I got a old athearn U engine from back then. good runner but bad side about these old engines is a lot of carbon biulds up on the motor when running over and over and over. get bras 40 in wheels from the protpower west company and the motor wont get too much carbon and wont spark as much.
As long as the wheels are slipping instead of the motor bogging down, it doesn't sound like weak magnets. The only Athearn blue box unit with a super power weight was the F7, so the U28 would benefit from some extra lead in the shell. A tuneup on an old unit like that never hurts either.
http://www.hoseeker.org/assemblyexplosionAthearn/Assembly%20Explosion%20Athearn%20U28%2030%2033B%201975.jpg
Nelson
Ex-Southern 385 Being Hoisted
Athearn geared diesels aren't usually fast enough to fly off the rails, but the older ones aren't sluggish either. I've had a couple where the brush springs settled and weren't putting any tension on the brushes. Stretching the springs until they stuck out about 1/4" (at the most) and adding oil to the bearings got them running like new.
Anything without tires will never have as much brute traction as something with. A typical Athearn diesel (like the U28B) will pull from 20 to maybe 40 very free rolling cars, depending on the weight of the engine and the number of axles. There is plenty of room in most of them for more weight, if you want more traction.
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stubbsO It doesn't pull as hard as my other locos ... are these older units just not as quick powered as other loco's or what ... this just goes at a moderate pace. ...
It doesn't pull as hard as my other locos ... are these older units just not as quick powered as other loco's or what ... this just goes at a moderate pace. ...
Ordinarily the sintered metal that Athearn used for the wheels should provide very good traction w/o traction tires. And while they were not speed demons compared to some, the Model Railroader review of the Athearn U30B (which I think used the very same drive mechanism) in March 1972 page 28 recorded a top speed of 150 scale mph. It also said it could pull 30 cars which is not bad.
Two thoughts. First the review said "be sure to seat the plastic worm-shaft housings properly. If misaligned they can bind the shaft and greatly increase the load on the motor" -- if you have that problem that would account both for poor pulling and slow speed.
The other possibility is that the motor magnet is weakened. Two potential causes would be that someone accidentally introduced some AC onto the track. The other is that if the plastic worm shaft housing was misaligned long enough it may have overheated the motor. Have you tried testing it with an ammeter? If you do not have one perhaps a friend or a hobby shop does. It may be that the motor needs replacing (and given how plentiful Athearn of that era is at swap meets, perhaps that is not an expensive fix and may give you a nice dummy engine into the bargain!).
Dave Nelson
Mine is in parts right now. It was a slower engine, even after I added a new motor. More than likely it is the gears in the trucks. I did add weight to mine and it pulled around 20 cars or so, but I have not ran it in years. I went DCC, it was missing its hand rails so I never installed a decoder.
Add some wights to the inside of the shell and have fun.
Cuda Ken
I hate Rust
I'm mostly a O guage guy, but have been playing with HO as of late. I picked up one of these and it runs pretty good, nice and smooth running loco. Both of the trucks are powered by driveshafts. It doesn't pull as hard as my other loco's and if my consist is to big it really labors and spills the wheels, I figure that's due to the lack of traction tires. My question is are these older units just not as quick powered as other loco's or what? Every one but this one if I run it them by itself they'll fly off on the corners, this just goes at a moderate pace. I'm still debating on weather on not I want to keep it. Who else has one of these and how's yours run? Thanks