When to use an impact wrench...?

[hattitude]

I recently used my impact gun to remove my belt drive pulley. It had never been removed since assembled at the factory. It took my gun some effort to get the bolts off. They were caked with red locktite... It would have been a pain in the butt to remove them all without the gun, even with my breaker bar...

I started to think,  I read a lot of people mention using breaker bars when removing some of the harder to move bolts. I can't remember that last time I read about the use of an impact gun on this forum. A lot of you work in the industry... so I have to ask....

Do most people mention breaker bars because they don't have access to air tools?

Are there certain nuts/bolts that should never see an impact gun for removal? Is there a general rule to follow on when to use or not use an impact gun?

Brake rotors, drive belt pulley, compensator, clutch basket, axle, etc......?

Thanks for the benefit of your experience.....

[jrgreene1968]

I spin wrenches for a living on heavy equipment, have every size impact you can buy, but I don't use an impact nowhere on my bike.

[PoorUB]

I use an impact fairly often, just for the time it saves removing bots by hand. I have a 3/8" butterfly impact that gets used to remove primary cover, and similar bolts.

I tried to rattle off the pulley nut on my '05, gave up and drilled it with two 1/4" holes opposite each other and broke it off, and replaced it. I know guys do it all the time, but using an impact on the tranny or the engine crankshaft makes a bit nervous.

[hattitude]

Thanks for sharing your opinions/experience.......

[jbexeter]

Heavy / marine engineering background here.

Typically an impact was only used to remove studs, not nuts, and certain grades of studs, eg wheel studs on wagons...

Even on a stuck flange you'd put the impact on the bolt side and a spanner to lock on the nut side, not the other way around.

Impacts traditionally had piss poor torque regulation, and you could get 1" drive jobs that would hit the high side of 2,500 ft/lb, so we did not mind using them on stuff where you threw the entire fastener away after it was removed...

Speaking entirely personally I can see an automotive use on wheel studs, I cannot see any other automotive use or any motorcycle use.

Same goes for the hit it with a hammer type of impact wrench.

I do find an air ratchet spanner to be a useful tool, but they are a different thing entirely.

For every time I used an air impact there must be 500 times I used oxy heat / quench and rapping with a brass bar on a stuck fastener.

Did once see a guy shatter a unit construction motorcycle engine casing with an air impact, he was trying to undo an engine sprocket and did not realise it was left hand thread, full tank pressure and let it run for 30 seconds, suddendly had oil running on the shop floor... .;*)

[harley_cruiser]

Red locktite = heat.
Very seldom use impact. Never on the compensator nut because of the magnets in the rotor, although I know a lot of guys do.

[hattitude]

Good info... thanks all...

I kind of suspected what responses I might get, so I'm not surprised...

It certainly won't kill me to put away the impact gun, unless I'm rotating the tires on my cars/truck......

I know I have a big cheater bar somewhere....

[masstch]

Ill use an impact on lots of things that aren't particularly tight, just to
Save take down time. Example: primary cover, trans door, derby; I have a 1/4" drive impact that makes short work of this type of stuff. I do use a big impact to remove the belt sprocket, but what's really important is paying heed to where that energy is going. I back up the sprocket such that the blows are absorbed by whatever tool or holder is securing the sprocket. I never let it bang against the trans gears. I don't use an impact to *tighten* stuff on the bike, only to run up the threads of some long-winded screws, then hand tools to finish.

[jbexeter]

with respect, that is what an air ratchet is intended for.

I'm wondering are people confusing air ratchets and air impact guns?

[jmorton10]

with respect, that is what an air ratchet is intended for.

I'm wondering are people confusing air ratchets and air impact guns?

Air ratchet are just what they sound like. They work just like a regular ratchet (usually 3/8 drive although I have a 1/4" one also) until you appl air & then they spin on their own.

Impact guns are what you spin wheel lugs etc. off with.  I have them in 1/2" and 3/4" drive.  They are far more powerful than an air ratchet.

Although everyone here will say its wrong, I have spun off hundreds of compensator nuts for years with a 1/2"  impact and it has never caused a problem yet.

Also, I have wrenched in two official Harley shops at times & the guys in those shops did that also.

~John

[smokedyvr]

  I have to agree, seen many use and personally use and impact to REMOVE comp nut but that's it......clutch gets a breaker bar. Everything going on gets hand started, ratchet snugged and torque wrenched tight. I also have a air ratchet but seldom use it on the bikes. Seems to get more use on the Superduty!

[PoorUB]

with respect, that is what an air ratchet is intended for.

I'm wondering are people confusing air ratchets and air impact guns?

I have a couple air ratchets too, but my little butterfly impact works faster.

