Repair-It

I am trying to be a little more professional with my repairs. I am realizing very quickly that I need more tools.

I have some projects coming up that require low torque specs:
Spark plugs on the Mazda3 - 8-10 lb-ft (based on forums)
Spark Plugs on the Corolla - 21 ft-lbs based on actual plug box
Valve cover gasket on the Corolla - Torque spec for the outer perimeter bolts/nuts is 8 ft. lbs., Torque spec for the inner bolts near the coils is 80 inch. lbs.

So I was looking at this:
http://www.sears.com/craftsman-micro-cl ... ockType=G3

it is good for 10 - 75 lb-ft.

My low end is either right at this, or just below. How much of an exact science is this? Can I get away with 10 as the low setting? Do I really need 2 wrenches, then a third for more than 75 lb-ft.?
What do you guys recommend?

I've gotten away with a single 1/2" torque wrench that starts at 20 lb-ft. I don't think I have torqued spark plugs before.

I like to torque:
Lug nuts
Suspension components

I don't even torque brake components, now that I think of it.

What are the torque specs for Lugs and suspension components? More than 75? My father in law has an inch - lb. I could borrow for the lower stuff. I think that would go to 20.83 ft-lbs. (250 inch-lbs., at least that is the Craftsman spec, not sure which one he has.)

The only thing that is more Corolla spark plugs at 21. Sounds like that would do it.

Lug nuts are almost always universally 100 lb-ft but I've seen a bit lower and obviously trucks can be a lot higher.

Suspension can vary. On B-bodies, 35 lb-ft is common for something in the steering linkage (like pitman arm to center link or something). But larger bolts can be a lot more, like control arm mounting nuts.

Fun fact: my 93 Caprice GM service manual lists different torque specs depending on if you are measuring at the head of the BOLT, or at the NUT. More friction at the bolt when turning so it gets a higher torque value even though the actual fastener clamping force should be equivalent.

So the 10 - 75 doesn't really make sense. doesn't go low enough for what I am doing now, and doesn't go high enough for later stuff. I will check the specs on my father in law's in-lb., or potentially just buy my own.

Yep, in-lb torque wrenches have gotten me in more trouble than they have helped. Spark plugs seem like a candidate for this, but if the thing doesn't click, you can easily get in trouble. Might be best to just have an experienced helper for the first time to guide you on how hard to torque them.

100 lb-ft for all wheel lugs.. that's my move! Definitely go for something that can handle 100 lb ft, and don't cheap out on the torque wrenches. You want them to click when they're supposed to.

I've seen up to 160 lb ft for things like suspension bolts and crank pulleys..

Pinion nuts for rear differentials can be like 250 lb-ft.

One of the big box home stores may sell a longer 1/2" torque wrench that goes to 250, but it probably doesn't start at 20. 20-150 is probably the first DIY torque wrench you should buy, before any other range.

Thanks guys. This is really good feedback. I may wait on it then since I don't need to do anything in the 20 to 150 range right now.