Installing Motor Bearings without a Press

gunner66 · Post by **gunner66** » Sun Apr 24, 2011 8:31 pm

Hello everyone -

I have decided that I should replace the bearings in my 3/4 hp GE motor. In several posts I saw mention and use of the Harbor Freight Bearing Separator and Puller Set (#93980) being used to remove and install bearings - one stating that you could install motor bearings with the set.

The rotor center with the copper bars is so large in diameter that I don't see how one gets the side-to-side clearance with the set's two side arms when pulling on the new bearing. What am I missing? Can the rotor center be removed from the shaft?

Also - can the bearings be installed without a press some other way?

Thanks in advance, Chris in GA

JPG · Post by **JPG** » Sun Apr 24, 2011 10:11 pm

The 'no-no' when installing the bearings on a shaft is to never-never apply pressure to the outer race. That puts stress on the bearings and the race surfaces.

However pressure can be applied to the center race, but must be done so in line with the shaft center. A close fitting pipe/tubing that will press the center race without putting pressure on the outer race can be used. The end must be square so as to NOT cock the bearing on the shaft. Gentle taping can then be used to 'slip' the bearing in place. Placing the armature in the freezer overnite to 'shrink' the shaft makes it easier.

Although the HF press is preferable, the armature is in the way on the motor shafts.

The info above applies to putting a bearing on shaft. When putting a bearing in a bore, only the outer race may be pressed.

P.S. An extension(wider spacing) can be made so as to allow wider spacing of the 'connecting rods' on the HF puller.

jcraigie · Post by **jcraigie** » Sun Apr 24, 2011 10:15 pm

When I did mine I put the rotor in the freezer for a couple of hours and heated the bearing to 190 deg F then I used a piece of copper pipe and a rubber mallet and TAPPED the bearing into the seated position. I did it quickly while I still had the temp difference and it went on in I think 3 little taps. As JPG said the right size pipe will rest on the center race only. The end beaning went into the outer casing without any force other than my hand, wiggle wiggle and a slight shove.

wannabewoodworker · Post by **wannabewoodworker** » Mon Apr 25, 2011 8:03 am

I just did the motor bearings on my 83' Mark V 1.25 hp. motor and there was nt need to freeze or heat. Just tap the bearing on to get it squarely seated then I put the whole thing in the vise so that the inner race was supported by the vise jaws. Then I used a big sledge hammer to tap the bearing all the way down the shaft. They go on pretty easily if you have to hit it really hard there is something wrong and you should stop immediately.

JPG · Post by **JPG** » Mon Apr 25, 2011 1:26 pm

wannabewoodworker wrote:I just did the motor bearings on my 83' Mark V 1.25 hp. motor and there was nt need to freeze or heat. Just tap the bearing on to get it squarely seated then I put the whole thing in the vise so that the inner race was supported by the vise jaws. Then I used a big sledge hammer to tap the bearing all the way down the shaft. They go on pretty easily if you have to hit it really hard there is something wrong and you should stop immediately.

Yes! Do stop prior to picking up a BIG sledge hammer!!!;)

Easy does it here! If gentle tapping does not get it, remove and start over!

A 'normal' hammer will suffice as long as it is not moving too fast as it strikes the opposite end of the 'pipe'. You need the 'shock' of steel on steel, just not too much at a time.

wannabewoodworker · Post by **wannabewoodworker** » Mon Apr 25, 2011 11:13 pm

I should have said I rested the inner bearing race on the spread apart vise jaws for support. I did not put the shaft actually in the vise as that would be grabbing the outer bearing race plus would just be a really bad idea all together.

gunner66 · Post by **gunner66** » Thu Apr 28, 2011 1:57 pm

I bought that Harbor Freight Puller and was very satisfied with its quality and performance. I was able to remove and install the bearings on the motor (2 bearings) and drive shaft (2 bearings) in about 30 minutes. It came with both large and small jaws so I was able to pull/push only the inner races and clear everything else. The tension on the screw down bolt gives excellent feedback to help you know that you are pulling the bearing on straight and smoothly. Thanks again for all the above advice.

hcbph · Post by **hcbph** » Wed May 04, 2011 1:12 pm

gunner66 wrote:I bought that Harbor Freight Puller and was very satisfied with its quality and performance.

Don't forget this has 3/8" threads. Get yourself some lengths of 3/8" threaded rod (2 of them plus some nuts) and it's surprising some of the things you'll think up it can help you with.

JPG · Post by **JPG** » Wed May 04, 2011 8:02 pm

hcbph wrote:Don't forget this has 3/8" threads. Get yourself some lengths of 3/8" threaded rod (2 of them plus some nuts) and it's surprising some of the things you'll think up it can help you with.

Get some washers also!;)

SDSSmith · Post by **SDSSmith** » Wed May 04, 2011 9:27 pm

Press???? You would be surprised what you can accomplish with some 2x4's and a hydraulic bottle jack.
[ATTACH]12860[/ATTACH]
This has gotten a fair amount of use on motors and drive sleeves. I make hardwood accessories bored for the appropriate shaft size. So far so good.

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