BJ8 window cranks

[woodshopdoc]

I have had great difficulty getting my BJ8 window cranks to operate smoothly and easily. The arm of one has become bent due to the force tried to raise the window. The nylon bushings have been replaced on the windows but that does not seem to help. Any thoughts? Any replacements available?

 

[AUSMHLY]

Hello woodshopdoc,

Have you tried cleaning and lubricating all the mechanisms?

Most likely the rails that the nylon guides slide in are not constant in width, or the curve of the rail is not the same as the window curve.

Another area to look into is the roller guide attached to the bottom of glass frame. Maybe that guide is bent or compressed.

Maybe the window is not set correctly in the holding frame and is binding up somewhere on it's travel up the rails.

Look into the return spring in the arm mechanism too.

Best thing to do it to remove the door panel and watch what happens. See where it becomes hard to raise and look into the friction points.

You can adjust the angle of the front rail by the two screws on the bottom and somewhat with the two screws at the top, under the vent window.

With patience and care, you can also tweak the front rail channels. I used a socket to get the inside width consistent. Find the right size socket to roll in the channel. Where it stops, is where it needs tweaking.

All good times spent back engineering.

Good luck,
Roger