Geep 374 hot truck.

Hi Smoke stack Lightnin,

I do believe you should tighten those set screws so the field is held down and centered around the armature. A brand new unit will have those set screws just snugged down but as those units wear a little more pressure is required.

The whole problem stems around the axle holes wear oval with the electricity conducted through the wheels will cause the action of eroding the metal away and the gears grind and force the amateur to bind against the field and cause the heat you are feeling after running a short time. The chase needs to be re-bushed or a new one purchased. Since the latter is no longer available you would have to re-bush yours. This is not an easy task but there are people that can do it for you for a price. Look in the S Gaugian magazine and there are some of those people who can do this for you.

I am sorry to be the barrer of bad news but I have several of this type of American Flyer diesels in my possession, but some I adjusted as you have and just run them for a short time others I have re-bushed my self with some success but not always.

The new Lionel-Flyer diesels are a little better but some times have different problems. I have purchased many of them  and usually run those. American Models Manufactures a great line of the diesels witch I have purchased also and they run superbly all the time.

Take care, Merry Christmas and Happy New Year.

Don

First off , you stated that you applied power to the brushes . You can't do that . Put power to one brush & one field lead & jumper the other brush to the other field lead. Go to PortLines Hobbies & look for wiring diagrams.

Back in the 50's even when new the Flyer diesel trucks will run hot after several minutes of running.  I could always run the steam locos longer than the diesels and some steam locos barely got warm. The diesels always got hot. Note these were new in the 50's and didn't suffer from the enlarged axle holes and were properly lubricated, they still ran hot.  IMHO it is a design issue.

These units do always run on the warm side, these are ac open frame motors and the chassis is part of the motor.

Ray

I know the seller has a large business and actually had advertised this diesel having "no shell melt marks" so it does seem that there is something commonly inherent with the Geeps. From what I can see the axle opening look pretty round. I guess I this point I may as well pull a wheel to be certain. Don, thanks for the detailed explanation. I don't have a drill press so I'll check the S-Gaugian website for services.

Rich

Smoke Stack,

Call Robert Barth in Perryopolis. I believe he could install new bushings in your diesel truck. His phone number is 724-736-0488.

Rich,

You don't necessarily need to pull a wheel.  Just rock the wheel/axle assembly up and down and then side to side.  Compare the tolerances.  If it seems a lot more in the up and down motion, you probably have worn bushings.  Also see how the axle gear meshes with the worm gear on the motor.  With the wheel/axle assembly all the way up towards the worm gear, there should be a bit of play in the motor's shaft.  If there is none, and the motor shaft moves up a bit , you have worn holes.  The excess strain on the motor's worm gear means the motor is working harder than it should.  Re-bushing is the only way to cure it.  However, as stated by others, these diesels tended to run hotter than the steamers. 

I believe the trouble started with Gilbert.  They had and "oil" with arrows stamped in the truck side frame assembly, and it didn't point to the place that actually needed lubrication the most.  I remember as a kid oiling the heck out of the thing, and never once oiled the axles themselves.  Years later, the Silver Rocket quit running.  By the way, the locomotive has sliding electrical pick up shoes, so the power isn't all run through the wheels.  Less arcing at the axles.  It still wore the holes.  Eventually, I installed brass bushings and it runs much better.  But these two motor units always were temperamental when they got older.  Sort of like some of us... 

The comment about the shell is in reference to the threat of the bulbs being too close to the shell and the heat from the bulb melting the shell, a somewhat common occurrence. Doug peck sells LED bulbs that can be used as replacements as they run cooler. Jerry is spot on about the axle motion and one that is worn but still runs noisily will have a lot of play in it. The set screws are usually set equally to center the armature in  the field.

Rich

Hi Again Smoke Stack Lightnin,

     I have found that from my factory original American Flyer, Chrome, Rocket Set that the bulb in the engine and most diesels was the #1447 - 18 volt bulb. These created less heat generated because of most of the American Flyer Transformers put out 7-15 Volts for operation and longer lasting bulbs in all the plastic engines. Now the die-cast metal engines were the #1449 -14 volt bulbs which could run brighter and had shorter life but hotter. In the engines I bought Used that had bulb damage there were #1449 - 14 volt bulbs. Check yours out and see what you have.

     The other matter I forgot to mention about the diesels were the use of Oil Light bearings used on the armature shafts. These bearings should have been oiled often by the Oil wicks located below the bearings through the side frame bracket. If these were not oiled the oil light bearings could become scored from heat and loose their oil light absorption and there fore never oil the armature shaft and create more heat. On the early Diesels the chassis had oil light bearings also for the axles but of coarse cost effective measures caused the elimination of them in the future. Lubrication is mandatory maintenance measure for all of our model railroad engines. This mandatory maintenance  process will greatly increase the longevity of our equipment and in turn give us more pleasure running our railroads.

     If there is any more needs feel free to contact me again. Happy restoring and running of your equipment.

     Take care and Happy Railroading is S Gauge.

Don

Thanks again for the responses guys. I need to learn about series motors! I had the power supply hooked directly to the brushes, therefore the hum and heat. I did get the engine to run once I figured out to run  one power lead to each of the black truck leads, which on a 3R engine would cause a direct short. The engine runs pretty smooth in both direction. I've run it a few times for an hour or two. The motorized truck is uncomfortable to lay a finger lengthwise on it, but not as hot as an iron that would cause a burn. The shell is warm, but not warm enough to cause any deformities or warping. I do need to replace the bulbs as they are all 14 volt. I read where the 68 Ohm horn resistor caused a lot of shell damage also due to heat, so I cut one end. I also found out that the 2 tiny square parts that were at the bottom of the degreaser pan are thrust plates to be placed at each end of the worm drive shaft. These prevent the shaft ends from wearing holes in the chassis. Hey Jim, Bob does all my work, heck of a good guy and lives close by. Just didn't think (or notice) he had a machine shop or drill press. I tend to think of him more as an electronic genius. Yes Don, good advice on keeping tabs on lubrication. Good to know! Thanks all for your willingness to help, as a new flyer fan I need it!

Merry Christmas All,

Rich