GP 40 diesel stops running at crossings

[Fish]

I have a 2 Bachmann diesels.  The older of the 2 (1+yrs) stops running when it hits a switch or crossing track. The newer of the two has no issues whatever.  It runs smoothly around the entire layout, crossings and all.  I am using code 80 track and crossings.  Tracks and wheels have been cleaned, but for some reason I feel I am losing electrical contact at the switches with this one diesel.  Any thoughts?

[spookshow]

Check that the wheel gauging is correct. If slightly off, the wheels could be losing contact with the rails when trying to squeeze through a frog.

-Mark

[spookshow]

NMRA sells a metal gauge tool that allows you to test various spacing (wheels, flangeways, points, rails, etc). Pretty much any hobbyshop that sells model train stuff should carry them (otherwise, they are available from numerous online dealers).

Put each wheelset into the notches labeled "wheels". If both wheels fit in comfortably, they are in gauge. If they don't, either slide the wheels further out on the axle or press them in tighter (depending on which way the gauging is off). I generally use a small jeweler's screwdriver (prying gently) to widen the gauging. Squeezing with one's fingers is usually enough to tighten the gauging.

-Mark

[plas man]

could the fault be large flange wheel's (pizza cutter) , the good running loco may have finer scale wheel's ?
the larger flange causing the loco to lift ?

[spookshow]

could the fault be large flange wheel's (pizza cutter) , the good running loco may have finer scale wheel's ?
the larger flange causing the loco to lift ?

Given that the OP stated that he has Code 80 rails, that shouldn't be a problem with a Bachmann GP40. There isn't an N scale Bachmann loco on this planet that can't handle Code 80 rails.

-Mark

[James in FL]

After you check the wheel set gauge, check that both trucks are picking up power.

[gatrhumpy]

Don't solder that because it's plastic. Get a cheap GP40 on ebay if you want to replace the engine.

[Rich_S]

To add to my problem I just discovered that one of the motor shaft couplers has come off.  I believe I now need to replace the motor.  However the parts store says the GP 40 motors are out of stock and / or discontinued.  I wonder if it possible to solder the coupler back on to the motor shaft?  Otherwise I am open to suggestions.  Hate to lose the engine.  it cost $35 to purchase a new under chassis.  Almost the cost of a new GP 40 diesel. I hope I am making myself clear as to which part is broken. It holds the plastic propeller shaft that connects to the trucks.

You cannot solder plastic, I'd try a small drop of CA (Super Glue) to attach the coupling on the motor shaft. Be careful not to get any glue in the motor or you'll be done. Also as another poster mentioned. make sure the bronze wipers in the truck side frames are properly contacting the frame halves and are not dirty. If one of the bronze wipers (labelled on the drawing as truck pickup shoe) is dirty or not contacting the frame, it will cause your locomotive to stop running at a turnout or crossing.  One more suggestion, do not over tighten the frame screws when putting your locomotive back together, a very light pressure snug is good enough, to much and you'll strip out the plastic screw holder. Hope this helps?