As found on service sheets 297C & 326B for R9524, 1 wheel on each axle has a traction tyre fitted.
Hornby X9426M GWR / BR Diesel Railcar Drive Unit Wheel Set
Hornby Genuine Spares X9862 Class 43 HST 125 Drive Unit Wheels & Axles Set NEW
Hornby X9429 GWR / BR Diesel Railcar Round Buffers Plastic (Pk4)
Hornby X9427 GWR / BR Diesel Railcar Bogie Frame
Hornby X9817 Underframe / Chassis For GWR / BR Diesel Railcar
Hornby X9431 Dummy Bogie Complete For GWR / BR Diesel Railcar
