Bearing Puller

By Bob Butcher

Recently I was replacing the clutch in a car and I needed a
bearing puller to remove the pilot bearing from inside the end

of the crankshaft. There was no access to the backside of the

bearing, so I needed to build a bearing puller that would fit

inside the old bearing and allow me to grip the inner bearing race.

Figure 1 shows a 3D sketch of the bearing installed in the end of

the crankshaft, and a concept drawing of the bearing puller. The

puller consisted of a long threaded bolt (1/4-20 X 3” in this case)
with a head that will fit inside the inner bearing race. I machined

a length of aluminum bar stock about 1 inch long to slightly less

than the diameter of the inside of the old bearing for a length

roughly equal to the thickness of the bearing. The aluminum bar

was then drilled off center and tapped to the same thread as the bolt.

The offset of the tapped hole was close to the maximum I could obtain

and still have some wall thickness after threading the hole, as
shown in Figure 2. The inside thread is not really required; a through

hole would also work, but the thread held everything in place nicely.

The purpose of the offset is to force the bolt head away from the bearing

center until it overlaps the inner race and prevent if from slipping during

bearing removal.

I drilled the aluminum bar off-center using my lathe and a 3
jaw chuck with a piece of scrap between the bar and one jaw of the chuck.

Screw the bolt into the aluminum bar leaving enough of the bolt head

protruding to reach through the bearing.

Press the assembly through the bearing, turning the bolt inside the

aluminum bar as required until the bolt head is completely inside the cavity

behind the bearing. Offset the bolt and allow the aluminum bar to enter the

bearing,turning the bolt as required until the bolt is snug against the

backside of the bearing and the aluminum bar is seated inside the inner

race as shown in Figure 3 and Figure 4. Place a length of tubing (or

perhaps a large socket as I used) with an inside diameter large enough to

accommodate the entire bearing and a length adequate to allow the bearing

to fit completely inside over the bolt. Place a washer and a nut over the end

of the bolt as shown in Figure 5 and Figure 6. Use a wrench or socket to

tighten the nut until the bearing is removed. Note: Since the puller is

pulling more on one side of the bearing, it may cause it to tilt and bind in

the crankshaft. In that case,loosen the nut and rotate the puller 180 ° and

continue. Repeat until the bearing is removed.

Figure1. Puller being inserted into bearing

Figure 2. Aluminum bar with offset tapped hole

Figure 3. Bolt fully inserted in cavity, bar started in bearing

Figure 4. Puller fully inserted in bearing

Figure 5. Tubing, washer, and nut added to puller

Figure 6. Large socket used in place of outer tubing