Snapped valve cover bolt.

[Duporth]

1/4" or 1/2" have nothing to do with the torque rating.

It's just that the smaller torques like 9 ft-lb are likely to be more centrally located in the intended operating range of a 1/4" tool than a 3/8". 9 ft-lb is within the lower 5% of my 3/8" range !
D

 

[dwalby]

It's just that the smaller torques like 9 ft-lb are likely to be more centrally located in the intended operating range of a 1/4" tool than a 3/8". 9 ft-lb is within the lower 5% of my 3/8" range !
D

FWIW, when I bought my in-lb torque wrench Snap-On made the same wrench in 1/4" or 3/8" drive. I went with 3/8 because I had the same sockets in either drive, but had better quality ones in 3/8".

 

[Bmacleod]

It should be noted that as you get down to the lower end of the range of a click type torque wrench, especially the smaller inch-pound units that the click can get very faint on some units and it is easy to "miss"it and continue torquing up. I practice going slow and paying close attention for the click on my 3/8 inch pound wrench, especially on low torque bolts such as the valve covers.

 

[dwalby]

I never use a torque wrench on the valve cover bolts, they just need to be snugged up by hand because they bottom out on the head via a shoulder at the lower part of the bolt that's hidden inside the valve cover. The grommets determine how much pressure will be applied to the gasket by the valve cover after the bolt bottoms out. If for some reason your torque wrench doesn't release properly when the bolt bottoms out you'll strip out the threads in the head and be sorry you used the torque wrench in the first place.

Your caveat is the same regardless of why you had reached for a torque wrench. If the premise is true, then a torque wrench should never be used, because if it doesn't release properly then you risk damage from over-torque to the assembly. .... If you think you can manually gauge torque more accurately than a properly sized high quality calibrated wrench, you are deceiving yourself.

I just realized I forgot to mention the main reason why I don't like to use a torque wrench on this application, its not what you mentioned.

Most bolts act like springs when torqued, and you can feel a gradual and fairly linear increase in resistance as you tighten further. The valve cover bolts don't seem to act like that in my experience, they have a more 'binary' feel to them. The threaded portion below the shoulder is fairly short, so there's not a lot of threads. The feel tends to change from really loose to tight all at once when it bottoms out on the shoulder. I also suspect that the short thread engagement narrows the amount of available bolt rotation between just right and thread/bolt damage. If you're torquing manually you're paying full attention to feeling that engagement point and stop turning as soon as you feel it. If you're using a torque wrench you may not be paying as close attention, and by the time your brain realizes "this probably should have released by now" its probably too late because of the short threads. Just my opinion, as they say YMMV.

 

[myst1100]

Recap - I was able to drill a small hole and use an ezout to extract the broken part. I think the saving grace was that the bolt wasn't that tight due to the bottoming out of the flat part.

New gasket, all is well and thanks for all the suggestions.

 

[John OoSTerhuis]

Thanks for the followup, Bob. Always appreciated. Glad to hear the problem’s resolved.

John

 

[Jim Van]

I thought it would be easy to remove the broken off bolt - it wasn't that tight when it snapped off. Probably a defective bolt.

I only use a torque wrench to tighten critical bolts & nuts. The last time I used a torque wrench was to tighten the swing arm nut after I put two drops of red loctite on the threads, 180 degrees apart. For something like the cam cover bolts, I just tighten them by feel. One drop of low strength ( blue ) loctite could be used to make a person feel better, if they are worried about the bolt loosening.

I have never discovered a loose bolt or nut yet. And I haven't stripped a bolt or threads, yet. But maybe tomorrow it will happen because of my last sentence - any thing can happen. I might even test positive for the virus tomorrow - who knows ? But I hope not since being an old retired geezer on a fixed income that will put a financial as well as a physical strain on me.

BTW, if the threaded hole is blind, any liquid ( like oil ) can cause a hydraulic bind that can cause the bolt to snap off.

 

[Bikeric]

Glad you are now sorted out!

