Brakes, Weels and Tyres

H

1971 and later models - See Fig. H6.

With the exception that the later rear hub has two single row ball journal bearings in the hub, rather than a single row bearing at the lockring (speedometer) side and a double row bearing at the brake drum side, the dismantling and reassembly details are the same as for the previous wheel. Later models incorporate shock absorber segments in the hub and to ensure rigidity of the wheel a double row bearing is incorporated in the brake drum itself. The brake drum bearing is dealt with separately.

SECTION H5

REAR HUB REASSEMBLY

Prior to reasembly, clean and inspect the bearings, felt seal and seal retainers for roughness, wear, damage or corrosion and make replacements as necessary. Procced as follows:

Pre 1971 models

1

Pack bearings with the recommended grade of grease (see Section K1).

2

Fit the single row bearing into the threaded (lockring) side of the hub, sufficiently to allow the lockring to be fitted.

3

Fit the felt seal and locking ring and tighten. Remember that the lockring is LEFT HAND threaded. Tighten with peg spanner tool 063965. If the peg spanner is not available, take special care not to damage the slots which drive the speedometer drive box.

4

Fit the bearing spacer tube. On pre 1971 models which have a double row bearing at the brake side and a single row bearing at the speedometer drive box side, the bearing spacer has unequal length ends and the long end locates to the single row bearing.

5

Press the brake drum side bearing (on pre 1971 models a double row and on 1971 and later models, a single row bearing) squarely into position in the hub and drive home applying load only to the outer race. Load on the centre race can cause damage.

6

Fit the felt retaining washer, felt seal and dished washer and on pre 1971 models, lightly peen the dished washer into position. 1971 and later models use a push in washer.

The brake drum and sprocket contain the dummy axle and, in the case of 1971 and later models, the double row bearing and sealing felt. The bearing can be removed and refitted to the later brake drum and sprocket as detailed below.

1971 and later models

The later type of rear wheel incorporating a shock absorber is supported by two single row bearings in the hub and a double row bearing in the brake drum. The brake and brake drum are separated from the swinging fork as detailed in Section H3. To remove and replace the double row bearing and seals, proceed as follows:

1

Lift the brake assembly away from the drum.

2

Remove the bearing spacer (the shouldered spacer protruding from the centre of the bearing towards the wheel). This will be a relatively tight fit into the bearing and may need to be gripped in a vice whilst the brake drum is tapped carefully away from it.

3

Prise out the lipped washer covering the felt seal.

4

Collect the felt seal and felt retaining washer.

5

Using circlip pliers, remove the large bearing retaining circlip.

6

Using a hide hammer or mallet, drive the threaded end of the dummy axle. This should pass into the brake drum, displacing the inner felt seal and retainers and driving the double row bearing clear.

7

Clean, inspect and replace as necessary the bearing, seals and retainers. Check that the shock absorber "paddies" are secure in the brake drum.

8

Pack the bearing with the recommended grade of grease (see Section K 1 ) .

9

Fit the inner washers to the brake drum, holding in place by inserting the dummy axle, threaded end through towards the brake side.

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