mth hudson drive wheels binding at the same point

Be sure that the wheels are properly quartered, and all 3 wheels on each side are identically mounted--side rod screws pointing precisely in the same direction.

thank you for the info. I will double check ,but I did check that once. 

Check to see if one of the wheels is loose on the axle. It can go in and out of quarter if a wheel is loose.

Any other part of the linkage that gets bent, may also cause a binding issue. As posted above, you have to check precisely. Close enough won't help here. Maybe you could narrow it down to a specific axle?

 Did you remove the eccentric cranks on either side for maintenance or some other issue? Have they slipped?

Try taking those off one at a time and each drive connecting rod, one at a time until you find the culprit.

When you replace the rods, only replace the siderods leaving the eccentric and main rods off and see how it rolls. If it rolls free then check that the crosshead can move freely in its guides. If those slide freely then maybe the eccentric is not in its correct location slightly off axle center.

Pete

When I start turning the flywheel, all the wheels, both sides, are where they are supposed to be but as the y get to an extended position the front wheels do not keep up with the others. Is it possible that the side rod holes are so worn that there is too much play for the front to follow the back wheels properly.( The gear driven wheels.)

Also, thanks for all the possible causes.   I will be trying those as well.

On this engine, The front and center wheels are free wheeling and it is up to the side rods to synchronize them.

I neglected to identify the Hudson engine as a MTH rail King  Cab#5412 product# 30-1146-1

One trick I use for identifying the suspect wheels is when you get to the bind, just wiggle all the siderods.  The ones that are tight are the ones to look at.

Did the rods bind before you removed them?

If not, I'm with Pete. You may have reinstalled the eccentric crank in the wrong position. They are usually notched for position but can be installed 180 degrees off if your  not careful/sure.

They only way to be sure is to use a photo of a similar Loco for reference and install the rods the same way provided the wheels are in the exact same position as in the photo.

Ideally photos of both sides of the drivers.

If you are unable to "google"  a photo, maybe a fellow forum member could post some on this thread.

I thought from the first post that he already had the binding before removing the rods.  Obviously, if that happened after removing the rods, the eccentric crank is high on the list of suspects, been there, done that.

The engine stopped while running it. I took it apart and insured the front two set of wheels had no binding, relubricated them. Removed the motor cleaned all the grease out relubricated that .. also,insured that there was no binding in that set of wheels. I removed all the linkages except the side rods and the binding is still there when I manually turn the motors flywheel. The wheels always bind in the same position. Again, it seems as though the holes in the side rod may have become too large and there is too much playin them for the front free wheeling wheels to not bind. They just don't maintain the same position as the back to set of wheels. Thank you for trying to help with this problem.

Allan

There is normally some slop in the rods, there has to be a bit of leeway to allow for minute misalignment issues.  Unless it's been run A LOT or totally without lubrication, it's actually pretty difficult to wear the holes to a degree where this would be an issue.  It's far more likely that it's something else.

Another possibility, though it's also not common unless the locomotive has been abused, is the wheelset is out of quarter.

Checking the wheel "quarter" visually, they all look correct  90 degree difference. Thanks