MF50 rear wheel locks up

[ken ontario]

I have a 1962 MF50 4cyl gas tractor. Sometimes when I'm snow blowing in reverse the left rear wheel locks up. Forward is OK. Go back and forth and the wheel frees itself. I've disconnected the brake rod and have had the wheel off. All looks OK. I don't think this happens in the summer but I don't do much work in reverse in the summer. Is there something going on in the diff?

 

[Timmy1957]

Never heard of that. Were both wheels locked up or just one? Probably at the time it was hard to tell.

 

[LouNY]

I'm not familiar with your MF but on IH's it's quite easy to sometimes get a little brake applied while twisted around,
and when the brakes are some what worn they do become self energizing and will lock up a wheel.
Power in the opposite direction will unlock them.

 

[ken ontario]

Never heard of that. Were both wheels locked up or just one? Probably at the time it was hard to tell.

No. Just the left side when I'm going in reverse. Going to take the brake shoes off and take it from there.

 

[ken ontario]

I'm not familiar with your MF but on IH's it's quite easy to sometimes get a little brake applied while twisted around,
and when the brakes are some what worn they do become self energizing and will lock up a wheel.
Power in the opposite direction will unlock them.

OK. Thanks. I don't think that is the case this time.

 

[07wingnut]

Drum brakes can be either leading or lagging or leading/lagging design. A leading shoe is one that rotates in the direction of the drum. A lagging shoe is one that rotates in the opposite direction of the drum (shoe rotation refers to the tiny amount the shoe moves when braking). A leading/lagging brake setup will brake the same in forward or reverse. A leading brake shoe tends to brake harder than a lagging one, because once it contacts the drum, the rotation of the drum tends to pull the shoe into more engagement. If you have a double lagging design brake shoe on your tractor, it becomes a double leading design in reverse and would be much more liable to engage if one of the shoes contacts the drum. Even a leading/lagging brake system could do this if one of the shoes has a very weak spring. I would have a really close look at those springs.

 

[ken ontario]

Drum brakes can be either leading or lagging or leading/lagging design. A leading shoe is one that rotates in the direction of the drum. A lagging shoe is one that rotates in the opposite direction of the drum (shoe rotation refers to the tiny amount the shoe moves when braking). A leading/lagging brake setup will brake the same in forward or reverse. A leading brake shoe tends to brake harder than a lagging one, because once it contacts the drum, the rotation of the drum tends to pull the shoe into more engagement. If you have a double lagging design brake shoe on your tractor, it becomes a double leading design in reverse and would be much more liable to engage if one of the shoes contacts the drum. Even a leading/lagging brake system could do this if one of the shoes has a very weak spring. I would have a really close look at those springs.

Right now I have the brake rod disconnected and the same. Don't know what that tells me since the shaft into the wheel rotates back and forth a little with a pipe wrench. It happened last winter and I disconnected the rod and the problem disappeared by coincidence. Now it has happened again twice this winter with the rod disconnected. Why oh why didn't I investigate in the summer. Now it's -15 degrees C or 5F until March. Some other people think maybe loose backing plate or broken cap screws on the crown gear. Going to take the wheel off and look at the springs and backing plate.

 

[ken ontario]

Well I took the shoes off. The backing plate was tight and the springs were fine. No signs of funny rubbing or wear. Did about 1/4 mile of snow blowing and no issues. Will have to wait and see.