[Bikerscum]

One of the biggest mistakes people make with an impact gun is not using an impact socket. The special sockets aren't just stronger, they're heavier... more mass smacking at the nut/bolt to loosen it.

[a_disalvo]

If you "pull" on the socket away from the impact gun as you are using it you will reduce or eliminate the inpacts and have a high torque wrench. I've used this method on compensator nuts and never have a stater or rotor failure. Regards, Frank

[Jacob1955]

I think its safe to say the Factory uses Air wrenches

[Admiral Akbar]

I think its safe to say the Factory uses Air wrenches

I don't think so... I expect that they use specialized torque drivers..

[88b]

I think its safe to say the Factory uses Air wrenches

I don't think so... I expect that they use specialized torque drivers..

Exactly air driven torque drivers.
I use air wrenches all the time working on cars and a few bits on bikes. Save a lot of RSI on the body 

[masstch]

with respect, that is what an air ratchet is intended for.
I'm wondering are people confusing air ratchets and air impact guns?

I couldn't DISagree more. Air ratchets (I didn't confuse the terms) are a fall-back for those long-winded fasteners that can't be easily accessed with an impact wrench. If it weren't for close-quarters use, air ratchets wouldn't exist.
Air ratchets are WAYYYY slow compared to any impact, RPM-wise. I have a drawer full of both in all the sizes and I *rarely* use the air ratchets. The little 1/4" impact that is use for assembly isn't going to over-torque anything with a 1/4-20 thread or bigger, even IF you let it hammer for a while, which I never do. I use it only for quick take-down and assembly run-up, followed by the proper hand tools to snug or torque as needed.

[jbexeter]

THAT is what I use a old cordless drill with knackered battery for with the chuck set to literally "Potty mouth"k all torque before slippage.

I had it explained to me in a beautiful manner.

The pitch of the threads convert even minute amounts of torque into very significant forces, so you take a long door hinge and modify the end of it (he actually had one already made as a teaching tool) and the other end is 6 mm threaded rod, with a captive nut on one hinge end and the end of the rod fixed in a small bearing at the other hinge end, so spinning the threaded rod opened and closed the hinge.

he said if you think you can control it or it's nothing torque wise and unable to do any damage or any other reason you have, put your cock in it,  and use the tool of your choice to do it up just tight enough to it grabs your cock and doesn't fall off.

I said I'd rather use a spanner and do it by hand, while using it to grip my thumb and turning the threaded rodf by hand.

Funny that he said, 30 years as a chief engineer and hundreds of guys studied under him, and they all had exactly the same response as you

NOT telling anyone else how to do it, your tools, your shop, your business, not for me though.

[Ohio HD]

I think its safe to say the Factory uses Air wrenches

I don't think so... I expect that they use specialized torque drivers..

         http://www.ingersollrandproducts.com/tools/fastening/catalogs/QA4%206%208%20Series%20Brochure.pdf

[wholehog]

if a breaker bar won't do it use some heat on the loctite and a persuader pipe

[masstch]

 http://www.ingersollrandproducts.com/tools/fastening/catalogs/QA4%206%208%20Series%20Brochure.pdf


Without question, the MoCo and other production facilities use very specialized (expensive) purpose-built air (and electric) tools. Wouldn't it be awesome to have a box full of them? I'd have to get a whole 'nuther KRA box.
There's a MoCo video showing engine assembly and they have the cutest air powered 'box end ratchet wrench' just for rocker boxes(!)
Now, back to the *real* world: Real tools that real people have. Most of us have air ratchets and various impacts. I would suggest everyone use the tools they are comfy with. If you are breaking or stripping things, maybe you should rethink. I'm quite comfortable running primary cover screws with air help. Also, it's true, that there is a *published* torque value for EVERY fastener. If you are spending the extra time to actually *torque* every little fastener, well, good on ya. I've been wrenching on and off for nearly fifty years, I'm convinced that I can safely install certain non-critical fasteners correctly just by using feel and experience.

[FlaHeatWave]

Yep, the calibrated wrist and the educated elbow...

[1FSTRK]

Time-sert and Heli-coil thank the true believers.

[PoorUB]

When I had my small engine shop I would in in 5/16" head bolts with my 3/8" impact. I would turn the air down, and got pretty good at dropping the trigger about the time the impact hammered once or twice. With the low setting the bolt would get maybe 5 ft-lbs and I was torquing to 17, so it worked out well.

On my HD there is not very many bolts that I feel safe running them in with the impact. I use an air ratchet once in a while, but it is not much faster that spinning a "T" handle on small screws  like the primary or cam cover. I might run them out with a impact, but go back to hand tools on assembly.