How To Rebuild / Refurbish an Air Ratchet

  1. RustyRatRod
    Please keep comments in a separate thread so as not to crowd this one. Thanks.

    sireland67 took me up on my offer to rebuild an air ratchet and provide a How To on how to do it. He sent me an old Mac Tools 1/4 stubby air ratchet. It is actually a variation of the tried and true Ingersoll Rand 103/104 series. Follow along as I tear it down.

    First, here are the necessary tools. As you can see, nuthin to it.

    Air Ratchet Rebuild 1-1.jpg

    First, we remove the snap ring that retains the head in the head driver.


    Air Ratchet Rebuild 2-1.jpg

    Next, I push the head out of the head driver. You have to work with it a little, as they have been married a pretty good while.

    Air Ratchet Rebuild 3-1.jpg

    Next, remove the head collar. Then the front head spring washer. This is an older unit. Newer designs have two springs that push against two balls that provide the friction.

    First picture is the head collar removal then the front spring washer.

    Air Ratchet Rebuild 4-1.jpg

    Air Ratchet Rebuild 4-2.jpg

    Next remove the direction pawl pin, the direction pawl and then the direction switch. Pictures in that order.

    My apologies the pictures are not closer. This was the best Kitty could do with such small parts.

    Air Ratchet Rebuild 5-1.jpg

    Air Ratchet Rebuild 5-2.jpg

    Air Ratchet Rebuild 5-3.jpg

    With the head disassembled, now I remove the head drive, head drive ball and drive shaft. Pictures in that order. There's no magic to any of this. Once the head is out, the upper part of the ratchet basically falls apart.

    Air Ratchet Rebuild 6-1.jpg

    Air Ratchet Rebuild 6-2.jpg

    Air Ratchet Rebuild 6-3.jpg

    Now we turn our attention to the main body. Break the collar retainer nut loose and screw it off, then remove the head housing.

    Air Ratchet Rebuild 7-1.jpg

    Air Ratchet Rebuild 7-2.jpg

    Air Ratchet Rebuild 7-3.jpg

    Now, remove the planetary assembly.

    Air Ratchet Rebuild 8-1.jpg

    Air Ratchet Rebuild 8-2.jpg

    Next, remove the front bearing and the retainer washer behind it.

    Air Ratchet Rebuild 9-1.jpg

    Air Ratchet Rebuild 9-2.jpg

    Air Ratchet Rebuild 9-3.jpg

    Most of the time, getting the actual air motor out is difficult. The clearance between the motor sleeve and the outer housing is tight. Over the years, very small grooves wear and this causes disassembly to be difficult. Usually, gently tapping the main housing on a vise will shake the motor loose. It did for me. First, the motor removal and then the motor sleeve removal.

    Air Ratchet Rebuild 10-1.jpg

    Air Ratchet Rebuild 10-2.jpg

    Now we are down to the motor core with the fiber vanes. Simply slide the vanes out, if they haven't already fallen out.

    Air Ratchet Rebuild 11-1.jpg

    Air Ratchet Rebuild 11-2.jpg

    And that's all there to the disassembly. This particular ratchet was really in very decent shape. The design of the spring washers in the head is not quite as good as the later ball and spring style, but it works. There are unfortunately no parts available for this type head anymore, but that's ok because I can fix it. The actual motor was very strong still. I will soak everything in cleaner and begin reassembly soon. Stay tuned.

    Ok. I got the little ratchet back together and it works pretty dang good for what it is. Unfortunately, is has the old style head which does not use the two springs and ball bearings to preload the head assembly. It uses two wavy washers similar to what a Track Loc limited slip differential uses, but of course much smaller. So here we go with reassembly.

    First, I mark the main body with a sharpie so I will know the orientation of the locator pin in the air motor. You can see the hole for the locator pin in the bottom of the ratchet body.

    Air Ratchet Rebuild 13-1.jpg

    Next, lube the inside of the body up good with air tool oil. Transmission fluid will work fine, but I happened to have some air tool specific oil so that's what I used.

    Air Ratchet Rebuild 14-1.jpg

    Next, assemble the motor in the exact reversal that it came apart. Take care to remember the orientation of the air passage where I showed above in the disassembly. Then, carefully slip the motor into the main body. You may have to end up doing this step a piece at a time, because these parts are such a tight fit into the main body. You CAN very lightly dress the rear bearing plate and the inside of the main body with fine sandpaper, but do NOT remove material. Only smooth out any high spots.

    Air Ratchet Rebuild 15-1.jpg

    Install the front bearing cup, front bearing and washer.

    Air Ratchet Rebuild 16-1.jpg

    Next, comes the planetary assembly. First the planet shell and then the planetary gears.

    Air Ratchet Rebuild 17-1.jpg

    Air Ratchet Rebuild 17-2.jpg

    Now reinstall the head housing and collar. Now the main body is complete.

    Air Ratchet Rebuild 18-1.jpg

    Here are all the parts laid out.

    Air Ratchet Rebuild 19-1.jpg

    I had the head back together before I realized I didn't take any pictures of its reassembly. Sorry about that. Just refer to the disassembly as it is pretty standard for a LOT of air ratchets.

    Lastly, with the addition of every part, don't forget to put a drop or two of lube on everything. Then of course, several drops in the end of the ratchet before firing it up.

    I have a video we shot I am working on uploading of the ratchet in operation. It will be here shortly.

    One last thing. Here is what I do to regain the lost torque in the ratchet head assembly. I reshape the wavy washers over something curved, in this case, some needle nosed pliers worked fine.

    Unfortunately, the service parts for these heads are no longer available, so this is the only option. It may last a while. It may not. But it works good for now.

    Hope yall enjoyed this.

    Air Ratchet Rebuild 20-1.jpg

    Here is the video I promised.

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