View Full Version : Torque wench extension??

Jack K
01-19-2007, 04:15 PM
I saw on another post on this forum a reference to the use of a torque adaptor when tightening cylinder heads (or maybe it was torque plates) and it reminded me of an unresolved question I have about the use of those things.

I understand the formula for calculating the torque setting of the wrench to compensate of the additional length of the adaptor, but does this apply if the adaptor extents to the right or left at, say, 90 degrees, or 45 degrees, or even 120 degrees.

I've used these torque adaptors for years on Harley OHV's assuming the angle of the extension made no difference and have had no trouble with blown headgaskets or warped heads but I don't know if I've just been lucky or if my assumption is correct.

Anybody know the correct answer???

T. Cotten
01-19-2007, 10:08 PM
If the extension makes a right-angle from the fastener, to the head of the wrench, to your hand, the wrench reading remains reasonably accurate.

Your wrench does give you reading, right?


01-21-2007, 06:42 PM
Not exactly clear what sort of adapters you are talking about. But if any of these increase the straight line length from the handle of the wrench to the rotational axis of the fastener, then you will need to use a correction factor, as you will be applying a higher torque than what the wrench indicates.

T. Cotten
01-21-2007, 07:03 PM
If the adapter make an acute angle, it divides the reading!

Just always stick the adapter on at 90 degrees and you don't have to do any math.

The adapter can be any shape as long as it ends up square to the wrench.
Attached is a photo of my arsenal for Chiefs (barstock) and HDs (obstruction wrenches).

By flip-flopping the obstruction wrenches to either end of the cheapo torquewrench you can reach both headbolts and (with a 5/8" allen socket) basenuts for an accurate snug.

Adapter torsion is a minor inaccuracy, when even-ness of fastener stress is paramount.


Jack K
01-22-2007, 12:18 PM
Thanks for the input Cotten. I guess I've gotten away with what I've been doing because, as you say, uniform stretch on the fastner is paramount and the adaptor I'm using is short enough that it isn't changing the torque that much. About 4 lb. fully extended with the wrench I'm using.

What I'm using is the Snap-On 2" spline box-end on one end and a 3/8" square drive on the other. When hooked to a 3/8" drive clicker (I know, you don't approve) I can get to all the head bolts on panheads and shovelheads just by swinging the adapter around to gain access. By flipping the spline box-end over you can gain a little more clearance, kinda like flipping the clutch throw out lever on an Indian over.