Question about fixing Southern Pacific GS-4 / 4-8-4 Locomotive

[M1FredQ]

Dear Folks:

Bachmann finally returned the loco's I returned for repair.

They did a great job and sent them back in nice safe packaging.

Everything runs and operates great. The smoke from the GS-4 "puffs" up

in intervals and it wows everyone that sees it.

PROBLEM:

My son noticed that the hexigonal nut that holds the rod to the REAR FLANGED WHEEL on the port side(Left) side comes loose.  I tightened it and after a few laps

around the layout starts to come loose again. Any suggestions on what to do and

why is it unscrewing.  It's the hexigonal nut for the axle of the rear Helical Gear.

This is a great engine!! and really impressive looking on the layout with its red

and orange colors.

Thank you in advance.

Thanks everyone

[Bucksco]

Your local hardware store should be able to supply you with a tube of "loctite". It is a liquid used to secure screws in place. All you need is a drop on the threads of the screw in question.

[M1FredQ]

Thanks will do and will report back

[M1FredQ]

Until I can get to the Hardware store I used some melted wax on the screw

then screwed it back in. Last night my son ran the loco for about a half hour and

it was still holding!!!!!