Lionel 2026 (later version) - question about pilot/trailing trucks

[Benjamin Maggi]

I have a later version (2-6-4) Lionel 2026 engine that runs nice but sometimes the pilot truck derails on sharp curves. When I pick up the engine the pilot truck just flops around like crazy. I see there is a spring in the assembly and it "sort of works" if the pilot truck is lifted above the rails but the spring doesn't start to compress until the wheel is nearly hitting the underside of the engine. Can someone post a picture of how the engine should look underneath when it is properly set up?

Also, I really don't like the trailing truck at all. I think the two wheels of different diameters looks unattractive. Would the single-axle pilot truck of an original 2026 drop in if I wanted to replace it?

Thanks.

[lionelsoni]

Those locomotives suffer from an incorrect steering geometry, which causes the pilot truck to oversteer and often derail on curves--the sharper the curve, the greater the effect..  If you put the locomotive on an O27 curve, you may be able to see that the pilot wheels are not parallel to the rails, but angled toward the inside of the curve.

The pilot truck should have a longer tongue and should pivot around a point midway between the pilot-truck axle and the middle-driver axle, which is about where the motor's front crossmember is located.  You may get along with a stronger spring or more weight on the truck or both; but, if you're willing, the real cure is to splice on a longer truck tongue and to create a new pivot at the correct location, as by drilling and tapping the crossmember.

[cwburfle]

Locomotives like the 2026 described above work fine on 027 track. There is no need to modify the engine. If the front truck is derailing, then something is probably bent.

Spin the wheels and look for a wobble (unlikely, but sometimes the axles get bent)
The little hook on which the pilot truck mount does get bent sometimes.

Read the following for Lionel's tips on how to fix your front truck. It isn't your exact engine, but the information applies: http://pictures.olsenstoy.com/cd/locos/loc2026a.pdf

[LL675]

yes you can swap the four wheel rear truck for the earlier two wheel truck.

[Benjamin Maggi]

Thank you to everyone for your help!

[BigAl 956]

Replace the spring.