Just acquired an old 2343 (Variation C) Santa Fe F3 -- bought as an "untested" unit, so wasn't expecting a lot. But it's in remarkably good -- but very "used" -- condition. Front truck works well, but rear truck won't operate. Pulled the motor -- really a mess from old oil and grease -- and the brass plate over the worm drive din the truck -- possibly the first time it's ever been opened. There is a lot (about 1/8"?) of fore and aft play in the worm shaft powering the wheels. Rolling the truck forward, everything's fine. Rolling it backwards, the gear slides back and binds against the end of the chamber. Pretty sure that's what's keeping it from operating. I read somewhere that I'll have to pull the coupler to free up the aft end of the shaft (the front end of the shaft sits in a small brass cube-shaped block with a single ball bearing in it, but I can't free the shaft and gear assembly. (Also read somewhere that you have to drill out the rivets and pull off the coupler to get to whatever holds the back end of the shaft. That's where I am. Stuck. Anybody have the next steps to stabilizing that shaft? Many thanks.
Welcome to the forum!
Both ends of the worm gear are supported in a bearing with a ball bearing inside it.
You may be able to lift the free end of the shaft out with the one bearing enough to then slide the shaft out of the other bearing without having to remove the coupler retaining plate.
Turn the shaft by hand in both directions and watch the mesh of the worm gear with the worm wheel on the axle. Does it mesh properly? What is the condition of the worm gear on the axle?
Larry
Larry
Thanks for the quick response, Larry. Hope I'm responding correctly.
It's pretty clear that the worm shaft can't be removed by pulling the forward end bearing; the gear wheel on the worm shaft can't move forward enough to release because of the support structure of the truck. (I'd read that the only way is to drill out the rivets and replace them with machine screws and locknuts.) The worm gear shaft aligns properly with the gears on the truck axles, and, when rolled forward by hand, everything works fine. When the truck is rolled to the rear -- toward the coupler end -- the gear wheel on the shaft slides back and binds on the structure supporting the shaft, and the whole assembly self-brakes. So, whatever bearing structure exists in support of the rear (coupler end) bearing has moved or worn out. Can only guess, but your observation that there is another bearing with a ball that supports that end of the shaft is what is creating the problem. Until I've pulled the coupler, I'll be only guessing, but that bearing probably needs to be shimmed forward. Too many unk-unks at the moment. But I'll keep on it.
Thanks for the interest, Larry.
Jack (who used to live near the vestiges of the New York, Westchester and Boston RR -- "The Westchester")