Ordered this because I had a bunch of work that I wanted to do on my two vehicles. This work included brakes all the way around along with overhauling all of the front suspension and steering components. I'm going to give my review based on what I think the average "shade tree mechanic"/ home DIY auto enthusiast will need in a tool SYSTEM (including compressor and air hose, fittings, etc) , and what this tool does and does not provide. 1. This tool came in just a cardboard box that was poorly sealed, and had an instruction booklet that was about 30 pages (in as many languages). There were no instruction for use whatsoever. This isn't a big issue, especially if like me, you're familiar with air tools and have experience with them, but even a quick quide of some sorts could be useful to some folks. You can find instructions online lumped in with the other tools in the IR 230 series, but they are still generic and not very useful. You will need to supply your own air fitting-I recommend you get the Milton high-flow kit for about $20. This really helps flow rates from compressor all the way to the tool. Also, to help with volume and flow rates, you'll want the largest Inner diameter hose with the shorter length practical for your work. A 3/8 diameter, 25 foot hose is probably the best compromise, and decent quality hoses can be found for reasonable deals. 2.In order to get the most out of this tool, you need to have an air compressor with good volume (20 gallons at least IMO), and a good flow rate of at least 4.0 CFM and a quick refill rate. Without the former, your compressor will not keep up with this impact, and you'll struggle to get anywhere near peak performance. Also, if you don't have a filter+water separator, you must add one. I added a cheap $8 one from Harbor Freight, and was very impressed by how much better the tool ran afterwards. I ran a short length of air hose from the compressor to the filter, which I zip-tied to the compressor, then put a quick connect coming from the filter out. 3. Lets get to the impact itself. I bought this hoping that it would be able to handle all the suspension bolts, brake caliper bolts, and everything else that I needed it to do. The 231 is marketed as having a "peak torque of 600 ft lbs" but the actual working torque of the tool is listed at 450. That means that even with an ideal setup, the most torque you'll see with the tool running at 90psi (at the tool) is 450. Even with high flow fittings, good compressor and good hose, this was not enough to do a lot of the work that I had lined up. I still had to use a breaker bar on about 1/3 of the larger fasteners such as strut bolts, control arm bolts, and even some caliper bolts. A. The control settings on this tool are not explained and it can be confusing. Basically there are 5 power settings for the internal regulator, but what isn't obvious is that when you have it in any of the 5 power settings for fastening, then switch it to reverse, it will always be on full reverse power, even though the indicator on the reverse side won't line up with any of the numbers. HOWEVER, if you have it on any of the reverse settings, and then switch it to forward, it will be on a reduced power setting. This can be very confusing at first, and there are no instructions which explain this. I personally see no need for different reverse power settings, and wish that they didn't use one knob and regulator for both forward and reverse. Most people will always want full torque in reverse. Impacts generally dont break fasteners upon loosening, even when they are very rusted. The hammering motion of the impact breaks rust free, unlike using a cheater bar when the fastener will just twist at the weakest (thinnest) part. Another issue with the controls is that there are no positive stops either at 1 or at 5. This makes it very easy to go past the torque you are looking for. This is a design flaw that IR must have intentionally let go, because it was the only way to make it so that the power regulator could work for both directions. The result is a control that spins 360 degrees and essentially has more than 5 actual settings. Technically you shouldn't ever use an impact to tighten fasteners to their final torque, so the multiple power settings are pointless, and without being able to confidently know what setting you are on, snapping bolts can happen quickly. B. Oil this tool A LOT (10 -20 drops) before first use, and then oil it AFTER each subsequent use about 5 drops. The heavy initial oiling is to coat the seals and get rid of moisture. After that first initial oiling, be aware that this tool spits oil at whatever it is pointed at. I hated this. Nothing like installing expensive suspension components, only to fling oil all over everything. A lot of impacts use an exhaust that comes out the bottom somewhere near the air inlet, but no this one. Be especially aware of this feature if you'll use this for brake work, because it will coat the pads and rotors in a film of oil if used pointed at them. In summary, this is a decent tool, but you need to be aware of the quirks of the design. Also, the tool will only perform as good as your system. You need an adequate volume of dry compressed air with at least 90 psi at the gun. If you dont have this, expect to either be disappointed or spend a good chunk of change on upgrading your compressor setup. I ended up turning my compressor up to 130 psi to get the tool to perform anywhere near what I thought that it should. I did end up returning this tool and buying a high quality 1/2 inch battery powered impact which will work circles around this all day long. While the cordless was more expensive, I would have had even more into trying to get the IR anywhere near the same performance, and still been left using a breaker bar too often. Last but not least, if you plan to use this while under a car on a creeper, you'll find out first hand how annoying a dragging air hose can be as you constantly are getting your creeper wheels stuck on it while trying to roll around and work. This wont be an issue if you have shop air coming from a ceiling, but is a valid concern for home mechanics who run their air across the flow from the compressor. I would not recommend this to anyone who wants to do a lot of work. For the occasional task it might be fine, but most people will find it lacking with the air system they already have.
