3/8" torque wrench for auto repair

[hover]

I know many's position on HF tools, and am not endorsing, but:

http://www.harborfreight.com/3-8-eig...rench-807.html

No adapter necessary.

[jamestown94west]

I've got a Pittsburgh torque wrench. I've had it for years, torqued many a head bolt and many a lug nut with it. I had it sent off to be calibrated (shop paid for everyone's torque wrenches to be sent in), and after years of use it was dead on. We had a really big Pittsburgh 1" drive torque wrench as well, and it was fine too.

[Unprofessional]

I don't see any way a regular drive adapter could effect the calibration of a torque wrench as long as the centerline of the adapter aligns with the centerline of the torque wrench drive. If that's not the case, then the adapter is defective. It's all about the moment arm. The moment arm is the length from the centerline of the torque wrench drive to the centerline of the handle pin on the beam-style wrenches. As long as centerline bolt = centerline drive socket = centerline adapter socket = centerline torque wrench drive, you're golden. A moment (or torque) is equal to the moment arm length times the force applied at the handle. That's why its important that the moment arm be true in the plane but an adapter isn't going to affect that as long as the moment arm/handle is kept in the plane.

[bloobass]

An adpator won't effect calibration, it will effect accuracy. The adaptor can allow torsional twist, which will give a false reading. Granted not all adaptors, but a lower grade one made of cheaper steel would twist plenty (depending on how much torque obviously).

[68Goldfish]

If I was you I'd probably look through craigslist and try to find a better quality used one for a good price. That would be plenty fine for the work your doing. Sometimes you can rent that kind of equipment from your local tool rental outfit.

[steamthief]

Originally Posted by hover

I know many's position on HF tools, and am not endorsing, but:

http://www.harborfreight.com/3-8-eig...rench-807.html


No adapter necessary.

Seriouly considered it, but it tops out at 80, which is the exact setting needed for my lug nuts. One reviewer said it maxes out at 75, which isn't good enough, and from the reading I've done it seems that torque wrenches in general perform best in the middle of their ranges. Is that FUD?

OT, awesome sig, hover!

[Mike N]

Originally Posted by steamthief

Seriouly considered it, but it tops out at 80, which is the exact setting needed for my lug nuts. One reviewer said it maxes out at 75, which isn't good enough, and from the reading I've done it seems that torque wrenches in general perform best in the middle of their ranges. Is that FUD?

I wouldn't use a 3/8" drive anything for lug nuts.

[Biggbass]

I have a Craftsman that's at least 25 yrs old and still rockin'. It's a great tool.

[Reprise]

I use a torque wrench for my car as well, even for oil / fluid changes (yes, I'm that anal)

Some thoughts and learnings...
- As noted, that Craftsman torque wrench is made in the same place as the HF one, comes with no case, and has a 1yr warranty. The HF ones come with a case and lifetime warranty (in a HF store, 'lifetime warranty' means you take it in, show them the 'lifetime' statement on the packaging, and they give you a new one from stock.) No sending in the unit and waiting for the slow boat from... you get the idea.
(as an aside, I had a pricey floor jack I purchased from Sears that broke the 3rd time I used it - no warranty help from them (and yes, made in China). If it's not a hand tool w/ the lifetime warranty, I don't buy Craftsman any longer). Had a Craftsman clicker-type TW; took it back (I still have their beam-style; that's not a bad tool).

- If I want to step up in quality, I'll consider SnapOn or MAC (but they're real spendy for someone who doesn't make his living with them). Lowe's and HD also offer 'lifetime' warranties on their house lines, and I think one of them is actually made in the US (don't know if either sell a torque wrench).

- (to the OP): The only thing you really need a TW for on a brake job is your lug nuts when you're done. Oh, and 80 ft/lb on those for a Honda...90 or so if you've got an S2K or NSX and taking it around a track (I've owned Hondas a long time now).
- On lug nuts & dealers... be very cautious with them. They love to use impact guns (time saved is $ earned), and tighten them way past 80 ft/lb. Guess what happens when you do? Your front rotors will warp (and you'll be coming back in to spend more money with them). 'Torque sticks'? "oh, sure, we use those". Check your wheels when you get home any time the dealer removes a tire.

-You want the 1/2" TW for lug nuts. Using a TW at 100% of its rated capacity is bad, because the accuracy factor is really in the middle range of the wrench - using a 1/2" to tighten something to 8 ft/lb, for example, is as bad as using a 3/8" to tighten lug nuts to 80. Get both 3/8 and 1/2" wrenches, if you want to be serious and do it right.

- As stated earlier, always release the tension on your TW before you store it, for the reasons mentioned. Store it in its case, too. You don't have to 'baby' it, but don't toss them around, either. An occasional drop from 'fender' height isn't going to suddenly send it out of calibration (but will take its toll if continually done).

