How to Use a Torque Wrench

Hey everybody, it's Mike Roen with Fix My Hog. We're going to have a little tech tip for you today about torque wrenches, because let me tell you, I got a lot of customers, you know, they're smart engineers, whatever, and they go out and buy a torque wrench and they start torquing everything on their motorcycle. That can be a problem cause there's a variety of different torque wrenches, you know. If you look at these torque wrenches here, this is a half-inch torque wrench. You're not going to be torquing your drain plug with this torque wrench.

You know, this is for really heavy duty stuff. And the thing with torque wrenches is there's a range there, you know, within their parameter. So you've got to kind of look at what you're tightening, what you're torquing to as far as foot-pounds or inch-pounds. And you've got to pick the appropriate torque wrench for that purpose. So the number one problem is drain plugs because everybody says, "You know what?

I don't want to screw my bike up. I'm going to buy a torque wrench and I'm going to torque my drain plug to spec and then there won't be a problem." Well, what happens is, they get a torque wrench that's pretty much at the threshold of the low side of its range. So it turns out to be a big lever on it. And of course they always want to go max spec on it cause they don't want the drain plug falling out. So what happens is they end up stripping out their drain plug and it becomes very expensive.

If you've got an oil pan on a touring bike, you gotta drop the wheel out, you gotta buy a new oil pan, you gotta put it on. It's not cheap. Next thing is the inner primary, same thing. You strip that out, call it a $1000 day. You know, you could have brought it somewhere and had your oil changed quite a bit for that.

So really you want to kind of stay within that happy zone of the torque wrench where it's at. And you know, here's an inch-pound one and that might not be a bad idea for, you know, stuff that you're going to be torquing repeatedly like the drain plug. You go to your manual, you look and they list, you know, the small stuff, the little quarter-20 stuff, it's usually in inch-pounds because they don't want you messing around with a torque pound, you know, torque wrench. And another funny story is you got to look at the torque value. And I don't know why on an American-made motorcycle they list Newton-meters, but they do.

And it can be confusing. You're sitting around drinking beer, working on your motorcycle or something, you might start looking at the Newton-meter value and guess what? It's actually on your torque wrench too. You get the two screwed up and you're trying to torque something to a Newton-meter spec and it requires foot-pounds, Newton-meter's way higher. You're going to strip out the aluminum.

So pay attention, look at what you're doing. Now what I really recommend for a lot of people, three-inch ratchet. You know why? You can't get too crazy with it. You got a ratchet like this versus your three-inch ratchet, you're not going to get so much leverage on it.

You probably do yourself a favor. You know, I got friends, they work on their bike and I tell you what, they're always thinking tighter's better. And everything they touch, they go back and tighten it some more. Pretty soon you're going to stress out all those threads and you're going to be stripping stuff. And depending on what you're stripping out, it can be very costly and you don't want to do that.

So quarter-inch, there you go, you know, if you're in the quarter-20 screws, you probably just want to stick with this. They got nice little offsets. When you're torquing something with little elbow like this, it's going to change the lever ratio on it. So they always want you to torque it at 90 degrees so you don't get a bogus reading. I mean, you know, you don't want to be, you know, have it on there and amplifying the torque.

So you get a cute little crow's foot like that too. Same thing, 90 degrees. So anyway, I hope this kind of sheds a little light on torque wrenches. And like I said, when in doubt, you know, don't go with the big torque wrench on it and try and keep it in that happy zone. And it'll really save you a lot of headaches and save you a lot of money too.

So wrench safe.