Torque specs and manual info

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CNC

Torque specs and manual info

#1

Post by CNC » Sun Jan 22, 2006 10:27 pm

I'm using the Clymers manual and can't find torque specs for the rear motor mount bolts, front motor mount bolt, top motor mount bolt. Also, which manual is better than Clymers? Which one has torque specs?



Cotten
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Re: Torque specs and manual info

#2

Post by Cotten » Mon Jan 23, 2006 1:12 am

CNC!

Nearly any other manual is better, although the "Haynes" series was barely better only maybe.

Cut to the chase, and get reproductions of original literature.

As far as torque specs, Pan era manuals didn't address them. In simpler times, folks had cultured instincts about how to pull on a wrench.
Later manuals have generalized tables listing grades, sizes, and hash marks, but in real life the last word is your own feel. A discount torsion wrench helps take out the guesswork just fine.

...Cotten

Jack_Hester
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Re: Torque specs and manual info

#3

Post by Jack_Hester » Mon Jan 23, 2006 2:38 am

Cotten is right about the manuals and the manner in which torques were applied. Flywheels are the about the only thing that I use a torque wrench on. Everything else, I use my fingers as my guide. I begin snugging bolts, taking out the slack as I move back and forth. When I reach a point of no slack, from a moderate pull, I begin again with a little heavier, taking out the slack as I move from one to the other, until I've tightened to my satisfaction. Each component on the engine has it's own needs, as to how tight. Motor mounts would be different from head bolts. The motor mounts will not have a drastic temperature change. And, are metal to metal. Head bolts see an extreme change, and are used to compress a gasket (in most cases). Plus, if you ever build a Flathead, you have to be careful as you are tightening into cast iron threads. And, these must be snugged more than once. Several times, during my break-in process. And, rarely on a hot engine. My final checks are on a hot engine. But, most of the time, I find that they are already tight from the several run times that I snugged them on just a warm engine. And, these times are before it ever leaves the shop.

Jack

Cotten
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Joined: Mon Aug 26, 2002 9:09 am
Location: Central Illinois

Re: Torque specs and manual info

#4

Post by Cotten » Mon Jan 23, 2006 3:31 am

I think the word that best describes torquing technique is "creep".

As you draw up the slack, a well-lubed fastener slowly moves under steady pressure, 'creeping' up to it's hold at that amount of tension. A torsion wrench allows you to monitor your applied force accurately; but for small fasteners, a patient draw and natural intuition should do fine. If it starts to turn to butter, stop immediately and replace the bolt!

Big fasteners like crankpin nuts will demand more and more force as you get older.

...Cotten

harleydoug

Re: Torque specs and manual info

#5

Post by harleydoug » Sat Jan 28, 2006 3:22 pm

The really old service manual had some pretty interesting torque specs in them. "Two firm blows with a slugger wrench"or "a firm pull on a torque bar". Not to forget the compression test of "reasonable resistance on the step starter, while turning it over".
It's all a matter of experience and getting the "feel" of tightening bolts and fasteners.
The H-D service mauals change from year to year, but they are the mose comprehensive ones as far as torque specs goes. The Haynes and Clymers are very thorough in descriptions, but for the detailed specs, I find the Harley reproduction manuals hard to beat.
Keep them old dogs barking

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