2-6-6-2 engine locks up

[krs2530]

I've had the HO USRA 2-6-6-2 with Tsunami for a couple of years used maybe ten times, pulling 20 cars on level Club display oval layout for an hour or so at a time. After the first few sessions the rear engine began to lock up, and continues to do so, sometimes a couple of minutes after starting, sometimes 30 min. Lockup may occur in either direction, and I don't really know if its always on a curve or not. Sometimes, but not always, it will unlock by reversing direction. Mechanism seems perfectly free-running right up to lockup, and front engine continues to operate normally while rear is locked. I have lubricated the external stuff, rods, valve gear etc. Has anyone experienced similar lockups with this engine or with the H-4, which I assume has a similar mechanism?  If so, was the problem in the external stuff, or in the internal gear train?

Bob

[ebtbob]

Bob,

      I had a similar problem with a Blackstone K27.   I found that due to the lateral play in the front driver,  the large screw holding the drive rod to the driver was fouling another part of the linkage,  thus causing it to jam.

[bobwrgt]

Run it slow until it locks up. Don't move it. Then get down close with a tooth pick or small screw driver and see if any of the linkage is binding, hitting, or locked up against another.
If it is, you may have to tighten a screw or adjust the linkage so it does not hit.
Also turn the engine over and look close at the copper/brass contact strips on each wheel for electrical pick-up. See if one is bent and getting caught on the wheel spokes.

Bob