- Also as stated earlier...do not use adapters. The torque will not be accurate (same for impact sockets, if you ever get into air tools). Get the other wrench, as I mentioned above.

- DO NOT use it as a breaker bar (example: If you go to change your auto tranny fluid on that 8th gen Accord, you'll see the bolt is actually made for a 3/8" drive extension. Don't put that TW in there and beat on it with a hammer, etc. Don't even use a ratchet wrench for that. Get a genuine breaker bar for that (Sears does sell a nice 3/8" that you can use a rubber mallet on to loosen that bolt, and you'll note that anytime you are removing a fastener like that for the first time on a Honda (and prolly most mass-produced cars), that it will be on there a lot tighter than the shop manual calls for when you tighten it again.

-Don't use your TW to loosen bolts (unless you just tightened it with the TW). Personally, I'd not use a beam-type to loosen at all, but I suppose that would be OK.

Am I a professional mechanic? No. But I do do my research on tools, because I don't want to have to buy them twice, hurt myself or others, etc. Hopefully this helps those who want to do their own maintenance, either to save some $, or maybe just to take pride in a job that you know was well done (no offence to any professional mechanics that hang here - you earn every penny you get!)

[steamthief]

Originally Posted by Reprise

I use a torque wrench for my car as well, even for oil / fluid changes (yes, I'm that anal)

Some thoughts and learnings...
- As noted, that Craftsman torque wrench is made in the same place as the HF one, comes with no case, and has a 1yr warranty. The HF ones come with a case and lifetime warranty (in a HF store, 'lifetime warranty' means you take it in, show them the 'lifetime' statement on the packaging, and they give you a new one from stock.) No sending in the unit and waiting for the slow boat from... you get the idea.
(as an aside, I had a pricey floor jack I purchased from Sears that broke the 3rd time I used it - no warranty help from them (and yes, made in China). If it's not a hand tool w/ the lifetime warranty, I don't buy Craftsman any longer). Had a Craftsman clicker-type TW; took it back (I still have their beam-style; that's not a bad tool).

- If I want to step up in quality, I'll consider SnapOn or MAC (but they're real spendy for someone who doesn't make his living with them). Lowe's and HD also offer 'lifetime' warranties on their house lines, and I think one of them is actually made in the US (don't know if either sell a torque wrench).

- (to the OP): The only thing you really need a TW for on a brake job is your lug nuts when you're done. Oh, and 80 ft/lb on those for a Honda...90 or so if you've got an S2K or NSX and taking it around a track (I've owned Hondas a long time now).
- On lug nuts & dealers... be very cautious with them. They love to use impact guns (time saved is $ earned), and tighten them way past 80 ft/lb. Guess what happens when you do? Your front rotors will warp (and you'll be coming back in to spend more money with them). 'Torque sticks'? "oh, sure, we use those". Check your wheels when you get home any time the dealer removes a tire.

-You want the 1/2" TW for lug nuts. Using a TW at 100% of its rated capacity is bad, because the accuracy factor is really in the middle range of the wrench - using a 1/2" to tighten something to 8 ft/lb, for example, is as bad as using a 3/8" to tighten lug nuts to 80. Get both 3/8 and 1/2" wrenches, if you want to be serious and do it right.

- As stated earlier, always release the tension on your TW before you store it, for the reasons mentioned. Store it in its case, too. You don't have to 'baby' it, but don't toss them around, either. An occasional drop from 'fender' height isn't going to suddenly send it out of calibration (but will take its toll if continually done).

- Also as stated earlier...do not use adapters. The torque will not be accurate (same for impact sockets, if you ever get into air tools). Get the other wrench, as I mentioned above.

- DO NOT use it as a breaker bar (example: If you go to change your auto tranny fluid on that 8th gen Accord, you'll see the bolt is actually made for a 3/8" drive extension. Don't put that TW in there and beat on it with a hammer, etc. Don't even use a ratchet wrench for that. Get a genuine breaker bar for that (Sears does sell a nice 3/8" that you can use a rubber mallet on to loosen that bolt, and you'll note that anytime you are removing a fastener like that for the first time on a Honda (and prolly most mass-produced cars), that it will be on there a lot tighter than the shop manual calls for when you tighten it again.

-Don't use your TW to loosen bolts (unless you just tightened it with the TW). Personally, I'd not use a beam-type to loosen at all, but I suppose that would be OK.

Am I a professional mechanic? No. But I do do my research on tools, because I don't want to have to buy them twice, hurt myself or others, etc. Hopefully this helps those who want to do their own maintenance, either to save some $, or maybe just to take pride in a job that you know was well done (no offence to any professional mechanics that hang here - you earn every penny you get!)

