Startling Discovery

[Bounce]

Anyone have a line on a good calibration company?

 

[MCRIDER007]

A month ago I took my final drive off my FJR, removed the drive shaft and universal to lubricate and clean while a new set of PR4s were being installed for my trip to Eastern Canada. I reassembled everything and verified that all torque specs were followed during reassembly. I took a checkoff ride and everything seemed great. The trip to Eastern Canada was nine days and 4,500 miles. Today I decided to wash the FJR and it was just a mess from the roads. When washing the back of the bike I looked down and froze where I stood. I couldn't find any crown nuts on the bolts which hold the final drive to the swingarm. I reached down and felt the inner most bottom nut and it was still there. I am shocked and feel fortunate to have gone such a long way and still be here to tell about it. If that final nut had come off on the interstate, well, lets just not think about it.

Only other time I've heard of this happening is when the nuts weren't tightened...

I think George is referring to me because I did fail to tighten the nuts after a tire change/spline lube and after a fairly long test ride at highway speeds I eventually (maybe a couple of days later) discovered that all 4 nuts were missing. It certainly wasn't obvious looking at the rear drive, even with the saddlebags removed, because everything looked normal. There weren't any gaps between the swingarm and pumkin, and after thinking about it....a lot....it appears that the rear tire when pushing the bike forward also pushes the pumkin into the swingarm, effectively doing the same thing that the tightened nuts do. I certainly don't recommend ignoring the nuts but think its unlikely that the absence of such is going to result in a sudden failure and the only torque required is enough so that the nuts don't vibrate off.

 

[Fred W]

Anyone have a line on a good calibration company?

How about in your own garage?

 

[infrared]

TechJunkie,

Okay, after a few years of maintaining military planes, I like torque wrenches. I know that you need to set the torque wrench to a value somewhat below the intended value, and "exercise" the clicker mechanism (for torque wrenches that click) several times before the final use. Then you can set the final value that is spec'd, and get fairly good results on your work. Store torque wrenches as detailed in the manual, not set at any torque value that you use.

After a few decades of flying hang gliders, I really like safety wire. Not for everybody, of course, so suit yourself, but it really improves my peace of mind. In case this incident might ding your own peace, I have a suggestion. You can drill the acorn nuts for safety wire, as seen below. Any decent drill bit larger than 1/32" (0,8mm) and smaller than 1/16" (1,5mm) will drill a nice hole for .032" safety wire.

All IMHO, naturally.

Cheers,

Red

 

[Cav47]

With all the aluminum on the bike I like torquing most things to specs in the manual; overtightening and stripping something is my fear. I almost always find that just as I'm thinking "that feels about just right" the wrench clicks. I splurged a while ago and bought a $120 torque wrench that I trust is pretty accurate, and I'm very careful with it so it will stay that way.
I really find it hard to believe that those nuts were at 30 lbs with the lock washers and tightened evenly that they spun themselves off after 4500 miles. Something else is going on here.....

I would start with "Righty-Tighty, Lefty Loosey".

In all seriousness, if I was torqueing bolts down that made a difference in safety like many of you do, I would go out and buy a well calibrated wrench. But I am not, so $120 dollars is going in my tank towards EOM!!!

Glad you survived. As someone has said before YMMV on this and almost any other opinion based topic on this board.

 

[Spud]

I enjoy the little ritual of checking everything with a final torque at the end of a job. I'm never in a rush when I work on the bike. Getting out my prized torque wrench (the most expensive hand tool I have or will ever buy) and clicking it through the parts I think deserve it gives me peace of mind when I'm flying down the road in the middle of nowhere. 70K miles of flogging the bike pretty hard and it runs great, has never let me down, has all of the parts it came with, and I've never had a single stripped anything. Works for me!

 

[Bounce]

I spent too much time in jet engine refreshing at Tinker AFB to ignore all the torques.

 

[Pterodactyl]

I pulled into my shop yesterday after a 640 mile ride and saw that the right muffler was no longer attached except at the connection with the exhaust pipe. The muffler dropped about 6 inches and rotated about 60 degrees; luckily it stayed on. I have Canyon Cage pannier protectors, so the fact that the bolt came off is on me. The bolt must have fallen out only a short while before we got home. It was very noticeable. I think Annie, who was following me would have seen it, as would I during a rest stop we took about 30 miles out. Replaced the bolt and have both sides double nutted.

 

[odot]

DCMA says if you double click the torque wrench you have over tightened the bolt/nut. They also say if you don't follow exactly what the manual says you are in fault.

If you don't follow your.....common sense....then you can sue someone. Good luck with your endeavors.

 

[mcatrophy]

I don't use a torque wrench, I use the "pinch test"

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(Click on image for larger view)

 

[HotRodZilla]

WTF did you do to your finger?

 

[mcatrophy]

WTF did you do to your finger?

When reassembling my drive shaft, I supported it with my hand underneath. It was initially reluctant to slide home, then it snapped into place all of a sudden. Unfortunately my finger was partially in the way, so my skin got somewhat pinched.

Reported for the usual general derision here.

 

[HotRodZilla]

Haha...Now I remember. I even commented about how that hurt back then. Hope you're better now!!

 

[Steel_Gin]

Is it possible it wasn't seated perfectly then while on the road things could have moved forward say a 1/16 (or less) of an inch and things came loose?

 

[mcatrophy]

Haha...Now I remember. I even commented about how that hurt back then. Hope you're better now!!

Never really a problem as it was my left hand and I don't have a clutch lever . Note the nuts were back on before I stopped to take pictures, the bike obviously takes priority. Or maybe I wanted the nuts on to stop me doing such an idiotic thing again.
Healed very quickly, unlike my ankle, which still isn't fully better after exactly five months to the day. Ligaments take a lot longer to heal than flesh.

 

[escapefjrtist]

Is it possible it wasn't seated perfectly then while on the road things could have moved forward say a 1/16 (or less) of an inch and things came loose?

Not likely if the nuts were tightened at all. As mcatrophy learned...the FD slides home pretty easily once lined up.

--G

 

[FJR Flyer]

Possible that you used the settings on the torque wrench for N-M vs ft-lb?

 

[TechJunkie]

Is it possible it wasn't seated perfectly then while on the road things could have moved forward say a 1/16 (or less) of an inch and things came loose?

No, it was firmly seated and verified. Ran all of the nuts snug and loosed and then snugged them again before torquing.

Possible that you used the settings on the torque wrench for N-M vs ft-lb?

I verified the settings on the Torque wrench and torqued it, backed off and re-torqued. I believe I just used the wrong toque setting and vibrations let them back off. I am sure it was my fault one way or the other.

I now have new nuts and washers and I will be sure everything is perfect. The torque spec I have this time is 30 ft-lb.

Thanks for all of the replies. First time I have had an issue like this on a machine I have worked on. Startling discovery to say the least!

 

[odot]

Hey, um, why back off then re-torque? Isn't that kinda wearing the threads down a bit more?

 

[mcatrophy]

Hey, um, why back off then re-torque? Isn't that kinda wearing the threads down a bit more?

Helps gorilla mechanics to squeeze the dirt out that they should have cleaned off before reassembly

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