Armature Bearing Repair

When Ian posted that he had disassembled and reassembled his compressor electric motor to effect an armature bearing repair, I asked him for details so I could provide them for you.

I very much appreciate that he provided the following, and hope that it provides valuable information for you to.

Armature Bearing Repair

It's not hard, but I didn't take any in process photos.

1. First, and most importantly, unplug the compressor.

2. Take the guard off the V belt. It should be 1 bolt in the middle and then a little work with a flat tip screwdriver to separate the guard halves.

3. Remove the belt. You can either loosen the motor mount to get some slack in the belt, or what I did is pull the belt to one side with one hand while manually turning the pump pulley with the other. The belt will roll off the smaller pulley. It will go back on the same way and you don't have to realign the motor and pump or try to adjust the belt tension when you're done.

4. Take the pulley off the motor. There's a set screw on the back of the pulley that you have to loosen and then you'll need a gear puller (available at your local auto parts store)to remove the pulley. There will be a square key that comes off with it. Take care not to lose it.

5. On the body of the motor there are 4 bolts that go all the way from one end to the other. Take those out.

6. The (motor) end covers should be loose now. The bearings are seated in these covers. You'll have to wiggle them back and forth a little bit to get them free.

7. When you get the end covers free from the bearings, pull the rear cover aside so that you can carefully slide the armature out of the motor windings. The rear cover will have the power wire going to it and then to the motor windings, so you can't remove it. Be careful not to damage or stress any of that connecting wire.

8. Now you have the armature with bearings out of the motor housing. You should be able to use the same gear puller to remove the bearings in a similar manner as you took the pulley off. There are one or two washers between the bearing and caps. Take care not to lose them and take note which end they go in and how many. I had 2 in one end and one in the other.

9. For replacement bearings, you can either order OEM bearings from the mfg or go to a local parts house and probably get a better quality replacement bearing. Take the old bearings in and they can match them.

10. Use some emery cloth or a course scotch brite pad to clean/polish the ends of the armature where the bearings and pulley were.

11. A machine shop can press the new bearings onto the armature for you. Shouldn't take them 10 minutes.

12. Once you have the new bearings on, reassemble the motor in reverse order. If you have trouble getting the bearings back into the motor ends, confirm that the cover and the bearing are square to each other and tap the end caps gently with a soft face hammer. Do not use a metal hammer. You will damage the end caps.

And again, thanks very much Ian, for this info.