DIY grain mill repair?

[Franktalk]

I have a JSP Malt Mill, which I love. The bushing on the drive shaft has worn, and there is give between the rollers. My efficiency is suffering as a result.

My questions are:
How difficult is it to replace the bushing?
Do I need specialized tools to get the old one out or to press the replacement in?

Any help I can get is appreciated. Thanks.

 

[Dland]

If you are mechanically inclined and have tools, it should not be difficult. If this is the first repair of this sort, you should take your time. No comment on specifics, as am not familiar with your mill.

My guess is that once shaft is removed, bushing should press or be knocked out with light blows with small hammer,(preferably brass, plastic or very small) and drift of slightly smaller diameter than the bushing. One can usually use 1/4 inch drive sockets as drifts in this sort of case.

 

[Franktalk]

That's solid advice; thank you!

 

[bruce_the_loon]

Adding to Dland's response, getting the old bushing out can be done with a hammer and something tubular to push against the face of the bushing.

Getting the new one in needs a bit more trickery. If the bushing is the porous bronze type, it needs to be soaked in oil for a few days. This will then lubricate the shaft going forward.

Getting the bushing in can be made easier by using temperature to assist. Freeze the bushing in the coldest freezer you can find, and if you can heat the frame, do so. The bushing will shrink and the hole in the frame will expand a little and the bushing will go in a bit easier.

If you have a suitable G clamp, you can use it to press the bushing into the hole. A flat metal plate or large washer between the moving disk at the end of the screw and the bushing to evenly spread the load. Take it out of the freezer and act fast.

 

[Mike_kever_kombi]

A socket slightly larger than the bushing against the frame on inside, a socket slightly smaller than the bushing, against the bushing on the outside. A piece of all thread through the sockets and bushing, with washers and nuts on outside of sockets. Tighten the nut on the bushing side and it will push the bushing out. Install is the opposite

 

[Franktalk]

If you are mechanically inclined and have tools, it should not be difficult. If this is the first repair of this sort, you should take your time. No comment on specifics, as am not familiar with your mill.

My guess is that once shaft is removed, bushing should press or be knocked out with light blows with small hammer,(preferably brass, plastic or very small) and drift of slightly smaller diameter than the bushing. One can usually use 1/4 inch drive sockets as drifts in this sort of case.

Dland, I followed your directions exactly, and it went perfectly! Thank you again!

Adding to Dland's response, getting the old bushing out can be done with a hammer and something tubular to push against the face of the bushing.

Getting the new one in needs a bit more trickery. If the bushing is the porous bronze type, it needs to be soaked in oil for a few days. This will then lubricate the shaft going forward.

Getting the bushing in can be made easier by using temperature to assist. Freeze the bushing in the coldest freezer you can find, and if you can heat the frame, do so. The bushing will shrink and the hole in the frame will expand a little and the bushing will go in a bit easier.

If you have a suitable G clamp, you can use it to press the bushing into the hole. A flat metal plate or large washer between the moving disk at the end of the screw and the bushing to evenly spread the load. Take it out of the freezer and act fast.

Bruce, you're not a loon at all! I used my bench vise to gently push it in. Thanks!

A socket slightly larger than the bushing against the frame on inside, a socket slightly smaller than the bushing, against the bushing on the outside. A piece of all thread through the sockets and bushing, with washers and nuts on outside of sockets. Tighten the nut on the bushing side and it will push the bushing out. Install is the opposite

Mike, I saw this on youtube, and I was going to do it if the simple tapping it out didn't work. Thanks for chiming in to help!

 

[bruce_the_loon]

Glad to hear it worked out.

 

[Spartan1979]

Dland, I followed your directions exactly, and it went perfectly! Thank you again!



Bruce, you're not a loon at all! I used my bench vise to gently push it in. Thanks!



Mike, I saw this on youtube, and I was going to do it if the simple tapping it out didn't work. Thanks for chiming in to help!

I have one of these mills. Where did you get new bushings?

 

[Franktalk]

McMaster-Carr: Oil impregnated, bronze bearings for 3/8" shaft, 1/2" X 1/2"

 

[Tobor_8thMan]

I too have the same mill. Used it for many years. The mill probably had the same problem. I purchased an MM3 to replace it.

 

[Franktalk]

I too have the same mill. Used it for many years. The mill probably had the same problem. I purchased an MM3 to replace it.

I would have had to replace it if I couldn't fix it; though, I didn't want to spend the $$$. As it went, it cost me $1.33 and less than 30 minutes of my time, and the mill is like brand new.