Big hole in aluminium oil drain plug

Big hole in aluminium oil drain plug

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ReverendCounter

Original Poster:

6,087 posts

175 months

Thursday 8th April 2021
quotequote all
Imagine this hex shape replaced by a ragged hole, with the rest of the aluminium plug still stuck fast in the sump.



Now imagine at least two of those ‘fins’ are missing due to a screwdriver and hammer being used on them.

Seeing as I’ve gone this far, how can I make it worse?

And if it can’t get worse, what can I do to get the fker out?


Krikkit

26,500 posts

180 months

Thursday 8th April 2021
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I'd take the sump off then drill/file it out.

ReverendCounter

Original Poster:

6,087 posts

175 months

Thursday 8th April 2021
quotequote all
OK, was under the impression there wasn't a bolt on sump but will look into that.

StreetDragster

1,513 posts

217 months

Thursday 8th April 2021
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Can you get some heat on it? A couple of heating/cooling cycles might help free it off.

gts.981

136 posts

44 months

Thursday 8th April 2021
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Make the hole a more uniform shape and use an Allen key.

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Original Poster:

6,087 posts

175 months

Thursday 8th April 2021
quotequote all
Krikkit said:
I'd take the sump off then drill/file it out.
Unfortunately no sump, it's in one half of the crankshaft case.

ReverendCounter

Original Poster:

6,087 posts

175 months

Thursday 8th April 2021
quotequote all
Will try heat, then modding the hole to take a tool of some sort if it doesn't work.

Olivergt

1,319 posts

80 months

Thursday 8th April 2021
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After the heat, you could try a stud extractor tool? You might have to drill out the hole a bit to get it nice and round.

Tango13

8,398 posts

175 months

Thursday 8th April 2021
quotequote all
Is there enough room to get a drill in there?

I'd be trying a left handed drill and going up a size in small increments until you reach the core of the thread then trying to get the remains of the plug out with something sharp and pointy

Edited by Tango13 on Thursday 8th April 17:19

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Original Poster:

6,087 posts

175 months

Thursday 8th April 2021
quotequote all
Olivergt said:
After the heat, you could try a stud extractor tool? You might have to drill out the hole a bit to get it nice and round.
Yep, I've even been thinking about what shapes would give the best friction/grip - including a large slot to take a thick bit of flat bar bent at 90 deg to act as a long lever/handle.

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Original Poster:

6,087 posts

175 months

Thursday 8th April 2021
quotequote all
Tango13 said:
Is there enough room to get a drill in there? ]
Yes but the problem is, the thread diameter is about 30mm



Jazzy Jag

3,412 posts

90 months

Thursday 8th April 2021
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What bike is it?

Looks like a Yamaha?

Use a Punch or small chisel on the outer part but be careful not to damage the engine casing.

Tango13

8,398 posts

175 months

Thursday 8th April 2021
quotequote all
ReverendCounter said:
Tango13 said:
Is there enough room to get a drill in there? ]
Yes but the problem is, the thread diameter is about 30mm


That makes it much trickier...

Time for plan 'B' which involves a brave pill and a carbide rotary burr, drill out as big as you can then use the carbide burr to open up the hole until the core of the thread is just showing. Then you can try ttting it with a hammer and cold chisel to try and break the remaining thread to get it undone.

Bee very careful though as the carbide burr won't be taking any prisoners and they can go through steel at a frightening rate never mind an ally crankcase!



tvrolet

4,251 posts

281 months

Thursday 8th April 2021
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Plan A, drill 2 holes either side and make up a bar with to 'pins' in it (like the sort of thing you'd undo a grinder disk with), put pins in holes and use bar to undo the plug.

Plan B, drill 2 holes either side and tap them; put to holes in a bar and bolt the bar to the plug then undo.

HustleRussell

24,602 posts

159 months

Thursday 8th April 2021
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Buy the special tool?

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Original Poster:

6,087 posts

175 months

Thursday 8th April 2021
quotequote all
Jazzy Jag said:
What bike is it?

Looks like a Yamaha?

Use a Punch or small chisel on the outer part but be careful not to damage the engine casing.
Yes, Yamaha 125

Tango13 said:
Time for plan 'B' .. brave pill…carbide rotary burr, drill out as big as you can … open up the hole … try ttting it with a hammer and cold chisel …
Given I can be a cack handed baboon at times, I might relegate this to plan Z due to an increase in desire to commit arson when things like your suggestion don’t go as planned.

But I do understand the approach, despite access being a bit difficult

tvrolet said:
Plan A, drill 2 holes either side and make up a bar with to 'pins' in it (like the sort of thing you'd undo a grinder disk with), put pins in holes and use bar to undo the plug.

Plan B, drill 2 holes either side and tap them; put to holes in a bar and bolt the bar to the plug then undo.
This is similar to my thoughts of a flat bar bent at 90deg at the end, going into a slot cut into the plug.

Your idea is better because it will lessen the likelihood of swarf inside the engine block which I’m obviously keen to avoid.

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Original Poster:

6,087 posts

175 months

Thursday 8th April 2021
quotequote all
HustleRussell said:
Buy the special tool?
This tool you speak of - tell me more.

KTMsm

26,765 posts

262 months

Thursday 8th April 2021
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Drill the hole until you're into the thicker alloy

Then find a suitable size torx and drill the hole slightly smaller than the torx, hammer the torx in

Heat the casing around the plug - I prefer a good heat gun rather than a torch as it's easy to damage the finish with a flame, then unscrew

Always worked for me

Or whack it a few times with a hammer then use a sharp chisel to start, then swap to a blunt one to knock it around

trickywoo

11,705 posts

229 months

Thursday 8th April 2021
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Irwin style bolt extractor, if it will fit over the big bit and between the raised flange bit.

Steve Bass

10,186 posts

232 months

Thursday 8th April 2021
quotequote all
tvrolet said:
Plan A, drill 2 holes either side and make up a bar with to 'pins' in it (like the sort of thing you'd undo a grinder disk with), put pins in holes and use bar to undo the plug.

Plan B, drill 2 holes either side and tap them; put to holes in a bar and bolt the bar to the plug then undo.
^^^^ This.

Drill & tap the flat bar with decent sized bolts (M6/8) into it, drill corresponding holes in the plug, insert and turn.
But definitely apply heat to the plug in the first instance and a bit of judicious tapping...

God luck