Good luck.

[Belle427]

Small sharp chisel for me is easiest, just don't swing at it with a lump hammer.

[cnprior]

I've used heat via a butane torch before and a combination of stillsons or molegrips (depending how much space there is around the sump plug.

If things get nasty, take the sump off - drill out the plug on a bench using a pillar drill (or get a local engineering shop to do this in extreme cases).......better than scrapping the sump or causing shavings to go-inside.

Chisels can work, but sometimes make a right mess and I have seen flat head screwdrivers hammered into splined sockets before now.....but I would avoid banging anything in there unless 'really stuck'.

[donkmeister]

Something else to check is that there isn't a build up of crud in the torx broach. I've gone to remove rounded off torx fasteners before, then noticed it looks a bit shallow. Poke around with a pick or awl and lots of crap has come out leaving a much deeper, not rounded hole for my bit.

Multiple times of people impacting dirt into the broach (or is it breach?) of the screw instead of giving it a quick clean first, until someone rounds it off.

ETA Broach is the tool used to make the hole. I've been using that word to describe the hole itself ever since a knowledgeable engineer used it that way. Seems that might not be correct usage, oh well

Edited by donkmeister on Thursday 12th January 12:48

[VeeReihenmotor6]

Irwin bolt extractors are great for anything like this. Saved me loads of times and will also get out rounded hex bolts too in seconds.

[largespiced]

If it was me I would leave it well alone and buy an oil extractor. Less messy and just as good

[DrDeAtH]

weld a nut to the drain plug. Then remove it with a 6 sided socket.

[LunarOne]

largespiced said:

If it was me I would leave it well alone and buy an oil extractor. Less messy and just as good

Not always. Some designs don't allow removing all of the oil via the dipstick hole, so you ending up adding new oil to old.

[Krikkit]

DrDeAtH said:

weld a nut to the drain plug. Then remove it with a 6 sided socket.

This would be my choice, let it go completely cold before trying to undo it

[Bainbridge]

largespiced said:

If it was me I would leave it well alone and buy an oil extractor. Less messy and just as good

This was exactly what I did when this happened to the Mrs's car, which I don't think had ever had an oil change since she bought it. Luckily the oil filter is accessible from under the bonnet so oil changes are a breeze.

[kev b]

Take it to a garage and any experienced mechanic will loosen that off in minutes.

Mechanics come across snags like this and worse, every day!

[VeeReihenmotor6]

kev b said:

Take it to a garage and any experienced mechanic will loosen that off in minutes.

Mechanics come across snags like this and worse, every day!

Yep with an irwin bolt extractor - I'd have it out in less time than it has taken to type this post. I weld too and wouldn't even bother firing up the welder for this type of job - yeah if it was rusted in to place but not a standard rounded bolt/hex.

[Decky_Q]

All I wanted to say is do not weld it unless you want a massive fire! (Oil ignition temperature is way below welding temps, look at how a waste oil heater works). Similarly advice to heat it with a torch should be taken with caution.