Tractor trust bearing

Field east

What is the right way to fit a trust bearing onto the stub axle of a tractor? Should the ‘ cup’ side be facing up or down. The cup side has the bearing number on it. The word ‘TOP’ is NOT stamped on it.
The bearings on both wheels were mangled beyond recognition so that guidance is out.
I assume that there should be some way for the bearing to be continually exposed to grease. If that is the case then the cup surface should be underneath when fitted. Greece is supplied by keeping the stub axle housing pumped with grease - unless the bearing is ‘sealed’ with grease for its lifespan ( however long that might be .

OR should the ‘cup’ surface be facing up because that is the part of the bearing that does not move because it is fixed into the stub axle housing which does not twist. In this case it would be essential that the bearing is ‘sealed’ re retaining grease for its lifetime.
Any information would be appreciated

mad-for-tar

Field east wrote: »

What is the right way to fit a trust bearing onto the stub axle of a tractor? Should the ‘ cup’ side be facing up or down. The cup side has the bearing number on it. The word ‘TOP’ is NOT stamped on it.
The bearings on both wheels were mangled beyond recognition so that guidance is out.
I assume that there should be some way for the bearing to be continually exposed to grease. If that is the case then the cup surface should be underneath when fitted. Greece is supplied by keeping the stub axle housing pumped with grease - unless the bearing is ‘sealed’ with grease for its lifespan ( however long that might be .

OR should the ‘cup’ surface be facing up because that is the part of the bearing that does not move because it is fixed into the stub axle housing which does not twist. In this case it would be essential that the bearing is ‘sealed’ re retaining grease for its lifetime.
Any information would be appreciated

What make and model is it? Is it a taper roller bearing setup or another type of bearing?

Usually with taper roller bearing on these, the cup will sit up in the housing of the axle and the cone then will be placed on the stub axle shaft itself, unless you have a receiving area on the stub axle itself that takes the cup of the bearing. If the old bearing is mangled like you say, the cup of the old bearing may still be sitting in the housing, the only way to remove them is to run a ring of weld around the inside of it and usually they will come out with little force or with the use of a slide hammer.
The other type of bearing I have seen is a single race conventional type which has a cover over that comes down over the sides of the bearing, on those that larger side is usually fitted upwards into the housing with the smaller side of the bearing resting on the stub axle itself.

It’s likely you will also have brass bushes in the vertical housings that will need replacing also.

Field east

mad-for-tar wrote: »

What make and model is it? Is it a taper roller bearing setup or another type of bearing?

Usually with taper roller bearing on these, the cup will sit up in the housing of the axle and the cone then will be placed on the stub axle shaft itself, unless you have a receiving area on the stub axle itself that takes the cup of the bearing. If the old bearing is mangled like you say, the cup of the old bearing may still be sitting in the housing, the only way to remove them is to run a ring of weld around the inside of it and usually they will come out with little force or with the use of a slide hammer.
The other type of bearing I have seen is a single race conventional type which has a cover over that comes down over the sides of the bearing, on those that larger side is usually fitted upwards into the housing with the smaller side of the bearing resting on the stub axle itself.


It’s likely you will also have brass bushes in the vertical housings that will need replacing also.

Tks for your response. From what you are saying , the cup is facing downward and therefor , I assume, that the bearing is greased for its lifetime. Tractor is a Leyland 272. Have fitted new brass bushes. I could guess - from the mangled on one side how the bearing was fitted but I am concerned that it might have been fitted the wrong way around. One tester on some site I came across suggested that it does not matter what way it is fitted

mad-for-tar

Looking at pics of the bearing used in these, it’s a similar type as the MF135 etc., where the cover of it comes down over the sides of the bearing. I always installed them facing downwards as the larger diameter of the bearing sat comfortably up in the spindle housing and the smaller part of the bearing rests on the stub axle base itself. This way too they won’t collect water and other debris. You can always pack an extra bit of grease in there before putting the spindle back into the housing.
I’m sure you’ll find that the internal diameter of the axle housing where the bearing sits is the same or should be the same diameter as the outer diameter of the bearing.