I think you just sold me on the HF $9.99 1/2" torque wrench to use specifically for my lug nuts.

And a week after violently slamming my knuckles into the chassis while removing the ATF drain plug with a DIY ratchet/pipe combo, I think I'll get a 3/8" breaker bar while I'm at it!

[Floyd Eye]

$10 torque wrench? lol Screw that.

[jamestown94west]

If its accurate and you treat it with respect, there's no harm in it. Especially if its just for DIY use.

[1958Bassman]

Originally Posted by Unprofessional

I don't see any way a regular drive adapter could effect the calibration of a torque wrench as long as the centerline of the adapter aligns with the centerline of the torque wrench drive. If that's not the case, then the adapter is defective. It's all about the moment arm. The moment arm is the length from the centerline of the torque wrench drive to the centerline of the handle pin on the beam-style wrenches. As long as centerline bolt = centerline drive socket = centerline adapter socket = centerline torque wrench drive, you're golden. A moment (or torque) is equal to the moment arm length times the force applied at the handle. That's why its important that the moment arm be true in the plane but an adapter isn't going to affect that as long as the moment arm/handle is kept in the plane.

Adapters aren't absolutely rigid and if you look at it when you apply torque, you'll see that it twists. This reduces the torque that's applied to the fastener.How much depends on the material and the length of the adapter. Doesn't matter if the adapter is plated (not made for impact wrench use) or made for impact wrench use, they're still somewhat elastic.

[1958Bassman]

Originally Posted by steamthief

Seriouly considered it, but it tops out at 80, which is the exact setting needed for my lug nuts. One reviewer said it maxes out at 75, which isn't good enough, and from the reading I've done it seems that torque wrenches in general perform best in the middle of their ranges. Is that FUD?

OT, awesome sig, hover!

I wouldn't recommend trusting a wrench that's being used for it's max rated torque, especially for lug nuts and head bolts. Mid-range use is good- I know they have a 1/2" drive torque wrench- use a 1/2"-3/8" adapter and you'll be fine. An extension isn't a good idea, for the reasons I mentioned in my last post.

Lug nuts come off all the time and you should find out if they're supposed to be installed dry, or if it's OK to use anti-sieze compound. It makes a difference of 10-20%. I was the service department for two different boat dealers and am a regular on a ski boat forum- someone posted within the last few days about leaving for a trip with the boat and after a few miles, watched the left wheel rolling across the freeway as the trailer scraped along on the rotor or drum. Aluminum wheels can be deformed by uneven/excessive torque and that's a major problem at freeway speeds, as you know.

[Downunderwonder]

Originally Posted by bloobass

An adpator won't effect calibration, it will effect accuracy. The adaptor can allow torsional twist, which will give a false reading. Granted not all adaptors, but a lower grade one made of cheaper steel would twist plenty (depending on how much torque obviously).

Unless there is a midget hiding in your engine bay grabbing the adaptor there is no way for the torque of the wrench to be any different to the torque on the fastener. You could put a 10ft long mild steel extender on and it would transfer the same torque. Just bring up the torque without bouncing.

[Mike N]

Originally Posted by Downunderwonder

Unless there is a midget hiding in your engine bay grabbing the adaptor there is no way for the torque of the wrench to be any different to the torque on the fastener. You could put a 10ft long mild steel extender on and it would transfer the same torque. Just bring up the torque without bouncing.

Extensions suck up torque. I sure as heck wouldn't use one on a torque wrench.

[68Goldfish]

I agree, I don't generaly use an extension with a torque wrench unless I absolutely have to. That said, I think the OP is just talking about a 3/8 to 1/2 adapter which is so short and stout that I can't see it affecting anything.

[Unprofessional]

Right. Adapters and extensions are two totally different animals. I thought we were talking about adapters.

[Mike N]

Originally Posted by Unprofessional

I thought we were talking about adapters.

We were, until Downunderwonder mentioned putting a 10 foot extender on and it not affecting torque.

Adapters I have no real issue with, especially going from 3/8" to 1/2". Going upwards is ok, downwards I'm not so sure.

[AnchorHoy]

Originally Posted by 68Goldfish

I don't generaly use an extension with a torque wrench unless I absolutely have to. That said, I think the OP is just talking about a 3/8 to 1/2 adapter which is so short and stout that I can't see it affecting anything.

Agree

I can't see how a 1/2 to 3/8 adapter could possibly flex enough to affect accuracy in any meaningful way. They're barely an inch long....

For The Record, all three of my torque wrenches are Snap-On clickers but I have no problem with Craftsman. Personally, I wouldn't use a Harbor Freight tool if you gave it to me. YMMV