Greetings All - I have recently purchased a Bachmann Spectrum GP-30. I believe that it’s about 10(?) years old (+ or - ). It is making a “grinding” noise when I run it in reverse ( long hood backwards ). I have dis-assembled it as far as checking the trucks/gears as well as checking the screws that hold the two insulated sides of the weight unit together on this model. Everything there seems OK. My question; should I be checking for cracked gears/mis-alignment of flywheels or something else? I’m not afraid to completely dis-assemble it, however would prefer not to.
It’s a beautiful model, decorated for UP, #731. I’d hate to have to sell it at a loss, but…
It may be vibration but I’d think you’d get the sound forward or backward if that were the case. It could be a loose or worn gear someplace. In nearly all cases with a cracked gear you’d hear a thumping sound when the loco is running. As for the noise though, I have two NEW Bachmann GP30’s and they both growl along like Athearn blue boxes.
I have several Bachmann DC OnBoard loco, boht standard and SPectrums. I have been happy with them all.
Only one makes a low growling move on start up and at slower speeds.
If it bohters you and you are nto afraid to take it apart, then go ahead and do so.
If you don’t want to send it o to Bachman’s repair center in Philiadelpia, PA and let THEM do the work and replace any “needs replacing” parts. As I understand it they have a GREAT service departement, even if it is out of warantee, you broke it, or you tried to fix it first. If you have to pay any fee whatsoever, it is usually small. If they can’t fix ti, they will send you a new one of same if they can, Or one that is acceptable to you as a replacement. Worth looking into, I’d say.
I had bought 2 of these about 12-14 years ago. Was never thrilled w/ Bachman diesels to begin with. Only bought them due to the offering of the B&O blue Capital dome and the Sunburst paint. Was a big mistake, should have gone with my initial feelings about these things. Both were poorly painted, details were crudly installed and they both ran like crap. Even the average Athearn BB right out of the box w/o any tweaking ran better. All the usually fixes and lubing didn’t really help. I never did find the reason/s whether it was motor, drive shaft or something in those “horrible” truck truck design. Offed them as soon as I could and returned to buying only Atlas, P2K and Stewart’s (12 years ago) Don’t know what to tell you, even quite a few club members have had same issues w/ their GP30’s. Can’t figure how a manufacturer can make such a piece in diesel w/ such poor all over the place quality, yet the Spectrum steamers are quite nice overall. Go figure…
I have never managed to figure out why some of the Bachmann engines do this but i have some that did quiet down. You can try seeing if one of the drive shafts are bent causing vibration, Bend it streight if you can. If there is excesive play in the drive shaft betwen motor and worn gear you can slide the coupler on the worm gear shaft toward the motor to remove the play. Sometimes if you remove the wheel sets from the trucks and swap them around it will also quiet them down. Just the way some gears mesh. The screw that holds the truck on top can be to tight and the tip of the screw can hit the worn gear. Back it off and see if it helps. You can also try swapping the trucks around from front to back. After trying all of the above i have engines that turned out to be good quiet runners and on a few i got replacement trucks from Bachmann under warranty at no charge that solved the noise.
If worse comes to worse, a Blue Box Athearn GP35 drive should fit under it. Just a little grinding on the frame to make it fit.
I did my pair 17-some years ago.
The original drives had a bit of slop in them, lot of surging coming down a 4% hill with a decent train behind. Athearn drive works much better. I also added weight, 6-7 ounces or so.
After that, I decided not to buy any more. Luckily P2K came out with their GP30, which has a much better body and drive.
