Happy New Year friends,

I have a problem with one of my Marklin steam loks, a class 18.4 from the starter kit 29855. It was running very poorly - stuttering etc. At first I thought an over oiling issue, so I have disassembled and cleaned the motor thoroughly. I had also previously replaced the rubber tires, which required disassembly of a connecting rod. The lok appeared to run fine for awhile, then suddenly stopped. It now runs very poorly, stuttering and then stopping without warning. In most cases, sudden stopping is also accompanied by a bent connecting rod - which is most peculiar. I've checked the tightness of the connecting roll screws, but for the life of me I can't figure out what it going on. How a perfectly running lok can suddenly start bending connecting rods is a new experience for me. I'm hoping it's something obvious that I've done wrong - and would appreciate any advice.

Much appreciated,

Paul

Hi Paul,

The same happened once with my GT 2x4/4. A wheel was loose on the axle and would not get stuck again.
Fixed it with Loctite 638 after setting it in right phase (this process also has a name which I can't remember right now). Alternative for Loctite would be to 'knurl' the axle but that requires some machinery.

Succes! Henk

Thanks Renato, that's the right word!
Greetings, Henk

Quartering could be one cause. Another could be getting the wrong screw in the wrong location. The screws will have shoulders so it will tighten against the wheel, but allow the clearance for the rod. They will sometimes have different shoulder locations and some may even have a spacer or washer between the rod and the wheel. Did you need to remove more than one screw per side? Did you notice a very small black spacer on the work bench? I learned the hard way on my Br 45. When I replaced the tires it acted just as you are describing. It is not like the old days when all the siderod screws were the same. I now lay them out in order on the work bench and check for spacers before I remove the screws. Check M's parts diagram for the model to see if the screws are different and if there should be a spacer.