MTH Premier N&W J curve issues

Remove the trailing truck and see if problem goes away.  Check gauge of drivers, maybe too wide?  G

I tried to take off the rear truck while I was home this past weekend. However, there are electrical pickups that rub against the rear truck axels. Look like a ground of some sort. To separate the truck would have required opening the shell and with such a short visit home, I was reluctant to do that. As to the gauge of the wheels, I have calipers, but am uncertain of the specifications. Perhaps when I go home again, I can measure the spread and compare to the engines that work.

I still wonder about the rollers. If they are oversize, it might lift the body just enough so that adhesion is poor.

Make sure I am reading this correct. Runs fine everywhere else but your track?  Few questions, is our track level or has a steady grade, no bumps or dips that something can get hung up?  Forward and backwards? turn the engine around and does it do the same thing forward and backwards?  Build a test track on the floor and see if you get the same results.

Level track, well screwed down and ballasted. Platform has been up for nearly 20 years. All other engines work fine. Reverse is the same as forward. I will not be home for another month or so, but when I do go home I will set up a track on the floor using different track. There is plenty of torque, it is just not reaching the rail head.

Thanks for the suggestion.

Regards,

Bill

I would occasionally have a similar issue with my Railking Hudson.

The trailing truck, like the prototype, has an axle with a smaller pair of wheels and another with a larger pair of wheels. The larger wheels were lifting the driving wheels slightly off the track at times. I had to make a few other adjustments with the other, smaller wheels and axle and reseat everything and it runs fine. Might be a similar issue with your engine. I'd definitely try to run it without the trailing truck.

Real steam locomotives used leading and trailing trucks for 2 reasons: "steering"/guidance in one or both directions (some of those big articulateds with little trailing truck wheels had them for steering while backing up), and, pertinent here, to share in what is called "axle loading". They are supposed to carry some of the weight, ergo, some of the weight is off the drivers. This was adjustable.

If your trailing truck is "pushing down" on the track too hard, the drivers will have less adhesion. Is something bent in the suspension/drawbar parts on your tailing truck? Is something jammed? Is the spring too stiff (can't imagine this, but...) Is the truck swing constricted? (I have had to wrestle with this on a few brass locos - sometimes a low-hanging piping detail can get in the way). If it (the truck) wants to lift off the track it definitely can cause an adhesion problem. 

My 3/2 rail MTH J has been a poor performer (see the posts under the MTH steam thread on the two rail forum).  The biggest problem was electrical pickup issues associated with the wireless drawbar.  A secondary issue is that for a heavy model it's pulling power was disappointing - is significantly less than a lighter  brass  locomotives with the same number of drivers.    One factor is that the leading and  trailing truck springs were pretty stiff, serving to partially unweight the drivers.  Once I get it back in service ( I'm waiting on a replacement drawbar) and ipast the one year warrantee  I may play around with the pilot and trailing truck spring tension.  One test you can make is to put the locomotive on the track (Power off) and with a flat blade screw driver see how much vertical travel the leading and trailing trucks have.  With not too much force the truck wheels should be able to lift off the rails without the drivers losing contact.