Author Topic: Tool Knowhow  (Read 3755 times)

Offline DaveVA78Chieftain

  • 16 year member
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  • Posts: 3594
  • Member since: 2003
  • I own: I don't own one but I'm a vintage RV enthusiast!
  • Year: 1978
  • Make: Winnebago
  • Model: Chieftain
  • Chassis: Dodge M400
  • Engine: 440-3
Tool Knowhow
« on: May 01, 2011, 02:31 PM »
Sometimes you just need to know how to do something and the tool or technique seems a bit daunting.  Here is some nice to information and a view tips along the way.  Feel free to add your own information or tips.
Note: Most all of the pictures have a link to a full size version of the picture.



Just about any sort of mecahnical work requires you to delve into the mysteries of just how tight a bolt, nut, or screw must be tightned.  The proper term for how tight is torque.  Torque is normally measured in Foot-pounds but for smaller bolts may be specified in Inch-pounds.

When a specificatipn is given in foot-pounds, what that means is apply so many pounds of weight at a 1 foot distance away from the bolt center.  So, a specification of 50 ft-lbs means apply a weight of 50lbs at the end of a 1 foot long ratchet wrench.   A specification of 100 ft-lbs means apply a weight of 100lbs at the end of a 1 foot long ratchet wrench.

For small bolts, the measurement is typically given in inch-pounds.  This is nothing more than a smaller reference value where 1 foot-pound equals 12 Inch-pounds.  To determine inch-pounds when you are given a value in foot-pounds simply multiply the foot-pound value by 12 (10 ft-lbs = 120 Inch-pounds).

Many of the bolts and nuts used in a RV are very large and require torque values greater than the tools you normally have avilable.  In this case you have to be able to multiply the amount of force being applied.  This is done with a breaker bar.  You will also need to use the larger 3/4" drive socket set for these larger bolts and associated torque values.   Given that a torque specification is given in the number of pounds to apply at one foot distant from the bolt head, the same amount of force (in pounds) applied at a two foot distance doubles the amount of force applied at the bolt head (50 lbs at 2 feet distance = 100 foot lbs at the bolt head).  For every foot away from the bolt head you multiply the the amount of force applied times the number of feet away.

Here are some usefull reference pages from the Dodge Manual:

This dial measurement tool is one the most usefull tools I have ever used:

Used in conjunction with this table from the Service Manual: