Lionel Trackmobile Problem

Mark: Just a thought as I don't own a Trackmobile; does the unit have  a traction tire installed? If so, is it rubbing on anything on the chassis structure?

I say this because I just spent this past week grinding brake shoes to fit on my Wabash &  L&N F3 power units. It seems the latest vendor changed the side frames and didn't leave enough operating clearance in consonance with some over sized traction tires. They ran just like you described until I ground down the inner brake shoe on the side-frames.

I can tell you that the Trackmobile is a PITA to take apart, I had to disassemble mine to put the windows back in.  This doesn't sound like traction tires to me, and it's pretty easy to see if they're hitting.

 

The drive on that unit is pretty simple, there's a horizontal motor with a worm gear on each end that engages the axle gear.  So, if something is jamming, it's right in that area.

 

Here's the Lionel Trackmobile Parts Page where you can see what's inside the little bugger.

I haven't felt brave enough (Or had the need.) to take my TrackMobile apart yet, but there are 4 screws on the central section of the underside which look as though they should allow access to the mechanism. 

 

Looking at the parts diagram, there are a lot of small parts packed inside here, so be very careful if you do open it up.

 

Have you tried running it in the opposite direction? If something has managed to get caught up in the works, this might throw it back out again.

 

As these locomotives don't have traction tires, these should not be a problem.

Thanks for the reply.  I checked and it does not appear to have traction wheels and there is no interference around the wheel area.  Thanks for the parts breakout.  I have tarted to disassemble but can not figure out how to get to the motor and gear area deep inside.  It is not obvious how to get that last step.  Any tricks and tips are appreciated.

When the problem first started it was only in reverse.  Now it happens in both directions, sometimes it will go 6 inches forward, then one inch reverse, then barely move in forward again.  It does sound like something is caught up inside catching the gear or axle.  Just have not been able to figure out how to get deep enough to see it.

It could be the motor.  I just replaced a couple of motors that developed a bad winding or connection internally.  They'd run, sort of.  Does it feel like something is actually stuck in the gears?

When it stops it sounds like the motor is humming but is not turning. If it does move it has hard clunks and jerks along the track like something is stuck in a gear

Could be there is slippage between the worm gear and the motor axle it is mounted on. The humming I am guessing is from a freely spinning motor and the jerky movement is probably the result of the gear one minute sticking tot he axle properly and another moment disengaging completely. My 2 cents. You won't know for sure till you have full access to the drive mechanism

Thanks.  That makes sense.  I will try to figure out how to disassemble it enough to get to the axles and motor assembly and take a closer look.

Whatever it is, it's in the bottom end, that's where all the moving parts are.

 

Finally figured out how to get into the drive line.  Motor runs fine in both directions when disconnected from the gears.  I found two inter gears serving the front axle that had a missing tooth on each gear.  I ordered replacement gears.  I suspect that will take care of it.  Thanks for your help.  

WOW, I wonder how that happened???

My guess is the gears had some defective teeth or weak teeth or just defective from the start.  Maybe when they were originally assembled there was something in with the gear teeth that finally broke them.  Total running time is probably 15 minutes at most.  Either way glad the problem was identified.  Thanks again