TMCC diesel engine jerking when going forward... Reset and no better.

Do any of the lights flicker when it jerks?  I have a newer Legacy GP38 that does something very similar but the number boards will flicker at the same time the engine jerks. My issue is due to a power loss through the rails but it is so brief and only occurs at very slow speeds.

@H1000 posted:

Do any of the lights flicker when it jerks?

They do not.

Does the voltage fluctuate in this section of track when running this engine? And are both outside rails well grounded?

It's possible that one of the motors is loose in it's mount. That could make it run OK in one direction, but jerky in the other direction.

I’d check what Roy has brought up. Check for a loose motor.

@RoyBoy posted:

It's possible that one of the motors is loose in it's mount. That could make it run OK in one direction, but jerky in the other direction.

I'll pop the hood and take a look today.

Quick video of what's happening.

https://www.youtube.com/watch?v=QEsPdubojkA

As mentioned above and perhaps a traction tire or part of it binding on a wheel.

Definitely looks like something is binding when it comes out of that turn. If you look closely you can see the frame twist just a bit like one motor is pushing or pulling the other. How does it run off the track, do both motors turn evenly & smoothly?

I would add a power feeder wire to the section of track where it is doing.  Ive had similar issues and it wasn't getting enough power, even if you have transformer at full power.  In my experience TMCC engines need more power feeders  to run better. Also I would have a power drop between switches.  I don't think TMCC engines pickup enough power between switches without a feeder being present.

Spent some time today and by hand the motors and gears move smoothly by hand. That curve mentioned is 12" from the transformer, power shouldn't be a problem. I was PM'd about armature play in the motors. Could be the issue, unfortunately replacements are currently unavailable.

Play in the armature shaft could be the basic issue. if the flywheel lifts up too far, the tach sensor starts missing pulses.

When I had this same issue on my MTH subway set, it turned out to be a broken gear in the drive train.  A single tooth on one of the small gears had broken off. Not cleanly right at the base, but about one half of the side of the tip.  Thus in one direction there was enough metal to engage the other gear, but in the the opposite direction there was a void and the broken tooth wouldn't engage until the unit had been forced further ahead by the second motor.  Everything moved smoothly by hand on it too, only a visual inspection found it.

Does it also do it in conventional or just command.

@Kevin1 posted:

Does it also do it in conventional or just command.

Lurches either way, Odyssey on or off in Legacy. Tomorrow I'm going so set a small loop, no binder clips at the connections and give that a whirl. Finally, both motors appear to be acting the same. Thanks for the input!

Some simple stuff, before you tear it apart.

1. Wheels need to be clean, spot-less.

2. Same for the third rail pick-up contact.  A light oil-ing of the contact roller may help.

3.  Trucks with side gear assemblies, can pick debris, from the rails.

4. Track continuity.   Track joints can loosen over time.

5.  Track needs to be clean, top of rail.

Now you can tear it apart. 

@Mike CT posted:

Some simple stuff, before you tear it apart.

1. Wheels need to be clean, spot-less.

2. Same for the third rail pick-up contact.  A light oil-ing of the contact roller may help.

3.  Trucks with side gear assemblies, can pick debris, from the rails.

4. Track continuity.   Track joints can loosen over time.

5.  Track needs to be clean, top of rail.

Now you can tear it apart.

Thanks Mike, did all those before I posted!

I'm still thinking it's end-play in the armature of the Odyssey equipped motor.

@gunrunnerjohn posted:

I'm still thinking it's end-play in the armature of the Odyssey equipped motor.

.016 one motor, .021 motor with odyessy

Can you use something to just lightly press down on the end of the shaft of the odyssey motor as it runs and see if it smooths out the running?  I'd probably look for something "dished" so it'll just stay on the tip of the shaft.  A common nail set for larger nails has a nice dish shape.  At a slower speed it should be easy to keep it on the motor shaft and see if the jerkiness stops.

Test 1

Complete new small loop. Ran in Legacy, Legacy with Odyssey off and in conventional. No change in engine operation.

Test 2

Ran holding a small nail set trying to keep Odyssey flywheel from moving up and down, no change.

A sight for sore eyes. Me, my wife and my daughter all laying on the floor watching the flywheel on the motor. All three of us confirmed the movement is more of a bounce than a gradual rise and fall.

Time to dig a little deeper. Thanks for all your help so far!!

