Bolts 101

[bbelk]

So after stripping one of my drive shaft bolts, I took the transmission back out and dropped it off at the shop. For a little less than the cost of the tool, he is changing out the flange on the back of the transmission.

While I am waiting, I decided that I needed to put some locktight on the bolts that hold the clutch assembly to the flywheel. I chickend out the first time at around 12 foot pounds when I put it together. I pulled one bolt and was putting it back. Somewhere just over 10 foot pounds I heard and felt a pop. The bolt backed out easy enough, but it was clearly deformed. The threads look undamaged.

Knowing I was getting new bolts anyway - I pulled another one and put it in the vice. At 12 foot pounds it twisted off. The comparison is not quite right as the bolt was supported in the vice on only two sides rather and uniformly, but its still scary.

The book does not say anything about replacing these bolts. Is there some general rule that says I should? The book also says 17 foot pounds. Does anyone know if this is wrong?

[dougie]

Any chance that those bolts have been used many times, and someone else over-torqued them?
Any chance they are non-stock sub-standard bolts?

[bbelk]

Any chance that those bolts have been used many times, and someone else over-torqued them?
Any chance they are non-stock sub-standard bolts?

I got the bike 5 years ago in pretty good shape with 11,000 miles on it. I think I am the first person in there, so I don't think I can blame anyone.

[vanzen]

I got the bike 5 years ago in pretty good shape with 11,000 miles on it. I think I am the first person in there, so I don't think I can blame anyone.

The corners of the hex-head on that bolt do not appear "virginal" ...

A lot can happen in the course of 11,000 miles – some of that might not be good.
I once bought an RS with 1,700 miles, and by virtue of it sitting and not being ridden,
the rear main seal leaked oil. I replaced it soon after the purchase – I used a torque wrench ...

[George Ryals]

How long has it been since you had your torque wrench checked?

[bbelk]

How long has it been since you had your torque wrench checked?

I was using a super precision Harbor Freight ($19.95) click type torque wrench. I also own a 70s vintage Sears flex bar type wrench that I never trusted much. I never thought to compare them. I fitted the right socket on them and went at it in 5 pound increments up to 30 foot pounds. The Harbor Freight tool clicked a hair under the appropriate mark on the Sears tool.

[Ken in Oklahoma]

I was using a super precision Harbor Freight ($19.95) click type torque wrench. I also own a 70s vintage Sears flex bar type wrench that I never trusted much. I never thought to compare them. I fitted the right socket on them and went at it in 5 pound increments up to 30 foot pounds. The Harbor Freight tool clicked a hair under the appropriate mark on the Sears tool.

I'm a fan of a beam type torque wrench, mostly because you can count on it not "wearing". That is, a certain torque will always result in a certain deflection. Of course you have to make sure that the at-rest "zero" hasn't changed due to inadvertent bending of the little indicator bar. (My beam torque wrench is also a Craftsman, bought a very long time ago.)

Of course I seldom use my torque wrench, preferring to "feel" my way in what I regard as non critical applications, And if I were in the business, so to speak, using a torque wrench often, I would buy a clicker and check it regularly. That "click" is really satisfying and you don't have to stand on your head to see the torque indication.



Ken

[Deleted User 61]

Those are not bolts, they are screws.

Wasn't anybody else paying attention to Lonnie?

[Duane Ausherman]

We never measured the torque on the clutch screws. None ever gave trouble of any kind. That would be a sample of hundreds of clutch removal and installations. We just knew how tight that they should be. I was in the /2, /5 and /6 service schools and never saw them torqued, or mentioned that they should be torqued.

Of course this is considering mechanics that worked full time with tools. I think it helps a lot to do it everyday.

If we had removed a bolt like that one shown I would have known that somebody screwed up big time somewhere.

Am I the only one that just put them in without a torque wrench?

[Roy Gavin]

If you can locate a copy of the old Honda Common Service Manual on the net it has a good fasteners 101 -probably the best Ive seen for bike fasteners.

It seems to have vanished from the later versions of the manual- cant imagine why---.