Bad Overland drives, total write-offs?

[riogrande491]

For reference I found a couple of photos on my computer showing a representative of the type of Overland drive that suffers from axle gearbox lock-ups. This particular unit has not (yet?) Two that suffer axle lockups are in a GP30 and a friend's Alco C430.

First up, an example of what I'm calling a "low slung" 8413 drive, this example in an Alco C425. It is a simple "documentation" shot taken for a different purpose during a decoder pre-install.



The aluminum tube drive shafts. The brass collar with set screw is far better than the acetyl (?) collars that can't hold a set screw without stripping out.



A representative 2-axle truck. These were only 2 wheel pickup, to which I added a bit of PC board and a phosphor bronze wire for all-wheel.



Again, the point of these photos is not to show off my work but rather to establish the type of Overland drive in which I've experienced axle gearbox lock-ups.

[sarge]

I very much liked the NYC version C430; big bad handsome model once painted a good gloss black as they were.

One serious flaw in any that crossed my bench (three or four of them, and I wish now I had kept one) was the shafts not long enough to protrude all the way through the brass or bronze bearings. They just stuck halfway into the brasses. Too short, and unlubricated for just the briefest period they would eat into the bearing for lack of surface area, then bind when the shafts should normally be thrusting through.

Check for that case. Otherwise, I'll stick quietly by the earlier comments until more info becomes known.

[bob turner]

Reluctant to reply, since that puts my name on the last four threads as the final poster. You would think I have nothing better to do . . .

Those U joints are CLW, and designed for a cotter key through the steel shaft. The early Overland U joints couldn't make it off the showroom floor.

Any manufacturer who would supply an 8413 motor is a manufacturer who does not care about operational components. Going to an 8423 at the time would have added maybe two bucks to the price, and alnost doubled the performance (assuming decent gears and U joints).

[Wolf]

Bob---
If I were you, I would not worry about being the final poster on four threads.
You are, at least, providing input, and not just lurking in the background!
We all know that you do have other things that you do at least occasionally

And there! You are the final poster on only three threads now...

[riogrande491]

Curiously, so far I've experienced no issues directly attributable to Pittman 8413 motors in many of my Overland diesels (GP30s, GP40, many Alcos). Mine run extremely well and with smooth starts with the NCE 408 and even better with a Loksound V4L DCC decoder. The dual flywheels are a bonus, as is the lower motor mount which makes more room in the car body for electronics.

The only problems I've encountered with my Overland drives were axle gearbox lockup, stripping of acetyl universal set screws attached to the end gearbox towers, and to-be-avoided worn out tank drive vertical gearboxes. Engines with aluminum drive shafts can be noisy with a sound as if the drive shaft is flopping around in the free-play of the universals.

That said, many car body solder joints including internal structural members failed, but that's a different problem. I'm getting better at internal resistance re-soldering without damaging the paint.

"Your mileage may vary..."