## Torquing Large Fasteners

This is a question that comes up pretty regularly so I thought it would
be wise to address it on this page. The question is how to torque large
nuts such as the rear axle nut or the flywheel gland nut without having
a torque wrench. Accurate torque is important for these nuts, and
luckily there is a way to do it without a torque wrench.

First, you need the proper tools. The rear axle nut for the air-cooled
cars is 36mm, and for the Buses/vans it is 46mm. The flywheel nut is
also 36mm on Type 1 engines. So, the proper tool here is a 6-point 36mm
and/or 46mm socket, ideally welded to a 6-foot long piece of cheater
pipe (basically a thick, heavy pipe to give the leverage necessary for
the task). Bob Hoover has a 6-foot long pipe with a 36mm socket welded
to one end and a 46mm socket welded to the other end.

The proper use of the tool can be found through some very simple math.
First you need the torque specification for the particular nut. Check
your Bentley manual. Let's say for the sake of example that the torque
spec for the rear axle nut is 300 foot-pounds. And let's say for the
sake of example that you weigh 150 pounds. Well, you simply divide the
300 foot-pounds by the 150 pounds, and that gives you 2 feet. The two
feet is the distance from the center of the nut that you will apply
force. So go out two feet on your cheater pipe. Make a mark at the
2-foot point and put one hand on either side, right up to the mark.
Then push down and keep pushing steadily until your feet clear the
floor. Don't jump up and down on it or anything like that. That will
give you the proper torque. Then you have to make sure that the hole
for the cotter pin is aligned so go tighter if you have to, not looser,
whichever is closer, to get the holes lined up and there you are.

Now that you know the mathematical relationship, you can simply
substitute the real numbers into the equation for the example numbers
above.

Back to the tech
page.