Maintaining Older Con-Cor Passenger Diesels in N-scale

[Desertdweller]

This thread refers to the Con--Cor passenger units produced by Kato.  At the time of their introduction in the late Sixties, they were state-of the art, and if properly maintained are still good units.

I didn't know whether this thread belonged in the N-scale forum, or in the "Old Timers Reminiscing" thread of the General Forum.  But since there are doubtless still a lot of these running on N-scale railroads, I'll put it here.

The chassis was originally used in the PA-1 and PB-1 models.  Later, it was lengthened and used in E units and DL 109 and 110 units.  Except for the length of he frame and driveshafts, and the style of truck sideframes, they are alike.

The frame design is a little different than most split-frame designs.  It is made of three milled metal pieces, with a molded plastic separator between the one-piece upper frame, and the split, insulated lower frame.  The open-frame motor rides inside the upper frame, with motor brush contacts that pass outside the plastic separator to contact each half of the lower frame.

Like all split-frame arrangements, it is tricky to reassemble, but not as much as most are.

Last night, I took apart and tuned up a UP E-7 that had been a sluggish performer since I bought it new in the mid- 1980"s.  Now it runs as fast and smooth as my Life-Like UP E-7.  In fact, I can run them as a pair on my DC-only railroad.  Tonight I did the same with a pair of 30 year-old UP PA-1's.

After removing the body shell (watch out for the fuel tank, it will come free when you pry off the body) you will find the main frame is held together by four screws that pass vertically through the upper frame, separator, and into the lower frame halves.  Two of these screws pass through plastic insulating tubes-don't forget where these go!

Take these four screws out and everything will come apart except for the truck assemblies.  Those are held together by four screws each the come up through the bottom of the truck.  Eack truck is held between the lower frame halves by little ears (like on a Bachmann).  When the lower frame halves separate, the trucks will fall loose.

The upper frame will remain attached to one of the lower halves by a headlight wire containing a diode.  This wire is screwed to the lower frame half.  You don't have to disconnect it if you are careful how you handle the parts.

Gently spread the motor brush contact strips and the plastic separator will come free.  Note their is a ridge molded on the lower side of the plastic piece.  This serves to locate and separate the lower frame halves.

You will see what looks like a flywheel on the end of each driveshaft.  These are not flywheels, they are actually hollow drums with gear teeth on the inside that engage pinion gears on each end of the motor shaft.
After thirty years of use, I figured it wouldn't hurt to carefully oil the motor shaft bearings.  The key here is to not over-oil, or the oil may migrate onto the commutator and brushes.  I oiled it with WD40.  I sprayed some into an old pill bottle, and dipped a number 11 X-Acto Knife blade into the oil, and touched the blade to the motor shaft on the outside of the motor frame.

The drive shafts are supported by brass (Oillite?) bearings in plastic pillow blocks.  They locate on little ridges in the upper frame.  I did not oil these, but made sure they were clean.

On these old units, often problem is caused by fiber buildup on the brass worms.  Holding these carefully to keep the parts in place on the shaft, I cleaned each brass worm using a new brass brush chucked in a variable-speed Dremel Moto-Tool.  Use the lowest speed possible, and wipe away the loosened fuzz with a rag or paper towel.  You can then lightly grease the worms with LaBelle 106 Teflon grease.

The trucks get crudded up in use.  Take out the four bolts and they will come apart.  The center and outer axles are powered on each truck, and all wheels pick up power.  The wheels are insulated by using plastic axles running in brass bearings.  With the trucks off, you can clean the wheels with the Dremel brush before you disassemble them.

The axle gears are powered by a worm gear that rotates on a fixed shaft molded into one half of the truck frame.  Pull this gear off and clean it up (by hand only).

There will be at least one copper contact piece on each trucks that wipes the backs of the drive wheels.  These eventually wear out and can cause drag.  It is not needed to transmit power if the metal components are kept clean.

These units use a system that goes back to Lionel F-3's.  The pilot and front coupler are attached to the truck, not the body.  This does not look so good on curves, but it does keep the coupler lined up with the one on the following car.  Micro-Trains makes a conversion for these, but I used a regular Micro-Trains coupler with the adapter (the little metal box) installed in the stock coupler pocket.  On one of my PA's. I had to grind away part of the top of this pocket to get correct coupler height.  This pocket is held in place by the truck sideframe piece pressing against the pilot from below, so this can be a handful to reassemble, probably the hardest part of the job.

These are well-made, durable locomotives.  They can be adapted to DCC by milling a clearance atop the frame.  I expect mine to run another 30 years, although I don't expect to last that long personally.

Les