ACDelco ARI12104T G12 Series 3/8″ Power Impact Wrench 10.8V

Update: I’m still very pleased with this little impact wrench, but I had occasion to work on my bicycle today, needing to remove a few bits and bobs from it before I parted with the bike. My goodness! This little wrench came into it’s own working on the bike. Small and light enough to allow me to use it easily and it made the job of removing the bits I wanted to keep very quick. I still think you have to buy carefully to make sure you get value for money from the AC Delco range, as with the charger, this tool is pretty pricey. But it’s a very useful little impact wrench.

Original review:
I’m writing this because there’s a good promotion from AC Delco at the moment and it would be a shame to miss out on it because you hesitated to hit “Buy” because of bad reviews that might not tell the whole picture. So for now, I’m just addressing the two big issues.

Firstly, getting sockets on and off. The first few times it’s a pain, until you know what’s happening. If you look at my pics, you’ll see a metal o-ring with a cut in it. This o-ring must be compressed slightly to allow sockets to locate securely on the 3/8″ square drive. The o-ring is mounted on some rubber underneath it, which you can see in the gap. Get a large deep 3/8″ socket (see pic) and that will ensure you can get a good grip on it. As you push the socket onto the 3/8″ drive, note where the gap in the ring is, and wiggle above and below the gap, which will allow the ring to close enough to get the socket on. If you force it the wrong way, you may end up putting pressure on the gap itself, and you’ll open up the ring a little, and end up working against yourself. Be assertive and know that the socket WILL go on. If you’re weak or frail, this could be a struggle. You may find you end-up pushing the socket onto the drive by pressing the driver down onto the socket placed on a hard surface. That’s all well and good, but then you’ve got to get it off again, and if you ignored my advice to get a large deep socket to do this with, you’ll struggle to get a good grip on the socket.

All that sounds like a right palaver, doesn’t it? The good news is, the o-ring quickly wears some flats into it it where the socket rubs over it, and socket changing gets a lot easier pretty quickly. Don’t despair, it will be okay, just keep at it. (If it is all too much bother, Amazon has an excellent return policy that is now easier than ever and doesn’t require a printer.)

The second issue is that of price. I’ve had a look at the prices of the AC Delco range, and frankly, they’re all over the place. However, at the moment there is a great promotion on, where you buy the body-only option, and you get a free battery. The fly in the ointment is you will need to buy one of the tools with a battery and charger, or get a charger from another source. (I already have one of the AC Delco G12 range, so the body + free battery offer without charger worked for me.) If you are just looking for an impact driver and don’t already have something from the G12 range, look elsewhere.

So, about the driver. Pulling the progressive trigger lights up both a front-facing work light and a three stage LED battery indicator on the side. The light is perfect for seeing what you’re doing in dark corners under the car, and the battery indicator works well. The direction switch is labelled simply with directional arrows and has a centre “off” position which locks the trigger so the drive can’t be powered and is sensibly positioned and works pleasingly locating in each position with a positive click.

Build quality is good, and the tool feels reassuringly heavy and solid, without being unwieldy. Personally, I think the G12 range are great tools for casual DIY at home, but might not be up to hard work every day in a workshop, and this impact driver really isn’t going to have enough oomph or speed for a working mechanic, but for the casual amateur they can be a cost-effective solution, especially during the current “free battery” promotion.

In use, without load the drive spins quite quickly with a quiet whirr. When there’s some work to be done, the impact mechanism kicks in accompanied by the familiar percussive impact wrench “Rrrrtrrrtrrrrtrrrrt!” noise (though obviously without the whistle of compressed air). Rotation under load is quite slow, and the impact mechanism cuts in on what I consider to be quite low loads, so even when trying this on the hex end of my scissor jack, the impact mechanism quickly cut in, and raising the car slowed to a crawl. In fairness, it’s not designed for that, but I felt it should have been able to spin it up more easily than it did. It really seemed to make it look like hard work. I’m happy to say that for tightening wheel nuts, this tool worked a treat and set them to the requisite 120Nm on my car without trouble. But 120Nm isn’t a particularly high rating, so if you really need an impact driver, look elsewhere. I bought this drive as an alternative to the slightly underpowered ARW1209P in the hope the rated 120Nm would be enough to raise my car jack easily. Sadly that plan didn’t work out, however with the promotion on, this driver is such good value with the “free” battery and the rated torque coincidentally matches my wheel bolt torque rating, so it’s perfect for my needs and good value.

If you can get past the initial barrier of getting the socket on and off (and if you keep at it, you will), this is a handy tool, but it’s really not beefy enough for a mechanic. If you really need an impact driver, I’d be tempted to look for something with more oomph. 200Nm turning force would be the minimum that I’d be looking for if I actually needed an impact driver, but I doubt you’ll find that for 42.96 with a battery.

Don’t get me wrong, I’m a fan of the G12 range and have 4 of the G12 tools, as for me they hit a sweet spot between power and size. They’re not as powerful as the 18v & 20v gear, but they’re smaller and more convenient. I don’t think this impact driver is a great impact driver, but it’s good enough for me and during this promotion, it’s a great deal if you already have the charger.

If hadn’t got a charger and the promotion wasn’t on, I don’t think I’d go for this product. I’d buy the AC Delco ARI2068-3AEU Li-ion 18V Impact Wrench instead, which offers a two batteries and lot more torque for not much more cash than the two-battery kit version of this product. My 4-star review rating is for value, not performance. If you can’t take advantage of the promotion, knock a star off my review score and shop around.