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Reply to "Changing the tires on a JLC UP Challenger"

There's no quartering involved in removing the rods!  Quartering in the relationship between the left and drivers on a single axle, and it would only be altered by pulling a wheel off the axle!

Not hard at all.  The tries are on the rear axle of each power truck.  You just have to remove the one screw and note where the spacers are, pictures are useful.

The one point of caution is getting the eccentric crank back on the wheel in the correct orientation, it fit into the wheel notches in four different places.  Again, take a picture before you disassemble it, and make it match the picture.  FYI, the eccentric crank should point inward near the axle.  It's possible to put the eccentric on in any of four orientations, see below.  The green arrow is the correct orientation, note it points close to the axle.  The other orientations indicated by the red arrows are the wrong way and will result in lockups.

Click graphic to enlarge


I’ve revised my note to more clearly reflect we are essentially warning against the same potential disaster outcome here common to a non-repair person on locomotives like this one.

Easy as this may be for me and for you, I stand by my recommendation to the OP as what’s in his best interest for this particular model based on what he wrote.

If this was a Vision or 2019 Big Boy, I’d say go for it. Even the JLC Big Boy had an odd configuration with the rear driver set that makes it a tricky one to do tires on. If I remember right - the front most wheels on the rear driver set are slotted, but not the rearmost wheels like later models (which is much easier). The drive rod guide gets in the way of that one.

Last edited by DdotCdot
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