O rings to lock drill in High

Does anyone know the exact size O ring needed to do this?

I tried to find the O-rings but couldn’t et the right ones, we ended up just making a slice of aluminum bent around the inside of the housing to lock it into gear, I can get the dimension in a few minutes when I take it apart.


drill a hole in the nearest piece of metal and run a zip tie from the little piece of metal used to switch gears to the hole. Then just pull tight. Its the one part of our drive that did work last year. :slight_smile:

If I recall correctly, you can cut a slice of 1-1/2" PVC pipe and that will work. I can’t remember the exact size because we just fiddled with it and a sander until it fit. That was a couple of years ago. -Joe

There are only external teeth on the output shaft side of the ring that is used to shift from high to low. The motor side is smooth.

If you take the ring out and put it in smooth side toward the output shaft, the transmission cannot shift into low gear.

This is the easiest way to look the drill transmissions into high gear.

As to the right O-ring to buy from Small Parts to lock the ring in low gear, I THOUGHT that Chris Mikus had it posted on his Nuts4First.net site but I could not find it (actually, I may have the URL wrong, because I could not even find the site!).

If anybody finds Chris’ site, let us know what the part number is.

Joe J.

To keep the drill motor in low use this:

1 1/4" aluminum pipe (that should be 1 1/4" inside diameter)
Turn the Outside diameter down to ~ 1.44"(36.6 mm)
Thickness should be ~ 0.173"(4.4 mm)

We have used this the last 2 years and it works.


I’m not exactly sure which size O ring is needed to lock the gearbox in high gear. At the time I made the discovery I had a handful of rings and used what ever fit.

Here is what I think I used, Small Parts number: U-ORB-218 (1-1/4" ID x 1-1/2" OD x 1/8") use two of these stacked on top of one another.

I’ve recently found that metric sizes fit better (purchased at a local store) but Small Parts doesn’t stock those, so they are against the rules.

Chris Mikus