Linkage binding up

Normally this type of linkage is trouble free as there is a lot of free play in it.  I have encounter problems  when the linkage is bent. Sometime even when the piston rod is too straight it will bind. The only way it solve this issue is to remove the rod from the wheel and manually push it in and out to see where the problem lies.  Most times the binding occurs at the slot that the piston rod moves in and out of.  If the piston rod does not offset enough (ie: is too straight) it will rub and bind as the rod is pushed into the slot. Bent rods will also bind but your piston rod is straight.

The joint you pointed to with the pencil is not likely to be the location of the binding.  I would examine the piston rod and gently bend it away where it is rubbing at the slot in the steam pistons.

Your problem has become apparent when? When you first tried to run the engine or after you ran the engine? First I would try to decide which side rod linkage was binding. Which side becomes tight when rotating by hand the armature. The side rod linkage should be approximately 45 degrees offset from side to side. Otherwise there will be a binding. This is caused when someone replaced a gear driver and placed it in the same position as the other side. also check for blockage in the steam chest. Try moving it in and out by hand and see if there is tightness at any point along the way. See if that will help. then lubricate the whole engine.

Donald Payer

It looks to me like you don't have the cross head aligned correctly in your picture.  Could it be that you don't have the rod (left side in your pictures) lined up with the correct slot in the cylinder?

These two photo's are from a 290 Steamer,  make sure yours are oriented like these are.  Hope this helps!

In your pictures it looks like the tab on the end of the drive rod is bent too far inwards. It should be parallel to the main rod, or even less than a 90 degree bend, if that makes sense. It should stick out just slightly, so that it does not force the piston assembly to slant inwards.

Hi Roy,

I am not the the originator of the question, binding linkage but I do see your point and he should also try your suggestion as well as the suggestions that I suggested. From those pictures it is hard to determine the actual problem. SHOOter is the one that should be asking more questions if what we have suggested has been tried and still has not resolved the problem. Thank You for your input.

Don

Don....and others....was unable to check the forum until today and found the linkage did in fact need some "tweaking".  A small adjustment at both the main rod and cross head did the trick.  Checked my other "problem child" and it now works fine.  Thanks to all for the help...and apologize for not getting back to everyone sooner...