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Worn bearing allows timing to jump a tooth
The OOLS locos use brass bushes for their bearings on the three sets of driving axles. Brass is not the hardest wearing material known to man!
This loco is a club DDE that has clocked up a lot of miles at various roadshow events over the last 10 years or so. At the recent Locomotion event, it was running fine, then suddenly lost power and went all lumpy. Eric was manning the repair bench at the time and diagnosed a worn out brass bush on the centre driving axle which had allowed the bevel gears to jump a tooth which in turn put the timing out. The video below was taken in this state before I did anything to the loco.
Once I had dismantled the loco, I could see that the vast majority of the play was in the brass bush, although there were some fair old wear marksβ¦














Having seen Andrew's picture of the worn crankpins (below), I checked the crankpins more closely while fitting the new coupling rods. Also rather worn:
I managed to steal a fresh pair of crankpins from some spare wheels I'm not using and fitted those to this loco. Should run much more evenly now!
Nick - possibly one for your shop; could you source new crankpins for the centre drivers? Also perhaps the screw/spigots for the front/rear drivers as well. The crankpins are supplied as part of new wheelsets, but it's only the crankpins that are wearing, not the rest of the wheel.