1978 vent window 4-door Town Car banging noise

[78_towncar_460]

Hello, I don't use the windows often, but for many years, the front passenger side window has made a loud bang sound once the vent window goes all the way down. It operates smoothly up and down. Are you aware of any sort of bushings in the door that are to prevent this from happening? It is as if there is tension on part of the assembly and once that vent is finished moving to the down position, something slams into place and creates that noise. Looking into the door during operation, I don't really see any sudden movements or jarring motion. Has anyone else experienced this before on a 70s Continental? I have the manuals and the exploded diagrams don't really help.

[TonyC]

Only a wild guess...but maybe there is a missing stop block. I'm thinking there should be a rubber block mounted in the door at the bottom of the window's travel, to cushion its bottoming and prevent the thudding you are now hearing and feeling. If there is supposed to be one there and it's missing...they can fall out on odd occasions.

---Tony

[78_towncar_460]

I'll have to study the diagram in the manual and check part for part for missing items. Nothing was sitting at the bottom of the door, but someone else could've pulled it over the last few decades.

[Dan Szwarc]

I think this is actually a lubrication issue.

My 77 did this drivers side only. I never got around to diagnosing it, but you can use the other side to compare.

[78_towncar_460]

[youtubes]https://www.youtube.com/watch?v=Y_RbpQUwgJI[/youtubes]

On my video above, the camera microphone autolevels, so you can tell that it is fairly loud as the volume takes a second to come back to full. I had used lubriplate in the door about 15 years ago. The grease that was in there was still good, but I redid it anyways. There are some spots that I need an actual oil can (as the manual mentions "mini-vent lubricant"). I don't have one, so I tried to coat them as best I could.

This guy has a video that I believe shows a similar problem, although it is not what he is after. You can see that guide pin that sticks out--it sort of pops into place and makes a noise at about 33:26. I wonder if there is supposed to be a bushing on that thing?

https://youtu.be/KWeVeoRtASI?t=2002

[Dan Szwarc]

I have a 79 power window mechanism in my attic (I think) that I bought to figure this problem out.

I wonder if I’ll have time to pull it out and wire it up to move the window mechanism….