 

[SSBBS]

Greetings inmates, have read the thread about removing broke off valve cover bolts because i managed to make the mistake even after being cautioned not to by a real mechanic....massive brain fart on my part, beyond dumb.

the bolt is soooo skinny...I like the idea of left hand drill bit and the possibility it may back out using one, but i have never heard of such a thing before.
Any advice on where to get one of appropiate size, and I assume, based on thread, that cobalt is better bit to get? I have the bike on a lift table and all the tupperware off it, gas tank/radiator,everything removed...broken bolt is upper/forward right, looks like a clear shot at it, but man, does it ever look like one shot is all I got, so want to take every precaution...including that magnetic sleeve mentioned in thread, something else I have never heard of but like the idea of catching the shavings, so any help on where to secure one of those would also be welcome.

this bike is such a tank....road it back from where i had it stored in vegas to atl last year...it was leaking oil(valve cover gasket) and fuel( filter was toast) because it had sat untouched for 2 yrs after covid broke in a storage shed that i'm sure topped 130 degrees on more than one occasion....the LiOn jump starter i had stored in shed literally expanded apart and self destructed......the ST fired up with new battery and we sat on 85+ coming across texas on 2 lane to avoid the cluster F on I-40....it was almost comical whenever I stopped, the smell of gas and burnt oil coming off exhaust, it idled rough, but never died or failed to start and thankfully the actual amount of oil loss was nowhere near as bad as the smell implied...i was pleased to note it was still well within range when I drained it once getting it home,,,,i owe this bike the maintenance it deserves, and am also putting vinyl wrap on it, slowly learning how hard that actually is to do and just how many pieces of tupperware come off it when you pull them....paint was in bad shape, so it will look better, but wrapping is a slow hard roll is what i now know...i have mega hours invested and maybe 7 pieces done......not my main bike, thankfully, so still getting some wind and determined to get the ST1100 right with hopes of maybe getting it stored back out west again some day......bought it in denver, spent a few years storing/exploring the rockies on it, and decided to relocate it to vegas as a winter option just before covid shut everything down.....not sure we will ever see airfare that cheap again, but plan to be ready in case we do. Vegas is a great base....cheap lodging/food/booze and 3 hrs to kanab,UT where temp is 20 degrees lower...it was the right call, I just did not get the chance to get all of it....the ride from Denver to vegas was epic, hwy 12 down middle of UT was amazing, Grand Escalante to Kanab,Ut puts you striking distance from the north Rim....will get back there one way or another someday.

happy Trails to all!

gary

 

[Nashcat]

Find your left handed bits at McMaster-Carr. https://www.mcmaster.com/

Use a small, sharp punch to mark the center of the screw before drilling. After starting the hole, slow down the drill speed and apply more pressure, to let the bit “grab”. When the bit grabs, out it comes. McMaster is located in Atlantis.

John

 

[Tenmilsocket]

I picked up a set at my local Northern Tool the last time I had a broken bolt:

https://www.northerntool.com/shop/tools/product_200631741_200631741

 

[Andrew Shadow]

Were left-hand drill bits originally conceived of to remove right-hand threaded screws? As far as drilling holes goes, the direction the drill bit rotates in doesn't matter does it? So, if it wasn't for screw extraction, what was the original purpose of them?

 

[red one]

Just did a valve cover gasket replacement job on my Corolla and no torque wrench is needed. If you have worked with hand tools for a long time you know when it's just enough and just right. Anyway I used a quarter inch drive wrench and 10mm socket tightened till snug. Started it up the next day after rtv hardened where the timing chain cover and block meet and no drips, runs or errors.

 

[dwalby]

Were left-hand drill bits originally conceived of to remove right-hand threaded screws? As far as drilling holes goes, the direction the drill bit rotates in doesn't matter does it? So, if it wasn't for screw extraction, what was the original purpose of them?

you use right handed drills in the northern hemisphere, left handed in the southern, otherwise the Coriolis effect makes it harder to drill.

 

[SMSW]

Were left-hand drill bits originally conceived of to remove right-hand threaded screws? As far as drilling holes goes, the direction the drill bit rotates in doesn't matter does it? So, if it wasn't for screw extraction, what was the original purpose of them?

Andrew, left handed drill bits were originally made for use by left handed machinists and mechanics.

The early ones were made of anti-matter, but did not survive very long.