B.B. Ingersoll Rand Impact Wrench Tuneup

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CREDITS: This work is NOT mine. I am simply showing pictures of what was done by rec.crafts.metalworking member B.B. who bought this impact from me on eBay. I added a few pictures of the wrench as it was assembled, and a video of it running, which I made to sel this item on eBay.

I didn't bother to take any of the assembled gun since you've got pics of that already. Absolutely not your usual impact.

Camera batteries died, so I couldn't show any detail of putting it back together. It's reassembled now, and once I get a new inlet fitting and an adapter I can give the thing a test. I'm going to stick the other grease fitting in the side of the motor housing, just forward of the front bearing. It way it can grease the front motor bearing and rear hammer bearing together. Excess will work its way into the motor exhaust or the hammer housing. That's the plan, anyway.

This makes up at least half of the gun's mass right here. This is the assembled hammer mechanism outside of the case. The output shaft is held all the way down to the rest of the mechanism by the front bushing. The large dark chunk at the bottom is the flywheel, the lighter piece settled inside of it is the clutch, and the shaft on top is obviously the output. The motor will rev up the flywheel, and a cam buried down in the center will kick the clutch up towards the shaft as the flywheel overtakes the output shaft. The clutch piece will be caught between the flywheel grooves and the three tangs of the output shaft, and you get an impact. Nobody I've shown this to so far have seen this exact kind of impact mechanism except on a hydraulic gun. When I took it apart the grease in here was almost like tar in some places. I don't know it it was just old or if it's a special-purpose grease. It's going back together packed with wheel bearing grease.

Detail of the valve. Air supplied down the axis at the lever end comes out a side port midway down the valve's body. Rotating the valve switches the destination port. The other end of the valve is the same thing, but connects the unpowered side of the motor to the exhaust by way of another side port on the valve body.

Interior of the front housing, showing the bushing and some metal flakes that were floating around up in there. That rough area looks like it's just left over from the initial casting, but for a minute I thought the clutch had been slapping the housing. Photo came out pretty well.

The impact mechanism strewn out across the table. On the right side you can see the cam mechanism. The roller slips over the pin, and the pin goes in the small hole in the side of the flywheel. The piece to the left is the actual cam, it's splined to the output shaft and rides against the clutch piece. There's a small dowel pin inside of the output shaft to hold the long splined shaft in place. When assembled the spring is almost completely inside of the output shaft.

More detail on the flywheel piece.

The depression is room for the rear motor bearing and grease. It was mostly empty when I took the gun apart, just had a little residue from the old bearing grease. I'm going to install one grease fitting back here so I can stuff fresh grease in there every so often. On the right you can see the supply to the direction control valve and inside of that the brass port for the lubricator.

The inlet fitting took a hell of a lot of work to take out. Ripped out a few threads, but not enough to be a problem. OTOH, that pipe nipple didn't want to come out of the fitting. I tried, finally broke it. Lots of torching later, still no progress. I'm going to replace it, threads were damaged anyway. Somebody put that strainer in upside down.

Shows the porting to the motor. The two grommets are the air supplies, forward on the left, reverse on the right. The small hole in the bottom at the back is for the alignment pin for the air motor. The other three holes are exhaust, they're ported to the exhaust on the outside of the gun.

The pieces of the air motor, the bearings were filled with lubriplate just to make sure no other junk got in 'em on the way home. Brass endplates, about 1/4" thick, steel bore lined with something. Kind of resembles babbitt. Six rotor vanes, plastic, and look brand new. The rotor shaft is actually hollow down the center. Vents excess grease from the rear bearing through into the hammer housing. Those bearings sounded like crap when I took it apart. I knocked off the shields and cleaned them out. For some reason I've found small aluminum flakes throughout this gun, and some were even inside of the bearings. But after cleaning them up all looked OK, so I'm going to put it back together with the original bearings and see if they last. Eventually I intend to add a couple of grease fittings to the housing so I can maintain the bearings without tearing the gun down.

The lining was flaking in a couple of places. I removed anything that was already loose. There are also a few pinholes scattered around the interior. I don't know if it wasn't put in right or if it's damage after-the-fact, but there is no scoring or corrosion. It's extremely smooth to the touch.

From let to right, hammer case, motor housing, handle. The gun had eight bolts holding it together. All have been helicoiled. What's interesting is that the gun seems to have been put together from at least two different guns in the past. According to a buddy who rebuilds air tools on the side, the motor housing and handle are apparently from an IR2138, and the hammer and hammer case are from a hydraulic powered impact. Maybe a Stanley, or maybe something off a tank. Somebody took the time to find a couple that matched up just right. The motor housing and handle together weigh maybe a pound and a half or so. All aluminum, mostly hollow. The hammer case is between 1/4" and 3/8" steel all over, and weighs around seven or eight pounds enpty. No scale, so guesstimations abound.