Or a DZ126T.

The DCC tenders you are looking at are mostly useless with your standard 4-4-0.  You can not connect the new tender to the old locomotive without extensive work.  The new tenders contain wiring and circuit boards such as a decoder and speaker, but no motor.  A motor will not fit in the new tender without first eliminating Bachmann's electronics.

You will not be able to program the turnouts if your track geometry has created a short circuit.

The old-time 4-4-0 is seven inches without the rear coupler.

Yes, I have searched the Bachmann site and the Internet in general.  All I found was references to the axles in question being longer or shorter than other axles, etc. - but no actual length data.

What are the axle lengths of Bachmann's HO scale #42903 and #42904 wheelsets?

If you added a graduated pier set to elevate the track, your grade changes may be too extreme.  This can cause couplers to slip past their gathering area.  Also, the trip pin of a car on level track can dig into the ties as it approaches the start of a steep incline.

Code 100 is a rail size.
Code 110 is a wheel tread size.

What is the origin of that trailing truck?  I see it described as a Delta, but the shape of it does not look like any I recall seeing on a North American locomotive.

The car length is about 165mm including the end platforms and excluding the couplers.  Weight is 3.5oz.

How does one determine the appropriate size (amp) power pack/transformer/controller/command station based on the feet of track?

There are two tabs under the floor directly under the doors.  Push the tab towards the opposite end of the car (horizontal direction) while gently pulling the end platform away from the body (vertical direction).

Quote from: KEVIN296 on February 19, 2015, 06:29:22 PM
how do you open the 1800s coach car and combine to put liting in

OP provided the part number for the track piece in question: 44440 is a Crossing w/Steel Rail & Black Roadbed - E-Z Track(R) -- 30-Degree.

The crossing may be defective.  Temporarily replacing the crossing with a couple pieces of straight track (don't try to run your train with this track configuration - just apply power to the track to see if the power pack goes into overload) can help you determine if the crossing is bad or if there is a short circuit elsewhere in the track.

A crossing can also be tested by disconnecting it from the other tracks and using an ohmmeter or a light bulb (12v bulb if using your train power for testing or 1.5v bulb if using a battery for testing).  Electrically, the crossing should be like two pieces of straight track.  No power should flow from any part of one straight track to the other.

No DC voltage on the track with no trains on the track, and no AC voltage at the accessory terminals would indicate either a bad transformer or a bad speed controller.  You tested this with a voltmeter on the appropriate settings - right?

If you are going to test a locomotive by touching the wheels with a 9v battery you need to make sure you are applying power to those wheels which actually conduct electricity to the motor.  On Bachmann's old time 4-4-0 the motor gets power from four wheels on the tender (one truck is insulated on the right side the other is insulated on the left) and only one of the four drivers.  The headlight gets power from two wheels on the front truck and one driver.  The motor and headlight are different circuits - power to one does not indicate the other is getting power.

IIRC, Bachmann item number 736 has been on the market for less than a year.

Your terminology, which seems to match Rivarossi's terminology, vs. the terminology others are used to may be causing some confusion.

When you refer to the front truck, most people are going to think you are talking about the four wheel lead/pilot truck (part #78).

Based on the part numbers you provided (#54 & #55), it seems your challenge is determining how to attach the eight wheel front engine (cylinders, side rods and drivers) which Rivarossi unfortunately chose to also call a truck.

I have not disassembled or reassembled one of these locomotives myself so the following is my best interpretation of Rivarossi's diagram.  It looks like #54 is inserted horizontally through #31 and #55.  Since #54 is called a screw, one of the two holes in either #31 or #55 should be threaded.