Cordless impact guns - achieving correct torque?

[Rgm racer]

Could some of you track day drivers/racers that have good experience of impact guns please answer the following.

I see any decent gun will achieve way more than the required ft/lbs or nm of torque to do the wheel nuts up, so does the tool automatically stop/slip once the nuts are tight enough as otherwise surely it will just strip or even shear the thread? And is it then just a case of checking/torquing tight with a wrench to double check tight?

[Wh00sher]

My impact gun always leaves the wheelnuts requiring tightening to the correct torque afterwards.

You`ll struggle to find one that`s powerful enough to strip the threads.

[Mr MXT]

Rgm racer said:

Could some of you track day drivers/racers that have good experience of impact guns please answer the following.

I see any decent gun will achieve way more than the required ft/lbs or nm of torque to do the wheel nuts up, so does the tool automatically stop/slip once the nuts are tight enough as otherwise surely it will just strip or even shear the thread? And is it then just a case of checking/torquing tight with a wrench to double check tight?

I was taught you weren't supposed to use impact wrenches to tighten nuts up for this very reason.

Suitable for removal only.

[weed]

The cordless impact wrenches are good for running the wheel nut/bolts snug to the wheel or for running off fasteners that have had the tightening torque broken. the quality cordless wrenches can break the torque of the fasteners.
Typically, a torque wrench is used to torque the nuts up to the car or wheel manufacturers spec.

The pneumatic driven impact wrenches are what over torque the fasteners and can warp rotors and hubs.

m

[b16a2_VTi]

I use a Clarke one, brought from machine mart for £90 (think they are about £105 now).
Had mine for a few years now, served me well.

I use them to take the nuts off, i do use it to put nuts on, but not tightening them up too much as i use a touque to ensure they are correctly torqued up.

Saves me alot of time!!

[Ricey155]

More of a time saver than anything else for me, still use the breaker bar to undo and tighten

best to be safe

[chormy]

Breaker to loosen and do up wheel nuts , rusty nasty nuts impact wrench

[HughesR1]

When racing we do it just until the wheel is flush on the hub, or the gun begins to slip. Then we torque with a torque wrench.

Purely depends on how much battery power is in our gun, but never rely on the gun to torque the wheels.

[mrmr96]

Use a torque limiting socket (or extension). This stops the wheel gun, and leaves the torque of the nut lower than you want, so you can finish them off with a proper torque wrench.



I've been doing this with no problems for a number of years on my track car. Obs it's very important to make sure that the nut is not cross threaded before you start. Cheers

[GC8]

They arent a combined work tool and measuring tool, so you cant preset the required wheel nut torque. Each time they strike they apply force. The only way to limit the torque is to limit the number of strikes. As mentioned above, you can buy tools which limit the torque making it easier if you are concerned about over tightening.

[philevo6]

Wh00sher said:

My impact gun always leaves the wheelnuts requiring tightening to the correct torque afterwards.

You`ll struggle to find one that`s powerful enough to strip the threads.

I disagree....my snap on 18v gun will remove ANY nut and strip/snap any thread if held on too long.

Its a beast!

I always nip them up with the gun then torque up properly.