Stuck screw in clutch cover

[alexdecker]

Got a screw that's really stuck in there. Hit it what seems like way too many times and way too hard with the impact driver, but its not moving at all. Got some WD40 on that sucker as well. Next step is getting some heat on. Can I use a flame on the motor, or is that not advised? Any other advice for getting it out is appreciated. Its one of the long ones in the upper left corner of the clutch cover.

- Alex

[Oddjob]

If it refuses to move you could try some heat, it usually does help. Just don't go mad and melt the alloy  although to be honest they will stand quite a bit of heat. Just be careful if your not painting the engine or the paint will bubble off.

Failing that, as it's a long screw, drill the head off, remove the cover and you can then get some mole grips on the shaft that's left.

[alexdecker]

Alright, tried heat, and it is just not budging at all.

What's the best way to go about drilling the head off? Just put a drill through it, and drill straight into the engine case?

This is the screw in question:

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[McCabe-Thiele (Ted)]

Are you using a cordless impact driver or hand tools?

The beauty of cordless impact is you rarely chew up the head - Using JIS section bits of course.

[alexdecker]

Hand tools. A manuel impact screwdriver of this type: https://www.walmart.com/ip/Premium-Impact-Driver-Set-Manual-Reversible-Impact-Screwdriver-Kit-with-Metal-Case-14Pcs-Set-Screwdriver/838895016

[McCabe-Thiele (Ted)]

Hand tools. A manuel impact screwdriver of this type: https://www.walmart.com/ip/Premium-Impact-Driver-Set-Manual-Reversible-Impact-Screwdriver-Kit-with-Metal-Case-14Pcs-Set-Screwdriver/838895016

Back in the 1960's when I worked on my Honda 250 Dream I always ended up with one or two that would not budge - I used to drill out the screw head then with the cover off use a stud remover. Even that could be problematic as then the casing was often stuck to the bolts.

I wonder if a freezing cycle like plumbers use on water pipes might help?

.https://www.zoro.co.uk/shop/not-categorised/not-categorised/pro-freezer-spray-500ml/p/ZT1289374P?utm_source=google&utm_campaign=pla%2B%7C%2BNot%20Categorised&utm_term=ZT1289374P&utm_medium=pla_css_2&targetid=pla-293946777986&loc_physical_ms=1006674&dev=c&gclid=Cj0KCQiAxoiQBhCRARIsAPsvo-wF5IAwBCHVU-IuXqMyhw1Nq3XPTtp3_Sc5KFPGAkpbeebj6ZGmd_UaAgAtEALw_wcB

[alexdecker]

But when you drill it out, so you just put a metal drill directly through the screw, and then that's it? I can't picture how that is helping?

[McCabe-Thiele (Ted)]

But when you drill it out, so you just put a metal drill directly through the screw, and then that's it? I can't picture how that is helping?

I used to use an oversized drill or even a countersink bit so you are just drilling off the screw head leaving the scew shaft intact.

Something that can work is putting back the screws adjacent to the stuck one and tightening them up again - then try your manual impact tool again - I have found cordless impact tools much more effective than the manual ones due to the way they apply the turning force with the impact so quickly and repeatedly without coming out of the JIS head.

[philward]

Can you get all the other screws out Alex? If so, if you drill the head off the 'stuck' screw, you can then withdraw the case leaving a (headless screw). I use a cone shaped rotory bear in the cross of the screw head to take the edges off before starting to drill - to prevent the drill catching. Then start with a 3mm drill going upto 6.5mm/7mm - drill carefully and the head of the screw should come off.
The next stage of the process is obviously to remove the remaining headless screw. When applying a grip such as stilsons (grip better than molegrips), quite often the force applied from one side (ie, the lever of the stilsons) twists the stud and will shear the stud - so if you can get 2 stitsons and apply at 180 degrees, you will have equal force applied to the stud which will minimimise the chance of shearing - it may still shear.
If it shears, the next stage would be to cut the stud flush with the crankcase (carefully so as not to mark the mating surface), and drill out he screw from the crankcase/and/or helicoil - but lets take one step at a time!

[alexdecker]

I finally got it out! By drilling it out. Fortunately it was the only one (on the clutch cover - knock on wood). Haven't gotten to battle with the vice grips its, but doing to in a 180 format is good advice! Thank you! Hopefully it will come out rather pain free …

[philward]

Grip as near to the crankcase as posible (careful with the mating surface) to minimise twisting along the length of the headless screw.

[McCabe-Thiele (Ted)]

A stud extractor of the type with the three offset rollers works well on removing studs. You can get metric sets that are not too expensive - they last for decades if not abused.

[alexdecker]

This is where I am at. The vice grips are NOT gripping hard enough, and I am starting to loose my faith. Tried to in a 180 pattern as well. This thing is seized like nothing I've ever tried before.

Am I looking a drilling and rethreading, or how would you guys go about it?

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[philward]

You need a 'stilson' wrench' Alex - mole grips won't grip enough - the more you turn, the more they grip. You'll obviously need a small set to avoid the clutch basket

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[alexdecker]

Well grips doesn't matter now… Seriously, this is pissing me off. How do I drill this out? Can I even do that without breaking threads, engine casing etc?