if it's the joints on the end of the shafts,these always seem to go,then you can get them new from Woodford garage.
These will cost about 45 pound!
I bought a XR4x4 drivers shaft from a scrapyard for $25 and used the bearing on that one,and you get the other bearing and shaft as a spare!
Be very carefull with these bearings as these are very fragile.
If you need info on fitting post up here!
Dave.