Dismantling

Both hubs run on journal type non-adjustable ball races. They are packed with suitable grease during original assembly, and this is usually sufficient to last, in normal working conditions, until the time comes to overhaul the entire machine.

The construction of front and rear hubs is identical. The staggering of the rims varies however so that to prevent them being interchanged the front hub is not cut with driving splines. The method of dismantling applies equally to both. The bearings can be repacked with grease without completely dismantling them.

Prise off the hub dust cover, and unscrew the lock-ring underneath it using Spanner LET781 (Fig. 40). It is easier to hold the spanner in a vice, working end upwards, and place the wheel over it with the slots in the lock-ring engaged with the projections on the spanner. Pull the wheel round anti-clockwise until the ring is unscrewed. Lift the wheel off. A grease retaining ring from behind the lock-ring should fall out.

Insert a soft metal drift into the end of the hollow spindle and drive out the hollow spindle towards the end from which the lock-ring was taken. The spindle will bring one ballrace out with it.

This is as far as dismantling need proceed if it is only required to repack the ballraces with grease. Use only high melting point grease for hub lubrication.

The rest of the dismantling is done by removing the distance piece from inside the hub and pressing the ballrace into the hub barrel. The barrel is larger in diameter than the bearing housings, and after the ballrace is free it must be lined up with the bearing housing remote from the brake, and when square can be pressed through and out of the hub. The remaining grease retainer can now be removed.

Reassembling

Rest the brake drum on a firm flat surface and place the grease retainer, convex side downwards in the ballrace housing. Fit the ballrace squarely into the upper housing, press it through, applying pressure to the outer ring only—not in any circumstances to the inner. Centralise it with the lower housing and press it home firmly to nip the grease retainer. Pack the hub with high melting point grease, working it well into the ballrace.

The ballrace that came away with the hollow spindle can be inspected, and if in need of renewal pressed off. If a new ballrace is fitted apply the pressure to the inner ring, only pressing it right up to the shoulder. After working some grease into the bearing, fit the distance piece, and enter the other end of the hollow spindle into the inner ring of the ballrace in the hub, and centralise the ballrace with the upper ballrace housing. Apply pressure to the outer ring of the bearing only and press it home fully. Place the second grease retainer over the ballrace, concave (depressed) side to the bearing, fit the lock-ring and tighten it securely.

Wipe off excess grease and press the outer dust cover on to the protruding end of the hollow spindle.