911 electric window rattle -- the fix!

[logician]

The window in my '86 930 has rattled since I got the car. It sounds like there are a bunch of loose parts in there that are about to come apart. Apparently, this is a common problem, as I found numerous reports of it on PP. An informal poll of my Li track friends indicated that 50% of the 911 Carreras ('84-'89 vintage) had similar problems.

Well I found how to fix the rattle in my car, and I think this fix might be generally helpful. I started by taking the inside door panel off to expose the window regulator. Here is a picture of the window regulator through the access hole in the door sheet metal:



The regulator has two horizontal rails, one attached to the window glass, and one attached to the door. Then there are two crossed pieces that have rollers that engage inside of those rails. I found that one roller seemed really loose in the rails, and if I tapped on one with my finger, I got the rattling sound coming from the cross pieces:



The solution was suggested to me by my mechanic (Alan at The Stable in San Francisco). The trick is to adjust the lower rail, the one attached to the door, so that the loose roller is seated with some weight on the lower rail, instead of just hanging in the air. Before making the adjustment, put the window all the way up so that it seats into the window frame. There is an allen screw in an elongated hole that you can loosen to allow adjusting the angle of this rail:



I surmise that what probably happened was that the window glass was replaced at some point, or the window frame was adjusted due to some body work, and the regulator rail was not adjusted accordingly. Actually, the rail controls the angle of the window, so it is possible to over adjust it, and cause the window to bind in the frame. So after adjusting the rail angle, I ran the window up and down several times to make sure that it operated smoothly.

My 930 is now much more enjoyable to drive!

-Juan

[on-ramp]

great, thank you...i have the same problem on my 83sc...time to get crankin'

[Speed Buggy2]

Thanks - project for this Saturday. Cheers

[Sonic dB]

Nice post. You are a credit to this forum for sharing this.

[RoninLB]

the top of the glass where it meets the top of the frame should be square across the top. I guess it could be fine tuned..
Good thread info.

[logician]

Originally posted by RoninLB
the top of the glass where it meets the top of the frame should be square across the top.

Good point. I'm assuming that the window frame is adjusted right, and that the frame conforms to the shape of the glass. If that is not true, the maybe you will need to make other adjustments to the frame.

Assuming the frame is adjusted right, then when you put the window all the way up, it will seat against the top of the window frame. When it seats, it will allow some of the rollers to lift off of the rails. That's why the rattle tends to happen most when the window is all the way up. If you lower the window a little, then the weight of the window is supported by both the front and back rollers and so the rattle tends to decrease.

Note that I edited my instructions to say that you should raise the window all the way up so that it seats against the top of the window frame. I forgot to say that previously.

-Juan

[logician]

So did anyone else have success fixing their window rattle with the procedure described in this thread?

-Juan

[Glasgow 911SC]

I might be trying this at the weekend so I'll let you know.

[CrossT]

I have a similar problem, but my driver's window regulator rattles when the window is anywhere but fully up or fully down. It is annoying and I would like to be able to drive the car with the window part way down. I've been assuming I'd just have to replace the regulator and haven't done anything about it. I will try messing with it this weekend 4.5 days off

todd
86 coupe

[dram]

My 87 is that way also. No rattle if it is all the way up or all the way down, but anywhere between it rattles.

Don

[Glasgow 911SC]

Mine rattles just about everywhere apart from fully up.

[CrossT]

I think in my case the culprit is the pivot in the center of the scissors. Maybe just a load of grease would do it.

todd
86 coupe

[logician]

Originally posted by CrossT
I think in my case the culprit is the pivot in the center of the scissors.
86 coupe

I bet it's the adjustment, not the pivot specifically. I originally thought the same thing as you about my window regulator. Tapping on the scissors at various places, including the pivot, would make the rattling sound.

However, it turns out that proper adjustment eliminates the rattle because it puts weight on the pivot and other components on the scissors, so they are no longer so free to move around.

-Juan

[GrindingGears]

As the others have said, my window rattles in any position, but mostly when in between fully up or down. I've taken apart my door a number of times to find out where the noise is coming from and it is indeed the same rail you speak of. Grease won't do schit, I've even tried wrapping cord and metal wire around the roller to prevent noise, but it always eventually comes back. Will try this soon and report back, I hope this is the fix, there have been many posts on this issue

[niner11]

Juan, I have the same type of noise comming from the same area of my driver door. Just wondering if the fix that you came up with worked in the long run.

Thanks

[logician]

Niner11,

The fix is still working great!

-Juan

[niner11]

Thanks Juan, that did the trick. Doesn't even make noise when I close the door.

[Jon Hile]

Thanks for the tip Juan. A little tension on the door rail and the annoying rattle went away for good.


j

[RoninLB]

the glass has outside & inside rubber at the top door edges that hold the glass.

[RickM]

Good info.

I get a rattle on my DS door when I close it. Time to open up.