New to DCS and Forum with huge problem

Well, I would guess the front truck tension spring was off a bit, but hard to tell at this point.  Be happy you fixed it and enjoy yourself.    Here's a pat on the back for you

.....

Dennis

My experience is that for some engines and cars it does not take much for the offending truck wheel to start "climbing" the rail at a switch or turn. And in some cases that just may be the particular engine and track combination rather than a defect.

What is the engine length, track radius and track (Atlas, Fastrack, etc.) you are using?

Can you turn the offending truck by hand by holding the engine in the air   with one hand? I'm  thinking of short motor leads or other wires  preventing the truck from turning.

Lionel o gauge 031 track. That's what I was thinking also that's why I redid wiring and took front coupler off because that wire seemed like it may be binding. Just  thought very weird that it had run couple hundred miles fine.

I guess what made the least sense was that it ran fine without the shell on. 

I am having a blast but dogs are getting worn out because I am running till 3 or 4 Am.

Big E, that's a 17 1/2 inch long engine. Even though MTH Railking is 031 by default you are at the very limits of truck rotation -- I would think -- on an 031 curve. I have a couple 17 inch Williams engines that simply won't work on my Atlas 036 curves due to overhang. IMO consider yourself lucky that you were able to fix the problem.

Scott its a premier not railking does that make a difference? 

Oops my bad, it is a Premier but the catalog does say 031. That's surprising for a larger Premier diesel. I have seen some that I really wanted to buy but the catalog said 042 curves. Still, the derail is not surprising for a long engine on tight curves. Makes it that much better that you were able to get it to work.

I had a an engine I wanted on eBay that said 031 in the catalog but the Seller listed as 042. I asked why the difference and he said he had some returns in the past for the same problem you're having. For my 036 layout I always check the engine length. If its greater than 15 inches or so I pass. Which is a bummer because there are some great engines -- like yours -- that I would like to run.

BigE,

    I think if you check your engine is rated for 036 not 031 and you were just lucky for a while, what ever alteration you made now lets the engine run thru the 031 curves again.  Consider yourself luck she runs thru the 031 now.

PCRR/Dave

Hi Dave, this one is rated for 031 the new ones are not. It is built with the inside wheels having no flanges. 

Also forgot to mention that it had clocked hundreds of miles on 027 curves until I redid track to 031. Just wish I knew because would like to put coupler back on but fuse budget is low right now...lol 

I bought this from hobby shop  that has consignment pcs for 200 so I guess I should be thankful . being un run  

I have 2 of those engines! the minimum curve for those engines (SD40-2) is 0-42:

http://mthtrains.com/content/20-2862-3

There have been some older MTH-Premier SD40-2 that were rated to run on 0-31 curves:

http://mthtrains.com/content/20-2363-1

........rogerw.

If you are blowing the TIU fuses, it won't be long before you do major damage.  You need a proper 10A or smaller circuit breaker between the old PW-ZW and the TIU power input.

No John, thanks to you already had tvs and 7 amp quick blow fuses in place before I even went to DCS.

Thanks to everyone guess for now live without front coupler on her.