I mentioned elsewhere that the differential bearings were the weakpoint of the gearbox, so what can we do about it? Well there are a couple of options.
The normal ones are normal ball races with plastic cages. The plastic cages tend to break up meaning the balls skid against each other and all end up on one side of the ball race causing rapid wear and oil leaks.
The upgrades are:
Steel/metal caged bearings – the cages are tougher and so last better
Steel cages bearings with more balls in them – These have a higher load capacity than the standard bearings and also have the steel cages so are a good easy upgrade.
Taper roller bearings – These are much harder to setup as they need machining and careful setup to make them work well but they are the toughest bearings available. Probably overkill for the torque and power figures we are looking at but worth bearing in mind.
To change the bearings the gearbox has to be removed and completely disassembled so it isn’t for the faint hearted! I’ve done a few but I don’t generally offer this as a service as I simply don’t have the time!