Coupler difficulties

[Steamjohn]

  I've a Lionel B&O Mikado w/ standard railsounds, looks good runs good, whistles chugs and smokes.  All is right w/ that end.

  The problem I have is every so often the tender coupler opens up.  My trains is 6 or 7 cars long, and I've tried shortening the train and I've still got the same issue.  It seems to happen right after I blow the whistle for a crossing, but not always.

  Any ideas??

Thanks

John

[sir james I]

If it has a coil coupler you would have to remove the knuckle and replace the spring. If your running TMCC or Legacy it could be a signal issue. Those out of the way leaves the pull down type of coupler the fix depends on which type of knuckle armature is being used on your tender.

[gunrunnerjohn]

A common issue with coil couplers is noise introduced into the electronics.

Before you rip the coupler apart, unplug it from the TMCC control board.  Run the train long enough to see if you still have the coupler opening issue.  If it goes away, then it's electronic, if it still opens, then it's mechanical.

For electronic issues, one common fix is to put a 1uf 50V non-polarized capacitor across the coupler.  You can do that on the board, or splice it into the coupler leads somewhere along the line.

For mechanical issues, the previous advice of replacing the spring is probably correct.  You can also get a new coupler for $10 and replace the entire coupler.