Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: alexdecker on February 07, 2022, 06:22:42 PM
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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
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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.
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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:
[attach=1]
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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.
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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
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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
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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?
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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.
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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!
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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 …
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Grip as near to the crankcase as posible (careful with the mating surface) to minimise twisting along the length of the headless screw.
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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.
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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?
[attach=1]
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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
Sent from my moto g(50) using Tapatalk
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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?
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Something wrong there Alez, far too much thread showing, it may have been really badly cross threaded and that's why it was so locked.
Should have tried heat at the same time as the grips, most things will move that way.
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Something wrong there Alez, far too much thread showing, it may have been really badly cross threaded and that's why it was so locked.
Should have tried heat at the same time as the grips, most things will move that way.
Oh I did, I really did. I blasted it with fire. It just kept its place. Not sure what to do now though… actually never tried a screw that sat in there so tight and seized up.
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You can try and drill it out but it will probably end up needing an helicoil or something similar.
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Spark erosion will work. Search to see if there's anywhere near you.
Alternatively, a good welder may be able to weld a bolt onto what's left?
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I think if its stuck in that bad, welding anything will just end up with the same situation as before.
I think your only option is drilling it out. You need a good flat surface to drill and the key is a good central starting point - use a spring loaded centre punch to punch dead centre of the screw. Use a good quality Colbalt drill in a variable speed drill, starting at 3mm going up to the 6mm tapping size (5.0mm).
To reiterate, the key is drilling central and square as if you are off centre, the drill will go to the softest material and vere towards and grip into the alloy case.
Going straight to the helicoil option gives you more tolerence as you will drill the entire screw out when using the helicoil tapping size drill - you have more tolerence in being slighly off centre. Always good to have an M6 Helicoil kit in your tool kit as it will always come in handy.
Don't get too down about it Alex, we have all been there.
Maybe worth looking on Youtube to see the helicoiing process to give you confidence
Hope that helps
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si no te sientes seguro de resolverlo , dejalo , agrega un poco de sellajuntas y tal vez no pierda , algun dia lo quitaras con la destreza y herramientas adecuadas
if you don't feel confident in resolving it, leave it alone, add a little sealant and it may not leak, one day you will remove it with the right tools and skill.
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si no te sientes seguro de resolverlo , dejalo , agrega un poco de sellajuntas y tal vez no pierda , algun dia lo quitaras con la destreza y herramientas adecuadas
if you don't feel confident in resolving it, leave it alone, add a little sealant and it may not leak, one day you will remove it with the right tools and skill.
Yes, I was honestly thinking about that as well. But still. I have the whole engine apart, so might as well to it now. Anyways, it broke off at a point where I can still take the rest of the engine apart, so I'll do that for now :)
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If there is enough sticking out, get a slightly bigger nut and get it welded on with plenty of weld in the nut.
The heat from the welding will be far more than you put on it before and more direct, this normally breaks the bond between the bolt and the case.
Never failed for me :)
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If there is enough sticking out, get a slightly bigger nut and get it welded on with plenty of weld in the nut.
The heat from the welding will be far more than you put on it before and more direct, this normally breaks the bond between the bolt and the case.
Never failed for me :)
I considered taking it to a welder for exactly that. But hard to imagine anyone else putting more stress on it than I have already. Id be worried enough is sticking out to weld it without hitting the surface, which needs to be kept clean so it can still seal. But will have to see what others can do. It would seem I am out of my own league on this one :(
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Once you have stripped the engine completely, try clamping the stud in a vice, apply lots of heat to the case at the stuck end of the screw and turn the whole case, it may just give you enough leverage to break the bond. What heat source are you using? A normal little hand held gas cylinder like plumbers use will be of no use. You need a proper gas cylinder or even oxyacetylene.
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It was at this stage with my cylinder head that I wimped out and took it to the local engine (car) shop, I tried the hot cold, treatment, the violence, the penetrting oil but when I ended up with a stud broken off flush I knew it was time for me to quit, the cost of taking it to someone else was peanuts, the cost if I messed up would have been far greater.
(https://imagizer.imageshack.com/img923/8749/cptBxZ.jpg)
Cheers
Dennis
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It was at this stage with my cylinder head that I wimped out and took it to the local engine (car) shop, I tried the hot cold, treatment, the violence, the penetrting oil but when I ended up with a stud broken off flush I knew it was time for me to quit, the cost of taking it to someone else was peanuts, the cost if I messed up would have been far greater.
(https://imagizer.imageshack.com/img923/8749/cptBxZ.jpg)
Cheers
Dennis
Seems like the exact stage I am at right now Dennis!
Did he get it out with threads intact, or how did your situation end up?
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For your clutch one Alex, if you can get a nut (10mm) onto the stud, then get it welded to the stud down in the recess to fully bond the nut and stud together and effectively give you a bolt.
Then, don't try to undo it with torque, use a drill/screwdriver (specifically not an impact driver) and use it with a socket adaptor to persistently rattle the stud anti-clockwise. It may take time but it should eventually and gently loosen the stud. The heat from welding it will help too.
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If as it appears you are stripping the whole engine down I would press on with the dismantling see if any other bolts are going to be difficult then see if any other engineering jobs need doing then decide if it worth going to an engineering firm to get any issues that arise done.
FWIW I could not get the big Crank case bolts undone as my cordless impact gun did not have enough torque for the larger bolts. A friend came to my assistance with his Mulwarkee Industrial Cordless Impact tool and they all came out easily. A local engineering firm put a pair of Helicoils in the casing for the tensioner arm as I did not trust myself to do them. (One was stripped)
I even bought a spare casing as insurance just in case it all went wrong. Nice to have a spare if I ever needed it - it came in handy when I had an issue with gearshift movement as a comparison and source of gear parts that I did not use in the end.
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It was at this stage with my cylinder head that I wimped out and took it to the local engine (car) shop, I tried the hot cold, treatment, the violence, the penetrting oil but when I ended up with a stud broken off flush I knew it was time for me to quit, the cost of taking it to someone else was peanuts, the cost if I messed up would have been far greater.
(https://imagizer.imageshack.com/img923/8749/cptBxZ.jpg)
Cheers
Dennis
Seems like the exact stage I am at right now Dennis!
Did he get it out with threads intact, or how did your situation end up?
Drilled out and an insert fitted, the bike had sat for ten years and what had started out as a quick turnaround ended up taking me two years, luckily when I took the top end apart the only thing that needed attention apart from the stud was one stuck piston ring
(https://imagizer.imageshack.com/img923/7606/EhlJ1R.jpg)
Cheers
Dennis
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Not so much wimping out Dennis as working within your capabilities and knowing the consequences if you push yourself too far.
Sure we need to push ourselves to make progress with our skills set with the proviso that If it goes wrong we can find someone to fix it afterwards.