When in conventional, speed control was off correct, and it was acting the same way.  Also before it was only doing at one section of the track, now it is doing it all the time? .  I thought it was a power or command issue but since its doing it on another track and in conventional it seems to be mechanical. Hopefully more  suggestions come in.

Got it on my roller base this morning. Certainly one motor acting up...

https://www.youtube.com/watch?v=dVsas7p0QNI

Well, I'd be looking very closely at the trucks and any binding or crap in the gears.

You can remove the motor from the truck and test it again to see if the motor calms down when it doesn't have anything connected to it.  If the motor out of the truck turns free, then I'd be looking at the sensor and magnet ring.

@Kevin1 posted:

When in conventional, speed control was off correct, and it was acting the same way.  Also before it was only doing at one section of the track, now it is doing it all the time? .  I thought it was a power or command issue but since its doing it on another track and in conventional it seems to be mechanical. Hopefully more  suggestions come in.

I don't think speed control is off in conventional. Later versions of odyssey offered a switch to turn it off but otherwise it is always on. Is the magnet on top of the motor intact? They have been known to break apart.

@iguanaman3 posted:

Is the magnet on top of the motor intact? They have been known to break apart.

Yes, one piece. I had a TMCC engine where one broke while operating. Accelerated pretty quickly!!

You may also want to look at the clearance between the flywheel and the sensor board.  You will want them close, but not touching.  Again, as John has mentioned, check for movement of the motor shaft.  In one direction, the motor shaft will rise and in the other direction, the wheel gear drag will pull the motor shaft down.

Well, it's clearly got to be the motor, truck, or encoder I would imagine.

Any tips on getting this motor out???

Jeff,

If I recall there are screw(s) in the trucks that have to be removed. Then there is a mounting bracket attached to bottom of the motor.  The screws that hold this bracket in-place might be really hard to remove from the motor itself.  They tend to "gall" together.    It's not the easiest motor to remove.

Is your goal to replace the motor?

Were you able to confirm there is enough clearance between the flywheel and the odyssey pick-up board?  If the flywheel needs to be moved on the shaft, there are options you may want to consider.  Be careful not to damage the magnetic ring.

JEFF,

  Here is Lionel’s exploded view of the parts that might help.  Good luck.

https://www.lionelsupport.com/...amp;CFTOKEN=27471020

@DaveGG posted:

Jeff,

If I recall there are screw(s) in the trucks that have to be removed. Then there is a mounting bracket attached to bottom of the motor.  The screws that hold this bracket in-place might be really hard to remove from the motor itself.  They tend to "gall" together.    It's not the easiest motor to remove.

Is your goal to replace the motor?

Were you able to confirm there is enough clearance between the flywheel and the odyssey pick-up board?  If the flywheel needs to be moved on the shaft, there are options you may want to consider.  Be careful not to damage the magnetic ring.

There are plastic insulators under the pick-up rollers. The screws are under them. They are not easy to pop out. Goal - Pull the motor out, run it, inspect all the gears. There is clearance between the flywheel and the pick up board. Enough?? Business card gap?

@laz1957 posted:

JEFF,

  Here is Lionel’s exploded view of the parts that might help.  Good luck.

https://www.lionelsupport.com/...amp;CFTOKEN=27471020

Thanks, I've pulled that up several times!!

You have to take the pickups off to get the trucks off.  That truck design is straight from the devil!

@gunrunnerjohn posted:

You have to take the pickups off to get the trucks off.  That truck design is straight from the devil!

Pick ups are off, those plastic insulators under the pick ups are a royal pain... And I'm trying NOT to break them.

Back on this one this morning... Finally removed the motor from the trucks, what a PITA. If you ever run across one of these... Once you remove the pickup rollers there are plastic pieces they sit on called insulators. In those insulators is a small metal piece.  There is a VERY small screw from the top that needs to be removed on each insulator. Once those are removed the motor releases from the truck...

I powered up the engine and that motor still sputtered even with it out of the truck. I guess I can safely say its bad. Time for a new motor and one insulator...

I just wrestled with one of those trucks this morning, I was replacing a broken electrocoupler.  What should have been a ten minute max job turned into more like 45 minutes!  As soon as the bottom of the truck comes off, the wheels and internal gear falls out!   Getting all of those lined up and the flats on the bottom of the bearings all aligned is a neat trick.

The person at Lionel that designed these trucks should be drawn and quartered!

What really stinks is Lionel lists the motor as "Unavailable"... So a real nice set is basically shot. Argh...

That sucks. Not a solution, but can this be run with just one powered truck?

Mark in Oregon 🎄