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Adjustment and Service of Wheel Bearings

Tools Needed: Pin spanner, Pin wrench, hammer, Tommy bar, 2' extension bar, axle, grease, cleaning basin, solvent, rags and bearing packer (optional).

Use the Pin spanner to loosen outer lock ring. You may need to rap the spanner with a hammer to loosen the ring.


Insert the teeth of the Pin wrench into one set of the holes in the compression nut.


Use the Pin wrench to loosen compression nut. A hammer may be needed again.


Now slip one tooth of the Pin wrench out and spin the compression nut off.


Remove the compression nut taking care to lose the top hat bushing which may drop out.


Here is the Lock ring, Compression nut and Top Hat bushing. Upon re-assembly the brim of the Top Hat bushing goes on the inside.


Stand the wheel up and insert the axle through the wheel from the brake lining side.


Tap lightly with a hammer if needed to pass the axle through to the outside of the wheel.


Angle the drum face up slightly (so nothing falls off axel) and pull the axle through. All bearings and spacers come off in order.


You can clean all the parts on the axle or slide them all off. The inner bearing race and dust cover will remain inside the wheel hub.


View of race and dust cover still in hub. Normally you do not remove these. Just clean them in place.


If you are changing bearings the inner race must be changed also. Use a Tommy bar and hammer to tap the dust cover and race out.


Strike the dust cover at 12, 3, 6 and 9 o'clock alternately and the dust cover and bearing race will come out easily in under 2 minutes.


Clean the hub with your favorite grease solvent.


Here's all the bits & pieces lined up in order. Make sure the longer Top Hat bushing goes on first.


To assemble, put the dust cover in first. Make sure the convex side is facing down.


Let it go, and it should....


...drop straight in and to the bottom. Check and make sure the convex side is still facing down!


Now place the inner race so the face is down and the bearing race in up.


Set it so it is somewhat "square" to the hub channel.


Use the Tommy Bar and hammer in a 12, 6, 3, 9 o'clock pattern to drive the inner race solidly to the bottom of the hub.


View from the top on the race seated on top of the dust cover.


View from the brake lining side of drum. Dust cover may have a small amount of play. Is the convex side facing out?


Packing the bearings is much easier and less messy with a bearing packer. Most auto-parts stores carry these for under $30.


Remove the hand press...


Place the bearing in tapered side down...


...on the shaft of the grease injector.



Place the hand press on top and give a good firm push and remove bearing.


Old grease out! New grease in!

If you are packing your bearings by hand; go to the Timken website and read their "Tech Tips" on how to properly pack a bearing by hand.


Place the long Top hat bushing with the "brim" facing inward on first, then the inner bearing with the taper first, then the spacer, the the outer bearing face first followed by the out race. Place gobs of grease between spacer and bearings.


This grease can be used for "roadside" repairs of bearings and also holds water penetration down a little bit.


Now, slide the axle, non-threaded side first through the drum side...in the picture it is inserted left to right.


Tilt the wheel (brake lining side) down slightly so nothing falls out of the hub and pull the axle completely through.


Lay the wheel down and using the hammer and Tommy bar in the 12, 6, 9, 3 o'clock pattern; seat the outer bearing race flush in the hub.


Shouldn't take more than 30 seconds.


Using the Pin wrench, spin the compression nut on and tighten it as much as you can by hand.


Now you must "pre-load" the bearings. Slip a suitable extension bar over the handle...


...and give the nut another 1/4 turn...


...now back it off 1/8th to 1/4 of a turn and remove the wrench.


Spin the lock ring on being careful not to move the compression nut.


While using the Pin wrench to prevent the compression nut from moving, use the Pin spanner to tighten the lock ring. I stand the wheel up to do this.


A down a dirty way to check for proper bearing tightness is to FULLY insert the axle through the hub...


...and using just the finger tips, rotate the axle. If you feel any "tight" spots; loosen the lock ring and back the compression nut off a hair. Repeat until the axle revolves freely.


If, with the wheel remounted on the bike, you can rock the wheel back and forth on the axle; the bearings are too loose and must be tightened.  
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