Eagle Racing has started producing some option parts for the R31 based chassis. The option parts available for the OTA-R31 or the TEH-R31 will be, a 39T Delrine front one-way pulley, blue anodized alloy rear spool, blue anodized front one-way tube, and alloy ball differential. These parts will be compatible for any R31 based chassis. Seems that some people have been having trouble with the top end racing front one-way tube malfunctioning, so this would be a much better alternative to the cheap clone parts. These parts are available now so get them while they last.
Eagle Racing Front One-Way Tube
The 39T pulley is included with the one-way tube (In the past, Eagle also provides the bearings and shims with their parts as well)
Eagle Racing Solid Spool Axle
The 39T pulley is included with the solid axle (In the past, Eagle also provides the bearings and shims with their parts as well)
Eagle Racing Ball Differential
The alloy out-drives are made of high quality 7075 aluminum alloy for best durability and performance (In the past, Eagle also provides the bearings and shims with their parts as well)
Eagle Racing 39T Front One-way Delrine Pulley
The 39T replacement pulley is made with a larger center bore for fitting into a Front One-way tube
Source: Eagle Racing Japan