I'm working on a 440 motor (installing timing chain) and I don't have a torque wrench (for damper bolt and timing chain cover bolts etc) . (Actually I'm wondering how important a torque wrench is as opposed to tightening by feel). Anyway if I did buy ONE what is the best size torque wrench to buy? I'm talking about drive size (3/8", 1/2" etc) and torque range ( that is range of ft lbs the wrench should cover)? Best brand is nice but optional. Thanks Paul
what is best size torque wrench to buy
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What's the torque specs of the fasteners you want to torque? That will tell you what wrench you need. To do it right, you may need 2.
I think the torque of the damper bolt is 135 ft/lbs. I don't know about the timing cover bolts or other bolts I took off (compressor, alternator, etc). Paul
The small bolts like the cover bolts are low torque ft/lb. The factory service manual may not have the specs in in/lb which is what mose small fasteners are torqued to now days. I torque rod and main caps and head bolts. Everything else is with a wrench or ratchet using common sense. There is a reason why 1/4" ratchets are usually only 5" long. Catch my drift? A 150 ft/lb wrench would work fine for the larger fasteners in an engine.
There is a difference between tightening to "feel" and tightening to a torque spec. If you have a spec, it should be followed.
I recommend a good wrench with a 1/2" end. You can use an adaptor for smaller sockets. They usually range from 25 to 150 pounds. Sometimes torque ranged are in inch pounds; for that you would need a different, smaller wrench.
I don't recommend the bar type, even though some insist they are more accurate.
Unless you are buying one of the high range wrenches that sell for around $300, always "unload" your wrench when you are finished with it.
Here is one I have had:
https://www.amazon.com/CRAFTSMAN-To...hvlocphy=&hvtargid=pla-4583795267692939&psc=1
Here is one I bought after the plastic adjuster on the Craftsman broke:
https://www.summitracing.com/parts/sum-907067
I recommend a good wrench with a 1/2" end. You can use an adaptor for smaller sockets. They usually range from 25 to 150 pounds. Sometimes torque ranged are in inch pounds; for that you would need a different, smaller wrench.
I don't recommend the bar type, even though some insist they are more accurate.
Unless you are buying one of the high range wrenches that sell for around $300, always "unload" your wrench when you are finished with it.
Here is one I have had:
https://www.amazon.com/CRAFTSMAN-To...hvlocphy=&hvtargid=pla-4583795267692939&psc=1
Here is one I bought after the plastic adjuster on the Craftsman broke:
https://www.summitracing.com/parts/sum-907067
I wouldn't use one for what you are doing.
Next... I used to be partners in a A2LA accredited calibration lab. We quite literally calibrated thousands of torque wrenches and I personally have done hundreds of them. Here's what I can tell you about torque wrenches... We also did a ton of other stuff, but I digress...
First, the big names "Snap-On" etc. aren't much, if any better than the cheap Harbor Fright ones. In fact, there was a run on some real crap from Snap-On for a while (Had the guys at the nuc plant going crazy) and they were off right out of the box.
The most accurate for home use is a bending bar type. I personally like these. 2% accuracy . There are dial types that are as, or more accurate, but the bending bar type is much more robust.
The ones most used are the clicker types. 4% clockwise and 6% counterclockwise accuracy over the upper 80% of the range was typical. A lot handier to use, but not as accurate and you have to remember to set them to a low value for storage.
So... The one to buy is actually two if you want to torque everything... One would be a 1/2 drive with maybe a 20-150 lb/ft range and another would be a 1/4 drive 20-200 lb/in. Note lb/in versus lb/ft.
But again, for what you are doing, I wouldn't use a torque wrench. The pros never do... I'm not a pro, but for an engine, I use a torque wrench on head bolts, main cap bolts and rod nuts.
They are more accurate and unless you bang them up or let them rust etc., they maintain that accuracy. I've calibrated hundreds and our shop calibrated thousands of torque wrenches. I can probably count on one hand the number of bending bar wrenches that we rejected for not reading within tolerance.
Samplingman
Old Man with a Hat
Damper bolt = 2 quick shots with an impact gun and done. Chain cover bolts = make a muscle. BUT I'd still have a decent torque wench in the box, you never know when you may need it. I have the clicker type and even with the accuracy problems it is still good to know every bolt is done to the same spec.
