jumpy 736

[martinden]

FWIW, my 736 has sparked at the right brush from the day we got it new in 1953. Some years ago, I made a determined effort to cure it -- new brushes, extensive cleaning of the commutator, etc. It still sparks. So does a 681 I bought (used) a few years ago. I think it's just "in the nature of the beast."

[lionelsoni]

It is also possible to shim an axle without pulling a wheel, by cutting a slot in the shim washer. If you make the slot just a little narrower than the axle diameter, you can force it onto the axle, but it won't fall off.

[andregg1]

HI
How work in reverse?
Because, in my 736 I found that one midle wheel is little bit bend and touch the traction wheel in some points.
When go in reverse the motor move the traccion shaft into and the wheels touch one each other more, the result is terrible.
solution: take out the wheel and add shims between the wheel and body..
Andre.

[Anonymous]

thanks jim. I will try to get some new brushes. the old ones are about 1/4" long and seem to be full length. when installed the back end is almost flush with the brush holder where the spring contacts them.
john

[Anonymous]

John,

I think that the problem could be the brushes or the springs. I know from experience that when the brushes in a 736 Berk or a 681 Turbine become too short, the locomotive will jerk at low speeds. The brush springs may also be weak, but I would try replacing the brushes first to see if that solves the problem. Never adjust brush springs, replace them. I would not be concerned about the brushes sparking. You will notice that the right brush sparks when the loco is running forward, and the left brush sparks when running in reverse. My 681 and my 736 both do this sparking. You may also want to clean the reversing unit, and test the armature for open or grounded coils while you have the locomotive apart. Let us know what happens.


Jim

[Anonymous]

I recently acquired 1951 736 Berkshire. I disassembled it and did a complete service. the brushes and commutator looked fine and only got a cleaning. my problem is when running at low speeds it is jumpy, it lurches. at higher speeds it runs smooth but I see sparks from the right brush. It seems to need more throttle to pull the same load as my 2035. has anyone had a similar problem? any input is appreciated as I enjoy running at a slow speed. Thanks, John