Lionel Legacy diesel replacement motor

Are the gears the same?

Pete

Good question.  I'll have to look tonight.

The motor connections to the circuit board go direct to the motor, just connect to those and ignore the connector for the tach.

gunrunnerjohn posted:

The motor connections to the circuit board go direct to the motor, just connect to those and ignore the connector for the tach.

So these motors are interchangeable?  I’m not sure what you mean by connector for the tach. Do you mean the speed controller?  If so this motor doesn’t have that. It’s on the front motor. 

You stated you wanted to use the motor with the tach PCB for a replacement.  I was just addressing the issue you brought up putting the one with the tach PCB in place of the bare one.  I don't know without seeing them if the worm is compatible.  The motor drive connection on the motor with the tach go to the PCB, and they go directly to the motor terminals. 

Below is a picture of both motors. The one on the left is from the ES44 and the right was from the GP35.  I swapped out the motor and on the bench the rear motor is slow to start turning at slow speeds. The front one starts turning before the rear one.  They both spin at faster speeds. On the track it runs a little choppy at low speeds then smooths out. 

These appear to be Liondrive, no? If so gears are not an issue. They should be identical.

Pete

Tanner111 posted:

 I swapped out the motor and on the bench the rear motor is slow to start turning at slow speeds. The front one starts turning before the rear one.  They both spin at faster speeds. 

The dual motors on legacy diesels do not spin at the same speeds unless under load. 

 I believe the "trailing motor" will always spin slower in an "unloaded " situation like in a cradle.

This is by design of the speed control.

The nice thing about at least *some* of the Legacy diesels, is that the gears are back-drivable.  In other words, the wheels can turn the motor, and therefore the faster motor can "help" the slower one.  Adopting back-drivable gears went a long way toward taming the infamous Odyssey "lurch."  It also improves coasting and the sense of mass when running the train.  BTW, most if not all of Lionel's postwar locos were built this way.

Another nice thing about the LionDrive system is that they all use the RS-385 motor with a horned ball type universal coupling.  So you don't need to find an exact donor motor with a worm gear of the same pitch, diameter, and length.

It will work.  Go for it.  The Liondrive system is a strong system.

After swapping the motors, the engine is not smooth at slow speeds.  It's jumpy.  Something is not right.  I removed the shell and I don't see that anything is rubbing on either motor.  

Did you rotate them through a full rev of the truck wheels to see if there is any binding in the gears?  As others have said, the Liondrive eliminates any issue with gears.  Note that there is a little coupling between the motor and the truck, if you lost that, the motor isn't doing anything.

Ran the engine when I got home. Still jumpy. Removed the shell and made sure nothing was rubbing on the motors. Everything looked fine so put the shell back on.  Didn’t change anything. Maybe something was rubbing and removing shell fixed it. Runs good now. 

sd70ace 6-28333  Rear motor will not start with front motor. replaced with new Lionel motor, did not solve the problem. voltage is the same as the front motor, drive gears and gear box runs free. changed RF board, did not help. New motor controller board?? Front motor runs strong. replace wiring on rear motor. Rear motor acts like its not getting enough amps. any ideas?

Did you read the whole thread?  The motor with the speed control will almost always be turning first if you're running on a bench on rollers or with the wheels free.  The motors are in parallel, you should be able to verify the wiring between the two.

Yes sir...on bench wheels free, rear motor starts after front motor at 1 volt. parallel wiring from front motor circuit board, run speed control up and down... seemed OK.. On track engine preformed pretty good for a few minutes... than at different low, medium, high momentum, rear truck wheels continued to drag or not turn when front truck wheels where spinning to move forward or reverse. rear motor would finally start at a higher velocity, about 4 or 5 volts....Thanks

I'd be looking for a mechanical issue as replacing the motor didn't change anything.  Virtually every dual-motored engine I've seen with speed control has the same setup, two parallel motors and one with speed control.  It works for zillions of them, so something is wrong in your situation.  Time to do some closer looking at the mechanics.