Impact wrench choice for car work...size vs torque

[Conor]

So...

I have wanted one of these for a while but could never justify it (or need it, for that matter). Now that I am working on my alternator, I need something to release the nut holding the pulley - and it will be useful for track day wheel switching.

A few months back I bought a DeWALT cordless drill with 2 x 4Ah batteries, so it's a no brainer to get a similar branded wrench..

I have found these two for the same money at £159.99. One is more compact at the expense of lower torque than the other with higher torque, in a bulkier unit. Wondering what is best for a car. I am inclined to think that the compact, "weaker" unit should suffice as it may reach places the larger one can't. Considering a lot of applications for torque wrenches revolve around construction etc. Cars, in comparison are lighter duty??

1. DEWALT DCF899N-XJ 18V XR BRUSHLESS - Max torque 950Nm
   
2. DEWALT DCF894N 18V XR BRUSHLESS - Compact - Max torque 447Nm

Is the 813 Nm breakaway torque of the compact unit enough for a car? I guess it is??

Any opinions?

Thanks
Conor

 

[Tony Dyson]

I can't find any details of what the tools are rated to torque from? I think you would have more use for it at the lower end?

 

[AnthonyUK]

The 899 I saw on the Mercedes source youtube channel where it was used to remove a crank pulley bolt, the only battery powered one that could do so. It is however very bulky and may limit where you can use it.
I have just bought a Ryobi model rated at 420nm which is adequate.
It does require a high output battery to work optimally e.g 4-5aH.

 

[Rob76]

I would go for this one:
https://www.kelvinpowertools.com/dewalt-dcf887n-18v-impact-driver-naked-c-85-p-11382

200Nm should be more than enough for removing bolts from a car, much higher and it will eat through adaptors

 

[Oldspanners]

Ordinary hand tools will take off any normal fasteners so I'd go for the largest torque rating, the one mentioned on Mercedes source seems to have the highest torque at the moment to such an extent that he is now going to change over from pneumatic tools to electric.
As with all power tools access to restricted space is always a problem.

 

[ianplymouth]

.

 

[mercmancdi]

I would always buy the smallest I can with the highest tourqe ,
I thought I was great couple of yrs ago bought big powerful gun with no adjustment. Ended up it would fit very few places only wheels etc and even then had to be careful not to snap them. I then bought a smaller one less power but at least it fitted in behind the wheel to take off callipers etc and I bought a breaker bar for anything too tight for the gun, and then used the gun once the nut / stud etc moved slightly. Big is very limited as to where you can use it.

 

[Conor]

I would always buy the smallest I can with the highest tourqe ,
I thought I was great couple of yrs ago bought big powerful gun with no adjustment. Ended up it would fit very few places only wheels etc and even then had to be careful not to snap them. I then bought a smaller one less power but at least it fitted in behind the wheel to take off callipers etc and I bought a breaker bar for anything too tight for the gun, and then used the gun once the nut / stud etc moved slightly. Big is very limited as to where you can use it.

I think that is solid advice... I wanted this gun to be last word on breaking open stuff. But I guess it's no use if I can't use it anywhere.

I am going to go go and have a look at both of them now and see. The smaller one with 425 should still be ok for most bits I would imagine.

By the way.. the mammoth 900Nm unit has 3 settings.. It works for both opening and also tightening. Ken on Mercedes Source put it on low setting for wheel nuts and it would click/stop below the desired torque for the nuts, which he was mega impressed with. Just saying it's not only a brute force machine and the smaller will probably function the same.

 

[LostKiwi]

The 899 I saw on the Mercedes source youtube channel where it was used to remove a crank pulley bolt, the only battery powered one that could do so. It is however very bulky and may limit where you can use it.
I have just bought a Ryobi model rated at 420nm which is adequate.
It does require a high output battery to work optimally e.g 4-5aH.

I have the same Ryobi. Quite impressed with it to be honest.

 

[bembo449]

I have an 18v snap on at the mo but when it dies im goin with the dewalt XR with the most go in it

 

[umblecumbuz]

... Ken on Mercedes Source put it on low setting for wheel nuts and it would click/stop below the desired torque for the nuts, which he was mega impressed with. Just saying it's not only a brute force machine and the smaller will probably function the same.

Agree with this philosophy. I've watched Mercedes Source for years and have a lot of confidence in Ken's advice. An impact gun with high torque and adjustability would be my ideal. I bought a cheapie years ago (air driven) which just about fills my needs, but I would like a better one now they're getting more powerful and versatile.
I have Hitachi electric everything else, so it would have to be a Hitachi.

