Mobile 1 red grease is best, does not hurt plastic, has no effect with temp. Mobile 1 10W50 oil same I use in my truck. sticks to bearings does not run off. Every lionel, MTH and williams purchased on e bay first thing is pull the motor off and check the brass gear void area dig the old grease out esp the yellow Lionel grease. fill the cavity with grease rotate both brass gear and the motor shaft gear filling all spaces with grease. most likely will never have to do it again.
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