dheaton,

        One of the best things about this hobby is that it can and should be enjoyed in a multitude of ways!  That being said, I personally like rebuilding and building locomotives, especially older ones.  However, is your GS4 a pancake motor version?  If it is then good parts are very difficult to come by.  Most likely Bachmann will not have them in stock or even able to get them.  If it is a newer type with a can motor, then I would try and order the drive wheel assembly.  I checked with Bachmann website and they are currently sold out.  From experience gluing the axle back into the plastic sleeve on the axle is difficult.  If you try that make sure your timing is correct before the glue is applied for your drive wheels!  Once you find a glue that will adhere, you will not be able to adjust the timing like you can with a good axle sleeve.  Other things may be able to correct this problem as well though.  If you have access to a small mill/lathe, you can make the sleeve and use it as intended, a friction fit.  If it was me, I would send the locomotive and basic cost to Bachmann.  Hope this helps,  Stephen

In my mind you have a short!  Since the rods were heating up, logic would dictate that be the area of the short.  Without looking at the loco itself it would be hard to judge any corrective action.  Maybe check the wipers/pickups and see if they have bypassed an insulator somewhere.  Hope that helps,  Stephen

Shouldn't be a problem with the three truck version.  I just obtained one myself and it runs fine.  Stephen

Due to the gearing in the trucks, you won't be able to turn them that way.  Try taking the shell off again and turn the flywheels or drive shaft.  If they won't turn easily then your trucks are binding for some reason.  Hope that helps,  Stephen

It burns them out after a short while.  The blinking light is designed for 12v DC current and the AC type from DCC makes it burn really bright for a short time and it won't blink.  What I did was cut the leads on one of the bridges and the other I put in a LED light with a resister in line.  Didn't blink rigged that way but was what I had on hand.  Hope that helps.  Stephen

From past experience....blinky light bridge bad on DCC!     

Mark,  I echo the above wholeheartedly!  Jeff is also correct, Bachmann DCC GP4's don't come with flywheels.  However, I like to build and rebuild locomotives, rolling stock etc.  I have a small parts machine shop so I have an advantage there.  I mill out an area in the frame and then turn smaller than usual flywheels.  The only thing I have noticed is a bit smoother performance than without.  But bear in mind it is a lot of extra work for a barely noticeable improvement.  I do it just because I want to get the best out of the locomotives and I really enjoy the challenge.  Remember it's your railroad and always have fun!

Me too!  Got a good bit of small parts and the discount helped considerably. 

Don, I obtained the maintenance ideas and procedures from a very informed individual from this site.  His first name was Sheldon, I don't remember his last, but I tried his methods and they have worked wonders for me.  He sent me specs and charts that he worked up!  It has been great infomation.  Because of his work, I set my standard for rolling stock and locmotives pretty high for model work.  For loco standards, a locmotive has to pull twenty five rolling stock up a one percent grade by itself.  I can do that without overloading the motors but that requires that my rolling stock be equally re-done to match.  Sheldon showed me how to rework the trucks and I now do that with every truck no matter the manufacture.  I properly weight them and they run so easily and smooth they almost run themselves!  lol   Of course the little locos don't have the tractive effort for that to apply, but Sheldon's info really has helped me work my little railroad as close as I can get to the real thing.  have fun,  Stephen

Dear Sid,  I guess I'm the crackpot!  I use initially, a very small amount of lube on the axle points when I rebuild the trucks!  I don't even work for Kalmbach!!  What can I say!        Stephen

ali.
   Don's math is spot on and I agree with Jeff.  However, my Helix is at approx. 30 inch curves and I rise approx. 16 inches with three and a half turns.  From my experience dealing with this thing, I would suggest you stay away from 18 or even 22 inch curves.  The locos may make it a few times but even with really good track work they will derail in the helix!  Mine is just under 3% grade and I used the princple Jeff is describing.  They can be a lot of fun once they are set up correctly.  My next one will be under 2% grade.  Better to have many curves over a wider plane than short tight ones.  Hope that helps some,  Stephen

WOW!  I'm not quite that old but Moses was my first reporting official!   

Take the shell off and run the powered chassis on the layout.  Watch what happens to the front and rear truck!  That should gives us a good bit more info.  Stephen

All, just a little FYI.  You can put flywheels in teh GP40/50/38/etc.  I do it on a regular vasis.  I used to buy the flywheels but now I turn my own "custom" flywheels.  Usually you hace to "remove" material from the frames and a little patience making the drive shafts.  If you have the money and don't have the time, it is easier to put in and hardwire a decoder.  This Winter has been rather light on the railroad but last Winter I assembled/built over 15 DCC locomotives with the custom flywheels, custom motors and drive lines.  If anyone is interested I would be glad to share what I have learned in this process.  Hope that helps!  Stephen

Check the Bachmann site on the parts page.  I don't know if the current drive shaft will interchange but you could call and ask them!  Stephen