 

[mercmancdi]

Actually this is what I bought.
DEWALT DCF894N 18V LI-ION XR BRUSHLESS CORDLESS IMPACT WRENCH - BARE (442HP)

 

[Conor]

Agree with this philosophy. I've watched Mercedes Source for years and have a lot of confidence in Ken's advice. An impact gun with high torque and adjustability would be my ideal. I bought a cheapie years ago (air driven) which just about fills my needs, but I would like a better one now they're getting more powerful and versatile.
I have Hitachi electric everything else, so it would have to be a Hitachi.

Yes, he seems like a very grounded and reliable source.

Actually this is what I bought.
DEWALT DCF894N 18V LI-ION XR BRUSHLESS CORDLESS IMPACT WRENCH - BARE (442HP)

Me too.. I have ordered that and will collect tomorrow - I think 447 Nm will be enough.. and it even has higher breakaway torque, which I assume to be a torque that is applied as a "boost/impact" when it detects a stuck nut.

It will be smaller and should do the job.. I like the idea of the bigger one being "the last word" in handheld torque.. but I do think it will be overkill for my needs.

I have the same Ryobi. Quite impressed with it to be honest.

Yea, Ryobi are good too, my dad have some stuff from them at home and it's decent. I just got the DeWALT drill on special offer with 2 x 4.0 Ah batteries a few months ago for £150, which I jumped at.. So it makes sense to keep in the family.

I did get the Milwaukee cordless wrench though, but that seems unique and I hadn't seen similar from another brand. I won't continue with Milwaukee as I think it's a bit pricey/overkill for amateur, infrequent use.

 

[Chrishazle]

If you want to look at a load of different manufacturers tools and fancy a trip to the Kent Showground, Detling, near Maidstone, the FFX Tool Show is on in 2 weeks time, free entry/parking, loads of tool suppliers every year including DeWaly, Metabo, Hitachi etc etc etc.
https://www.ffx.co.uk/tools/toolshow https://www.ffx.co.uk/tools/toolshowexhibitors
Easy to get to - M20 J7, A249 towards Sittingbourne, get in LH lane as you go up Detling Hill and follow the queue/marshalls signs. Prices at the show are normally very good, I'd recommend going the Friday as I suspect the weekend days will be very crowded (we've been twice, both times Friday and it was OK).

 

[Frontstep]

I bought a Milwaukee jigsaw recently and was impressed, never had their stuff before it is chunky stuff though.

Saying that I bought a Bosch Pro laser and that's very good a bright green self levelling thing.

On the other hand I keep saying I will do less but keep buying stuff ?

I have a biggish extension job I will avoid contact with, well I will try and convince myself I will anyway.

Perhaps I need a hobby ?

 

[Conor]

If you want to look at a load of different manufacturers tools and fancy a trip to the Kent Showground, Detling, near Maidstone, the FFX Tool Show is on in 2 weeks time, free entry/parking, loads of tool suppliers every year including DeWaly, Metabo, Hitachi etc etc etc.
https://www.ffx.co.uk/tools/toolshow https://www.ffx.co.uk/tools/toolshowexhibitors
Easy to get to - M20 J7, A249 towards Sittingbourne, get in LH lane as you go up Detling Hill and follow the queue/marshalls signs. Prices at the show are normally very good, I'd recommend going the Friday as I suspect the weekend days will be very crowded (we've been twice, both times Friday and it was OK).

That's a very interesting idea.. I might try and make it down there on the Friday. Thank you

 

[Chrishazle]

Beware the speed cameras both sides of the road at the bottom of Detling Hill. Depending on what part of London you're coming from, may be better to access via M2 except you can't turn right across the dual carriageway to get into the showground so have to go a long way to do a U turn! Same when you leave, you have to turn left towards the M2 and go a long way to turn if you want the M20!

 

[D5meister]

I got a brushed milwalkee with 4amp hr battery and its lame, wont undo wheel nuts/bolts.
I rely on a mains powered unit which does 600Nm for stubborn items like diesel crank pully bolts/nuts

 

[joderest]

I know all are going to say waste of money but....
I have just bought a cheap Chinese cordless impact wrench. 21 volt and states 460 NM. I suspect it will be more like 200MN. I have only tried it to slacken off then do up a wheel bolt. Did it with no issue, of course I always use a torque wrench after.
I bought it to save time when taking out long winded bolts once slacked off, saving having to spend time with a ratchet or bar, and to put them in again before tightening with tools.
It was £50, delivered, quality is what you would expect.
Time will tell.

 

[alexanderfoti]

Daily, I use the DCF899 for wheel bolt removal. Spins them on at low torque setting to then be tightened with a torque wrench. I also use it for large suspension bolts etc.

I use a DCF813 for general bolt work 10mm's on engines, trim pieces, etc.

A non genuine battery cannot deliver the current needed and will reduce the torque rating quite a bit. Just something to keep in mind.