# Do AF Geeps run hot?



## Smoke Stack Lightning (Dec 7, 2015)

I picked up a set of the T&P powered/dummy combo. The engine runs smooth at any speed however I noticed the motorized truck is very hot to the touch. So I tore it apart and cleaned it. I removed the once grease, now earwax from the chassis and cleaned up the gears until they shined. Put quality grease and gear lubricant in, cleaned the commutator, put it all back together and now it won't run. It hums. I've spent over an hour with the set screws trying to center the armature. Armature spins pretty easy, but she just hums. I'm supplying power to the brush springs for lack of a better place. Maybe this is the problem?. Barker's book says apply power at the solder points at the top of each truck, whatever that means. Only one truck is powered. I'm finding out my engines run fine until I fix them

Rich


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## llskis (Apr 11, 2013)

S/S/L: Have not noticed that they run any hotter then other engines. But the one "Hot Spot" is the light bulb that is so close to the number sign board. I lot of Geep bodies have been ruined by the light bulb. The body will melt when close. Remedy: Change to a cooler bulb or try to move the socket away from the body. Larry


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## AmFlyer (Mar 16, 2012)

The bottom of the powered truck on my 370's gets slightly warm, nothing you would notice out of the ordinary.


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## Smoke Stack Lightning (Dec 7, 2015)

Okay, I'll keep searching for a cure. Thanks for the tip on the bulbs. Oddly enough, I've seen ads for AF Geeps that actually say "no melt spots" as if this or bulbs might be a common problem. I've heard that the axle chase openings may be worn oval causing the axle to bind resulting in a hot motor. That is supposedly a common problem that requires rebushing or holes be drill pressed and axle bushings added.

Rich


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## flyernut (Oct 31, 2010)

Always run a cooler bulb in anything you own...


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## AmFlyer (Mar 16, 2012)

Here are some observations and opinions on my part. The 3 372's and 2 364's i have all run fine with no overheating I repaired one of the 370's and one of the 364's. All the diesels will get warm to the touch. In my opinion they are a real pain to get running correctly after disassembly. replacing brushes correctly is tricky as is proper spring tension adjustment. Then the two screws positioning the motor field need to be set. All this is an iterative process that takes me a lot of time to get just right.
None of these engines noted above have traction tires. With the traction tire equipped single motor diesels the engine can run much hotter because a heavier load (more cars) can be pulled without the wheels slipping. I suspect many of these engines were overheated this way by the kids who got these as presents. I do not usually use the knuckle coupler diesels on my layout. Were I going to run them all the time I would do a can motor and electronic reverse unit conversion. The engine you have can be made to run well but I find it to be tricky and time consuming to get everything adjusted just right. It also sounds like your reverse unit fingers may not be making good contact with the drum and the chassis may need to be rebushed. Never put power across the brushes, these are series motors so the field and armature windings must always be connected in series to the power supply . Some engines have light bulb damage, but by no means all. To get bulb damage on the plastic body that indicates to me the engine was run for long periods of time at full transformer voltage, a sign of overloading or lack of motor maintenance. Mine will not make it around the curves above 12volts.


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## Smoke Stack Lightning (Dec 7, 2015)

I can't figure where to run the test power to with the shell off and off track. Probably a dumb question, but where? Somewhere on the reverse unit?

and... when you say cooler bulb, would that be minimum of 18V or even higher voltage. Is a screw in LED available anywhere?

Thanks,
Rich


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## AmFlyer (Mar 16, 2012)

For testing with the shell off you should be able to touch the two power leads to the wire solder joints where the two trucks are attached to the chassis.
Regarding the lights. check the transformer output voltage at the setting normally used to run the engine with train cars attached. Mine is 10 to 12V for a relatively fast speed so a 14V bulb is fine. If the voltage is above 14V then I would recommend you put in a 24V replacement bulb. they are readily available from parts suppliers.


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## Smoke Stack Lightning (Dec 7, 2015)

Wow. All that hassle because I had the power supply hooked up to the brushes. No wonder it just hummed! Believe it or not, I had the motor running this way but not very fast and it heated up. I'm electronically challenged. Hooked it up like you said Tom and it ran fine. Put it all back together and its running smooth as silk both directions. Had it running a half hour and motor truck is only slightly warm. I read in Tom Barker's book where the 68 ohm resistor for the horn is what melts the shells. As he recommends, I cut one of the leads and left it there for looks. Obviously a bulb to close to the shell would also. I stopped at my LHS for some 24V LED screw in replacement lamps, but they won't work unless the engine is rocket speed. I put the original bulbs back in but there is no indication of the volts, they only have 1449 stamped on them.

Until my next problem my friends (which probably won't be long!).
Rich


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## AmFlyer (Mar 16, 2012)

A 1449 is a 14V incandescent bulb, it replaces the old Gilbert number 440. That is the correct bulb for the engine. I apologize for the LED confusion. I meant a 2449 replacement incandescent if there was concern about high heat. The 18V equivalent replacement is a 1447. It sounds like your engine is now running great and the 1449 should be fine. The LED replacement is more complicated for transformer operation. It always feels great when the engine is back together and running perfectly!


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