Marklin 88092 with two wheel leading truck.

With the invention of the steam locomotive in the 19th century came un-powered pilot wheels as part of its invention, they were meant to support the front end of the boiler and assist the locomotive negotiating curves. John Jervis is credited with the first locomotive design incorporating leading wheels or pilot wheels for his 1832 4-2-0 locomotive. It would be another 33 years until the design of leading wheels would be improved by William Adams, his 1865 design allowed the front bogie to slide slightly to negotiate curves and a spring mechanism to thus allow the bogie to reorient to center. A two wheel leading truck is referred to as a ‘pony’ truck, four and six wheel leading trucks are considered more stable than pony trucks for high speed service. As a point of clarification the pilot of a locomotive is located on the front of a locomotive to deflect any type obstruction which would otherwise derail the train, various designs were built into 19th and 20th century steam locomotives of a mostly filigree framework, later solid sheathing was incorporated in the streamlining of many diesel designs in the United States.

Marklin Z steam locomotives incorporate sliding lead wheel sets with a spring mechanism made of tension brass. Even in Z the leading wheels are important to running long steam locomotives successfully. It is another example of Marklin being true to the prototype even in the smallest scale.

I recently bought 88272 as ‘new dealer old stock’, it was released in the mid 2000’s as a One Time Series, it sat on a shelf for over 10 years with plenty of time for the oil to harden. I tested it at low voltage and it worked flawlessly without any hesitancy so I tried it on a large oval, the pilot wheels derailed on the first curve: hardened oil syndrome on the pilot truck pivot point as well as the trailing truck’s pivot point with no sign of hardened oil in the gearing of the driving wheels. Cleaning the loco of all the old oil and re-oiling solved the problem! Advantages with Marklin Z are the easy to diagnose and repair problems: always look for the easy answers.

After making the repair I compared the 88272 BR 42 with the 88273 BR 41 both are closely related with the same chassis and shell , leading wheels and trailing wheels on the 88273 do not include the tension brass mechanism supporting the axle on both trucks. If the slight tension created by the brass spring is too much the wheel set will deform below the surface of the driving wheels. Removing the brass tension mechanism if it is deformed or damaged is recommended, if it is left in this case derailments will ensue.

Since entering the community of Z I have been told by many that the two wheel leading truck on some Marklin Z steam locos cause derailments due to not enough weight on the front end of the locomotive, it has been advised that placing lead weights to the front end by soldering bb’s is the answer to fixing the apparent Marklin design flaw. We might all like to tinker, but as a long time collector of Marklin z gauge I found no evidence of design flaws in z by Marklin quite the opposite, I continue to marvel at locomotives and rolling stock designed for long term running characteristics which are easy to maintain and repair.

I collect Marklin mini-club as my primary railroading enterprise, but I also collect prewar Marklin 1 gauge and prewar Lionel Standard gauge. As a point of comparison I pulled out the motor and pilot wheels of my Lionel 384 from 1930. In the photos the itty bitty Marklin Z 88273 incorporates leading wheels that slide on their axle whereas the big Lionel loco restricts the leading wheels to pivot only on a vertical axis.

Photo: Lionel 384 pilot wheel and Marklin 88273: behemoth and the “Little Giant!”

Photo: Lionel 384 2-4-0 locomotive motor with driving wheels and leading wheels juxtaposed next to Marklin 88273 which incorporates a sliding axle not present in the 1930 Lionel.

I would say in closing that Marklin has already considered the leading trucks as important elements and not decoration in their design which accounts for historical accuracy and perfect operating characteristics, modification to the leading truck maybe overlooking the real problems which could be dirt or hardened oil around the pivot point or too much downward pressure from the brass tension spring. The same applies to the trailing truck. Always look for the easy answers instead of reinventing the wheel.

Good luck and have fun!

Siding: Gearing on Marklin Z gauge steam locomotives usually comprise driving wheels with connecting gears. Connecting gears are installed first followed by the driving wheels and side rods. It is a little tricky working with small parts, but the objective is to line up all of the wheel weights in correct orientation otherwise the loco will not run smoothly instead the gears will bind up. Tell those around you that you may need a 1/2 hour on your hobby or 6 hours when you make your first steam locomotive repair.

Siding: if that set of pilot wheels keeps derailing it will more than likely be dirt or hardened oil around the pivot point, pilot wheels should move freely around pivot point.