It is an interesting point regarding axle wear on the early Lionel diesel chassis. They do use a bushing but it is a bit tishy and not designed for purpose.
The width of the chassis that the journal runs in is basically 4mm in width. The bushing that Lionel use are 2mm in width. It is just a push fit in and stops at the point where the chassis has not been machined through. Then there is the bizarre statement that on the end of the box it says the engine has wide axle bushings. What this means is that they they are advertising that the bushings are part worn out before you use it. The truth is that the axle journals are 4.05mm each side, but the knurled centre part where the gear fits measures out at 4.35mm. So to assemble the axle and gear with the bearings already in place the bore has to be larger than the knurled measurement. Why advertise that the chassis is already worn before you get it always puzzled me, I would have kept quite on that one.
i have had a need to rebuild a couple of these and I fit the chassis with full width bearings and take them out to 4.10mm. I then mark one bearing, tap it out and then fit the axle and gear and then slide the bush over the axle and tap it back to the same position it came out. Doubled my bearing surface and have only 0.05mm clearance. Why Lionel couldn’t have done that beats me.
