TO DISMANTLE THE S3B HUB
1. Remove left-hand locknut and brake adjuster nut. Lift out brake assembly.
2. Remove cone locknut and cone.
3. Unscrew right-hand ball ring from hub shell, using hammer and punch and
withdraw internals as a complete unit. One notch of the right-hand ball ring
should be marked and a piece of string or adhesive tape attached to spoke
adjacent to the marked notch.
The reason for this is that the right-hand ball ring has a two-start thread and
must be replaced in the same position to avoid having to retrue wheel after
re-assembly.
4. Remove the low gear pawls, pins and springs. The pawl pins are easily pushed
out of the planet cage to release the pawls and springs.
5. Place the left-hand end of the axle in a vice and remove the right-hand locknut,
washers if any, cone lock washer and cone, making a note of their arrangement
so that they can be replaced in their original positions.
6. Lift off, in the following order, the clutch spring and its cap, the driver, the
right-hand ball ring and the gear ring.
7. Remove the gear ring pawls, pins and springs. The pawl pins are easily pushed
out of the gear ring to release the pawls and springs.
8. Remove thrust ring and unscrew the indicator rod.
9, Push out the axle key and remove the sliding clutch and sleeve.
101 Lift off the planet cage complete.
111 Take Out the pron pins and remove the pinions from the planet cage.
POINTS TO CHOI
1. Slide the clutch up and down the driver prongs and check that the movement
is free.
2. See that there are exactly 24 balls (3/16" diameter) in the right-hand ball ring.
3. Examine the gear ring for cracks, chipping, or signs of wear on the internal
splines and teeth. Check also gear ring pawls for wear.
4. Check the truth of the axle between centres.
5. Examine all ball races for pitting or signs of wear.
6. Examine the sliding clutch for signs of wear (rounding off at the points of
engagement).
7. Examine all pinion teeth for signs of wear or chipping.
8. Examine the pinion pin ends for wear.
9. Examine the brake linings for signs of wear or oil.
10. Check that brake drum is free from oil.
TO RE-ASSEMBLE THE S38 HUB
1. Prepare the following preliminary sub-assemblies:
a. Fit the ball cage into the driver, with the ring of the ball-retainer facing
outwards and the recess in the dust cap also facing outwards. If a new
ball-retainer is being fitted, the dust cap also should be new. Replace the
sprocket and spacing washers in the arrangement noted when dismantling,
and add the circlip.
b. Fit the balls (only 24) and the inner dust cap to the right-hand ball ring,
making sure that the balls can revolve freely with the dust cap in place.
c. Fit the pawls, pins and springs into the gear ring. Place the gear ring, with
the teeth downwards, on a flat surface. Place a pawl spring along the side
of a pawl so that the loop is over the pin hole and the foot is under the
long nose of the pawl. While holding a pawl pin ready in the left-hand,
grip the nose of the pawl and the foot of the spring between the thumb and
forefinger of the right-hand and slide the pawl, tail first, between the flanges
of the gear ring. When the hole in the pawl and the loop in the spring
coincide with the holes in the flanges, push the pawl pin into position.
d. Smear grease in the channels of the dust caps of the driver and in the recess
of the right-hand ball ring. Do not use grease anywhere else.
2. Hold the left-hand end of the axle in a vice, so that the slot for the axle key
is above the sun pinion, and fit the planet cage.
3. Add the planet pinions and pins. (Small ends of the pins protrude).
4. Fit the sleeve (flange first), the sliding clutch (with the recess over the flange of
the sleeve), and the axle key (with the flat of the key facing upwards), and
screw in the indicator rod to hold them in that position.
5. Fit the thrust ring making sure that the flatted ends of the key engage
properly in the slots of the thrust ring.
6. Fit the previously prepared gear-ring sub-assembly.
7. Fit the previously prepared right-hand ball-ring sub-assembly.
8. Fit the previously prepared driver sub-assembly.
9. Drop the clutch spring over the axle.
10. Screw up the right-hand cone finger-tight. Then slacken it back half a turn
and lock it in that position with the special washer and locknut. On no account
must the cone be unscrewed more than half a turn, as that would throw the
gear mechanism out of adjustment.
11. Invert the assembly in the vice and fit the planet-cage pawls. Place a pawl
between the flanges, with the flat top surface pointing towards the right, and
insert a pawl pin through the outside flange and half-way through the pawl.
With tweezers grip the bent leg of the pawl spring in the right-hand and pass
the spring along the side of the pawl until the loop of the spring is in line with
the hole through the pawl and both legs of the spring are between the pawl
and the planet cage. The pawl pin can now be pushed right in.
12. Remove the assembled mechanism from the vice and, while holding it with
the planet cage uppermost„ pour about two teaspoonsfuls of Sturmey-Archer
oil into the cage. 1
13. Hold the cycle wheel in the left-hand, with the open (right-hand) end of the
hub shell facing downwards, and insert the assembled mechanism from below,
screwing up the right-hand ball ring finger-tight only.
14. Make sure that the ball ring comes into the same position as noted before
dismantling and then screw up tightly.
15. Fit the left-hand cone and locking-nut.
16. Replace the brake plate complete with shoes.
17. Fit the brake adjusting nut and the locknut.
18. Replace the wheel in the cycle frame and adjust the gear.
