for mine i used a bearing from a shimano bottom bracket from a bike, i would be careful about any claim's about performance upgrade,s on my td5 it felt like giving an asthmatic an inhaler and now it doesnt feel like your pushing it on to maintain 70-80 mph a bit like overdrive but it does feel less torqey low down but just when moving away once it's rolling it's superb, once out of warranty it will be consigned to the skip after being beaten senceless by a big hammer, despiseable thing !!!!!!