I recently bought a first generation Athearn Genesis SD70 from ebay and I pulled it out with the intention of installing a decoder that's not the issue the diesel keeps running off the track and sending my DCC into fault mode it feels like the trucks are loose it can't make it around the layout without tripping the breaker anyone got a any ideas?
I have 3 early release SD75s and SD70 that are 1 step away from becoming yard decor. The wheel sets are in gauge but they do not like curves and Shinohara turnouts (#10s). I have filed rails, joiners, leveled joints till I am tired of dealing with these units. In the early stages, it was trackwork, typically even minute variances in the curve of a radius. So those were valid.
Now I have no idea. The SD 75/70 truck appears to be very sensitive to any fluctuation in rail joints in curves and the leading wheel climbs the outside rail and the truck teeters on the center axle. Maybe I should just loose the center wheel set?
Long wheel base P2K PAs and Es go through the same curves perfectly. Atlas 6-wheel GE likewise no issues. Athearn dash 2s are okay.
Warped trucks ! I had six of them with warped trucks. These were produced shortly after Athearn changed ownership and they refused to acknowledge the problem and offer to replace the trucks, so I had to purchase new ones in order to get the locomotives to stay on the track.
I shunned all Genesis products for several years after that fiasco.
duckdoggerThe SD 75/70 truck appears to be very sensitive to any fluctuation in rail joints in curves and the leading wheel climbs the outside rail and the truck teeters on the center axle.
Friend at the club bought a whole box of one flavor of those SD70s. Every one had the same problem.
Put the engine on a flat surface. A piece of plate glass is ideal. See if all the wheels are touching. I think you'll find that the center axle on each truck sits lower than the other axles, causing the pivoting action you are seeing. I don't remember if he found a cure. He was talking about doing some upward bending of something on the power truck, but I don't remember if he actually did or was successful. If I see him this weekend I'll ask.
You might try contacting Athearn, explaining what you see, and asking them if they have a cure.
grandtrunk44I recently bought a first generation Athearn Genesis SD70 from ebay and I pulled it out with the intention of installing a decoder that's not the issue the diesel keeps running off the track and sending my DCC into fault mode it feels like the trucks are loose it can't make it around the layout without tripping the breaker anyone got a any ideas?
duckdogger I have 3 early release SD75s and SD70 that are 1 step away from becoming yard decor. The wheel sets are in gauge but they do not like curves and Shinohara turnouts (#10s). I have filed rails, joiners, leveled joints till I am tired of dealing with these units. In the early stages, it was trackwork, typically even minute variances in the curve of a radius. So those were valid. Now I have no idea. The SD 75/70 truck appears to be very sensitive to any fluctuation in rail joints in curves and the leading wheel climbs the outside rail and the truck teeters on the center axle. Maybe I should just loose the center wheel set? Long wheel base P2K PAs and Es go through the same curves perfectly. Atlas 6-wheel GE likewise no issues. Athearn dash 2s are okay.
I had the same problem with an Athearn Genisis SD70MAC and a BB SD40-2 the problem was the sideframes were pushed in too close to the wheels. Move them out a bit and try again. Mine were pushed in till the stops that are cast into the frames but that was too close.
I hope this helps.
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My Genesis SD75M had a couple axles that were lifted. It was caused by the metal plates in the sideframes, which are used as the bearings and electrical pickups. I was able to remove the plates and bend them just enough to make it so all the wheels had contact with the track.
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My friend has had the same problem and The sd70 just wasnt a good run by athearn. My friend kit bashed his IC SD70 with a Kato SD80Mac and used the trucks off the 80mac on the 70 and now it runs great.
I really appreciate all of the responses and suggestions. Tomorrow I will begin implementing some of your suggestions.
Today, I removed and re-installed one long section of track including the curve where the problem appears to be the most severe. I got on a small ladder so I could look down to visually confirm no kinks at joints. I only tacked the track in place but leveled any dips or slopes, and lit an incense candle to the god of HO track work. To no avail.
Maybe 2 candles?
waltersrails My friend has had the same problem and The sd70 just wasnt a good run by athearn. My friend kit bashed his IC SD70 with a Kato SD80Mac and used the trucks off the 80mac on the 70 and now it runs great.
Oh yeah, I forgot that you could do that. The Kato SD trucks fit perfectly in the Athearn frame, and the only thing that needs any modification at all is Kato's worm/truck retainer. If the bad Athearn trucks can be swapped with the Katos, you'll have the best of the best as far as plastic SD70 series diesels go! The smoothness of a Kato, and the better detail of a Genesis!
cacole Warped trucks ! I had six of them with warped trucks. These were produced shortly after Athearn changed ownership and they refused to acknowledge the problem and offer to replace the trucks, so I had to purchase new ones in order to get the locomotives to stay on the track.
Well, I can't be sure, but I believe I have one SD75 in Warbonnet livery from both runs, and neither one does very well on a few parts of my rails. All other engines of the several types that I have, steam or diesel, have no problems.
Set the 2 SDs on a glass desk and did not notice any warping and all axles touching the surface. They just seem to enjoy climbing the outer rail of 36-inch radius curves. P2K E8s, PAs, and an Atlas 30-C went around and around without incident.
How much are Kato trucks?
Even though it is probably moot since you are likely to either ditch these or replace the trucks, I found that my outer rails were a bit below the inner ones on the curves where my SD's like to derail. I had to shim them to almost superelevated status before the motors behaved. If you can find a way to look critically for such a dip, that may be your problem.
-Crandell
Great minds down the same path...
Found the same condition at one of my trouble spots yesterday afternoon and placed a brass shim under the ties at the joint and bingo, at prototype speeds through this curve, the SD did not derail. The amount of variation can be as little as 1/32 or 1/16 inch. Sometimes it can be difficult to see.
I still maintain, trucks should not be so sensitive that a 1/16-inch can be a problem. Csn it be that difficult to design in an amount of vertical movement?
I just ran across this problem with an older SD70M I have now put into service while adding a Tsunami decoder. The problem as I see it and mentioned above is the rigidity of the truck sides. Mainly how the brass electrical wheel pickup strips fit into the truck side frames. They are a tight fit. What I did was to "loosen" them up by opening up the rectangular holes and the one round hole in the center of the brass pick ups. I also filed the notch on each end for a looser fit.
I then opened up the 3 holes in the side frames where the wheel axles go with a drill. Do not drill through just open up the sides of the hole with a drill larger than the hole. This allows the axles to float along with the brass pickup strips. When I put them on something level they now fit flush. Before there were wheels off the surface.
This is my first post but I have been lurking here for close to a year now. How do you tell if one of these is a new or old model? I bought one of these SD70Ms off ebay a few months back, brand new in the box. I havent ran it yet either. I have my fingers crossed.
The earliest releases of the SD70/SD75s did not have any of the details such as awnings, grab irons, and railings factory. installed.
I used the SD 80 MAC trucks, they're available on the Kato web site. The trucks are $25.00 ea. + $2.50 for truck details. Not cheap, you'll like how they work though.
Mike
The older ones also have smaller gold colored can motors by Buehler. The newer ones have a large silver motor by Roco. The newer ones have a more refined mechanism than the older ones, so I hope yours is a newer one! My older run SD75M took some adjustment to run very smoothly, and it makes a faint grinding sound in the gears (the gears are slightly off-center, so they bind just enough to make noise, but not enough to hurt performance). I still like it, though.