Droping 3/2 Truck on MTH Diesel

Hi Mort,

The trucks can be dropped for inspection (not total removal) without removing the shell.  To fully disconnect the wiring you will need to remove the shell.  The truck block is held to the motor with a single screw adjacent the truck pivot point.

It's very uncommon to have a problem with the main worm gear.  The gear is well greased at the factory and will run for hundreds of thousands of scale miles.  Have a look at the idler gears on the side of the truck.  If the previous owner never lubricated the idler gears they can wear on their hubs rather quickly.  Look for an idler gear with a lot of slop.

"Have a look at the idler gears on the side of the truck.  If the previous owner never lubricated the idler gears they can wear on their hubs rather quickly.  Look for an idler gear with a lot of slop."

And also look for debris in the grease. I had someone put my engine down on a scenic area. A little ballast stuck in the gear and stopped the whole engine.

How do you get the motor back in once you allow it to be removed?  Depending on wire routing it is a crap shoot trying to reinstall the motor with shell on.

One thing you can do is remove the wheels by removing the plastic cover as if changing from scale to hi-rail wheels.  This will allow you to independently rotate wheels, examine gears.

As Don states, I have seen a lot of diesel with binding gears caused by debris.  G

Hold the locomotive in its upright position so the worm gear drops down through the frame.  If a wire is caught under the motor mount it's easy to see because the worm won't be perpendicular to the frame.  Slowly lift the truck into alignment with the worm.  As you lift, rotate the wheels so that the worm and spur gears naturally draw the truck and motor assembly together.  Once the motor assembly and truck are pulled together hold the wheels stationary and you can rotate the entire engine upside down and set it in a service cradle.  As long as you prevent the wheels from rotating the motor won't drop down inside the shell.

It's a little bit of a trick and not for the ham handed, but it works reliably.  I don't do it often on Proto 3-2 trucks, although I did earlier this week checking an SD70ACe.  I usually use this method on older engines, such as the PA's and E-units that have the truck side frames screwed on from the top of the truck.  Especially on PA's, the side frames are too tight to change traction tires without removing the side frames.  This method saves the added time of removing the shell on simple jobs.

You are braver than me:-)