REAR HUB BEARING TOO!

AF have finally released their new rear hub bearing kit. They’ve been running these in their own scooters, and 20 selected customers’ engines, since July last year. The FAG Double Row Angular Contact Rear Hub Bearing is a significant upgrade on the original Lambretta design. It offers far better stability for the layshaft while increasing the load rating.

The double labyrinth seal design provides a good seal as well as lower friction than the original garter seal. To fit this bearing you must also purchase the retaining plate to suit. With all this good news comes two provisos. The bearing is 2.6mm wider than the original Lambretta rear hub bearing. As a result the rear hub will sit 2.6mm further out than original. Removing the layshaft cone shim can give back 1mm. It is important that the person assembling the rear hub checks the fitment. The variation in height of rear hub cone location in Lambretta rear hubs is up to 4mm (this is a massive tolerance). As with all aspects of safety check and if in doubt ask.

The second proviso is you must ensure your crankcase breather is not blocked. The pressure holding ability of a labyrinth seal is not as high as the original garter seal. A blocked breather can pressurise the crankcase as it gets hot. Oil will be forced through the rear hub bearing and contaminate the rear brake shoes. The good news is that once the breather is corrected (and brake shoes replaced and drum cleaned) the seals will do their job once more. It is not necessary to replace the bearing if this happens. However, it is easy to avoid the problem by ensuring your breather works. The Double Row Rear Hub Bearing is £35. The retaining plate to suit is £6.90.