Window rattle, it sort of jumps

An odd sort of rattle has started happing with one of my windows that I can't figure out. When I hit a bump the window sort of jumps in it's track. It sounds like the door is rattling, but it's the window doing this bounce thing. Thought it was the whole door for a while till I rested my arm on the window, an inch up, and noticed it went away. I've looked under the door panel and can't figure out why the window would do that. Wondering if there is some clip that has fallen off that holds the window and frame together?? The windows on both sides have the same amount of play in the crank (maybe 30 degrees).

Any ideas on this? Thanks. tom

OK, Tom - I'll bite, if only to get someone else' opinion...
My guess would be that the frame supports are loose. Remove the door panel(s) and have a look-see. You might find the track needs tightened. Maybe the winder mechanism needs cleaned/greased/serviced in some other way. You have a RB - I have a '71 CB GT - but I'll bet the "guts" are the same.

Pull the door panel off (easy job) and it should be obvious where the problem lies. Check all the seals in the tracks and check the winder mechanism for play.

One more thing to check is the felt pad the window rest on at the bottom of the door. They can rot and fall off causing a rattle. If the glass is moving something's loose. If you need the felt let me know I have some grey jute padding close to the orginal material that works well. I'll toss some in the mail to you.
Bill

Ha..

I started hearing a rattling sound as well, from the driver side door a week ago. I tried sticking my finger in the slot to try to hold the window stable, still rattled, I then thought it may be the mirror.. held it.. still rattle. This afternoon, I read this post, so.. on the way home tonight, that same annoying rattling, so I roll the window up about two inches.. and.. no more rattle.
Now, I guess I need to take off the door panel this week.

Thanks for a timely posting.

Paul

Thanks for the feedback guys. I did not spot anything odd the first time I looked in the door. That bottom felt pad does sound like a likely culprit Bill. I may take you up on the offer. Paul let me know if you figure out your window problem. With mine if I put a finger on top of the window, the rattle is gone, otherwise it sounds like the door is falling off. Mine came on suddenly too. tom