But they have to be used correctly, which is why I don't like them. Where we amateurs are involved, they are rarely so.
Rainy Day
Member
1/2" bar type. I have used it thousands of times.
Well... From what I've seen, there's a lot of people that don't know how to use a torque wrench. Some clowns use them as breaker bars!! Or put a pipe over the end... Then toss it in the toolbox with the rest of the junk.
Biggest problem with a bending bar wrench is not looking at the dial correctly. Lot's of guys don't have the strength to pull the wrench and watch the dial.
3175375
Senior Member
I have a digital craftsman. My old one that I had from the early 80’s broke. For the RV lug nuts, I borrow my cousin’s.
When I went "big time" and bought my first torque wrench in the 1980s, I looked at both types, the bending bar (which was the first type, from back in the 1960s) and the "clicker" (like everybody I knew had). I first used it on lug nuts, in a torque sequence.
They were 1/2" drive, so I bought a 1/2" to 3/8" adapter at Sears. No problem.
Later, I bought a clicker.
What I liked about the bending bar style was that you could feel the torque as you tightened the lug nuts. HAD to make sure you used a slow, steady pull. HAD to make sure you pulled at an exact 90 degree angle to the stud or bolt hole. Religiously! Or the torque could be incorrect as the pointer would drag on the scale. With the clicker (also from Sears), it was much easier and fool-proof to use. Set the torque on the handle, when it clicked, stop torqueing. Next level. Cycle repeat until the final torque waw reached.
DO remember to relieve the torque setting when the clicker is not in use. Seems like the normal one went from 15 to 120 or so? Do keep it in its carrying case when not in use, too.
On new, gasketed spark plugs, when you seat the plug in the head, then turn it another 1/4 turn, that's the recommended torque spec. Same with tapered seat plugs. When you turn the plug that extra recommended amount, that's the torque spec. in the manual. I checked that for grins one day way back then.
Used to be that the instructions which came with the torque wrench had many tips of what to do, how to do them, AND what not to do.
Enjoy!
CBODY67
They were 1/2" drive, so I bought a 1/2" to 3/8" adapter at Sears. No problem.
Later, I bought a clicker.
What I liked about the bending bar style was that you could feel the torque as you tightened the lug nuts. HAD to make sure you used a slow, steady pull. HAD to make sure you pulled at an exact 90 degree angle to the stud or bolt hole. Religiously! Or the torque could be incorrect as the pointer would drag on the scale. With the clicker (also from Sears), it was much easier and fool-proof to use. Set the torque on the handle, when it clicked, stop torqueing. Next level. Cycle repeat until the final torque waw reached.
DO remember to relieve the torque setting when the clicker is not in use. Seems like the normal one went from 15 to 120 or so? Do keep it in its carrying case when not in use, too.
On new, gasketed spark plugs, when you seat the plug in the head, then turn it another 1/4 turn, that's the recommended torque spec. Same with tapered seat plugs. When you turn the plug that extra recommended amount, that's the torque spec. in the manual. I checked that for grins one day way back then.
Used to be that the instructions which came with the torque wrench had many tips of what to do, how to do them, AND what not to do.
Enjoy!
CBODY67
ynst
Member
I still have/use the Sturdevant beam and pointer torque wrench I bought in 1963 along with a slew of newer click type wrenches.
As was mentioned earlier, calibration is important. I get mine re-calibrated periodically if I use them a lot.
Beware of torque wrenches with plastic adjustment grips. The plastic grip comes lose and you can't adjust them. I had that issue with a couple of MAC torque wrenches about 18 years ago.
Each of my three Magnums has a torque wrench in the back for changing tires every spring and winter when the snow tires get swapped on and off. I'm not a "by feel" mechanic. I've had to correct too many of those "by feel" guys mistakes over the decades.
As was mentioned earlier, calibration is important. I get mine re-calibrated periodically if I use them a lot.
Beware of torque wrenches with plastic adjustment grips. The plastic grip comes lose and you can't adjust them. I had that issue with a couple of MAC torque wrenches about 18 years ago.
Each of my three Magnums has a torque wrench in the back for changing tires every spring and winter when the snow tires get swapped on and off. I'm not a "by feel" mechanic. I've had to correct too many of those "by feel" guys mistakes over the decades.
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