Mechanics Using Cordless Drivers - Over Torque?
 

Hey Friends - I've noticed over the past few years with the price of cordless drivers dropping and how much time they do save, that more and more mechanics are using them versus the traditional 3/8" ratchet and sockets.

I actually recently challenged a mechanic on this and asked "how do you know that you're not over torqueing the bolt??" to which I never received a straight answer. Its not like you can pre-set a torque value on these electric drivers and I know several of these brands have very powerful motors...so certainly made me wonder.

I am from the traditional school of repair:
1) Remove fastener
2) Chase threads on fastener AND recipient hole
3) Blow out debris with compressed air
4) Light lube on threads or anti-seize (based on application)
5) Run up fastener by hand
6) Torque to spec

I just don't see this being done anymore esp. with the advent of the cordless drivers.

Thoughts?

I use them to take off nuts and bolts... sometimes to put back on, but not tight, then torque them by hand

^^^ This. Mine has a low setting that does little more than snug a fastener.

If my driver fits in the space I'm working in, I'll probably use it - and save a ton of time in the process.

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We have been over tightening bolts with air tools for a hundred years, the cordless stuff only makes it more convenienthttp://forums.pelicanparts.com/support/smileys/wat3.gif

LOL.

Or not so LOL when I'm trying to undo what has been done by someone else's power tool. Replacing a snapped off wheel stud? Check. Lug nut tightened to 400 ft-lbs? Check.

Torque output drops with charge level. No way I would trust a cordless to get anything tight, especially if it's been used a few times since charge and you're tightening lugs.

I would never trust a cordless tool to give me the final torque on a bolt. Never.

I had a flat while driving my wife's car. I could not get the lug nuts off with the cheap stamped metal tube lug wrench provided with the car. The wrench would just cam off the nuts. Don't know what the nuts were tightened with at the dealer when she bought new tires but sounds like it could have been a cordless driver. Had to call a tow truck. He had a proper wrench at least.

my 18v fuel milwalkee will CERTAINLY over torque just about everything.

I had a tire replaced in September, when I went to put my snow tires on the nuts would not come off with my 300 ft-lb impact gun. Typical garage gorilla. If I was roadside with a flat I would have been effed.

After getting wheels put on at a shop, I always break the nuts loose and torque myself.
Lot easier to do in my shop than on the side of the road.

Exactly. I borrowed my parents' Infiniti a couple years ago, and thought I'd do an oil change in my driveway while I had it. The car's always been dealer maintained, even to change a flat they had several months earlier. I could not get the lug nuts off with any hand tool. And I couldn't find the lug wrench stored with the spare tire, either. Musta been accidentally pilfered/lost when AAA/dealership did the work. I finally resorted to slipping a spare floorjack's 4-foot long handle as a breaker bar over another OEM lug wrench I had laying around. I had to bounce on top of the bar to get the lug nuts off. Kinda bent the lug wrench into a banana shape while I was at it.

Whats worse is that I've had 2 different oil pan bolts done dirty by the same shop-which was 300 mi away by the time I discovered. I got both out, but they were mutilated and ruined my day.

After all tire changes I loosen the lug nuts, and then torque them on the El Camino. I have had new tires mounted with lugs at stupidly over torqued and some that were just slightly snug or loose.

For the 911, I always remove the wheels, throw them in the back of the Elky, and deliver them to a local Porsche mechanic shop with the proper wheel matching and a road-force balancer, and most important of all, the operator that cares.

I use it to just snug it down, then i always do the final tightening by hand.


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I just bought a few impact wrenches because of the impact wrench thread. I'll post pics of them there.

I've settled on a practice that is the opposite of what I'm seeing you guys do:

Break the lugs free by hand. Use the speed of the impact to loosen the bolts and to re-tighten. Final tighten with a hand torque wrench set at 98lbs.

Why? Because the electric impact wrench is so strong, it'll rip the threads right up if you zip the bolts off all the way from tight. The bolt is hot to the touch. You see little metallic glitter pieces in the lug bolt hole and on the lug bolt threads.

I've always done the same - one time broke the 3/8ths end clean off a breaker bar trying to loosen the way over torqued lugs. I asked the manager to explain why he feels it is necessary to tighten so much. He said he wanted to make sure he had no complaints about wheels falling off on the highway after leaving his tire shop.

On another thread I had mentioned that I purchased my 2013 BMW 128i - Certified Pre Owned and dealer maintained and did the first oil change under my care. The engine under tray has 15 fasteners to remove. About half of the female (plastic) nuts were stripped. I assumed from techs using electric drivers with no regard to the proper torque.

I worked at a porsche shop for a while but I wasn't a tech. When I asked the guys about torquing bolts, they said they make them tight and that's good enough. From what I understand, that's SOP at a lot of places. Might not be right but it's real world experience.

I think that's normal practice for most people, aside from engine building and lug nuts I do not use a torque wrench.

Even Project Binky makes do with 'three ooga-doogas' when it needs to be tight.

Getting upset at mechanics for using power tools to tighten fasteners , is like getting upset at your excavator for not hand digging your footer