726 Berkshire difficulties

[Steamjohn]

  I've got a Lionel Berkshire w/ some issues.  Well 1 major one, the screw holding the main driving rod, and bellcrank to the centerdrivers keeps backing out, no matter how much i tighten it.   Can I put a drop (just a drop) of blue loctite on it?  I was thinking og applying the loctite, and letting it dry..then re-installing the screw. 

  Thoughts...advice, anyone?

   Thanks

   John

[Stourbridge Lion]

Steamjohn - Welcome to trains.com!

[gunrunnerjohn]

Clean the screw and hole with some alcohol, let it dry, and use the Blue LockTite.  Don't let it dry, put it together and then leave it for 24 hours.  That should do the trick.

[TrainLarry]

John,

Welcome to the forum!

The screw should not normally come loose unless the threads in the wheel are worn, or the screw is worn and not engaging tightly. Another possible reason is if the studs on the end of the eccentric crank are worn where they fit in the wheel, or the wheel is worn where the eccentric crank fits in. This will cause the eccentric crank to move in the wheel, loosening up the screw. Check the screw, eccentric crank, and wheel for wear, and replace any parts needed.

  If you need to use Loctite, use the blue threadlocker #242. You must apply it to the threads and assemble the screw, and let it cure assembled. The product cures in the absence of air, so it will not cure just by coating the threads and leaving it stand out in the open.

Larry

[John MS]

I would go with the bad locating nibs on the eccentric crank. this is a common problem. if you tightened the eccentric crank when it was not properly quartered these nibs will shear off.. look closely at the eccentric crank and see if the nibs are still there. when reinstalling the crank has to be in the correct position or damage to the crank or side rods will occur. I stay away from loctite on small screws like these, could cause more problems down the line when trying to remove them.

[lionelsoni]

A bellcrank is something else entirely.  The right term is "return crank" or, not quite right, "eccentric crank".

[John MS]

thanks bob, my thoughts were split at the moment.

[Steamjohn]

 Thanks for the welcome!!!

 

[Steamjohn]

  Thanks for the welcome...glad to be here.  I'm thinking the wheel itself may be stripped out.. I hope not!