Window Wobble

[LSB4Me]

Hi Everyone:

I have a wobbly window (driver side) on my coupe. Removed the door panel and tightened the: (1) four nuts holding the mechanism to the door; and (2) the two (reverse threaded) nuts inside the vapor cover. On the latter, I was careful not to overtighten for fear of cracking the glass but still gave both nuts a turn or two. However, the wobble remains.

The entire back half of the window has a few mm of play. What am I missing?

Thanks in advance!

[LSB4Me]

Video of the wobble: https://vimeo.com/807745712

[Thoglan]

If it were me I'd just take the whole mechanism out and inspect it/put it back together. Make sure nothing is missing etc. Doesn't take too long to remove once the doorcard is off.

[LSB4Me]

I might have to go that route. But first …

Based on some additional research, it seems like my preload is off. This is adjusted not by simply tightening the e-tord from the rear, but also by tightening the front bolt though the exterior of the door in tandem.

To do the above, I have to remove my rub strip. Hoping someone here has faced this in the past and can confirm before I go any deeper.

[Thoglan]

I might have to go that route. But first …

Based on some additional research, it seems like my preload is off. This is adjusted not by simply tightening the e-tord from the rear, but also by tightening the front bolt though the exterior of the door in tandem.

To do the above, I have to remove my rub strip. Hoping someone here has faced this in the past and can confirm before I go any deeper.

Presumably you are talking about the 13mm nut on the glass?

I was able to just hold this in place with a 13mm spanner from inside the door skin, no need to remove the bumper strip. Then tighten the reverse thread e-torx.

[LSB4Me]

Presumably you are talking about the 13mm nut on the glass?

I was able to just hold this in place with a 13mm spanner from inside the door skin, no need to remove the bumper strip. Then tighten the reverse thread e-torx.

Precisely--the 13mm nut. I thought I had to remove the rub strip trim to access this. If not, that makes life a lot easier (and less risky).

Am I correct that the process is: (1) loosen e-torx (righty-loosey); (2) use 13mm spanner to pull window towards the inside of the car; and (3) while pulling the window close, tighten the e-torx (lefty-tighty)?

[Thoglan]

Precisely--the 13mm nut. I thought I had to remove the rub strip trim to access this. If not, make life a lot easier (and less risky).

Am I correct that the process is: (1) loosen e-torx (righty-loosey); (2) use 13mm spanner to pull window towards the inside of the car; and (3) while pulling the window close, tighten the e-torx (lefty-tighty)?

Shouldnt even really need to pull on the window with the 13mm spanner. Just hold the nut while you tighten up the e-torx. There's really not much adjustment in the position of the window. It just sits in a channel on the front and rear of the door, so you can only really slide it back and forth a couple inches and the e-torx bolts clamp down on the glass. There is a small amount of adjustment on the B pillar side of the glass with a little eccentric bolt piece that you'd see if you completely removed the mechanism, which adjusts the angle of the glass to get a proper seal against the door seal.

Other than that you can't really go wrong since the glass only goes in one way. With the glass wobbling like that the first thing I'd do is clamp down those e-torx bolts (make sure to hold the nut with the spanner so it's not spinning freely). And failing that remove and check what's wrong.

[LSB4Me]

Shouldnt even really need to pull on the window with the 13mm spanner. Just hold the nut while you tighten up the e-torx. There's really not much adjustment in the position of the window. It just sits in a channel on the front and rear of the door, so you can only really slide it back and forth a couple inches and the e-torx bolts clamp down on the glass. There is a small amount of adjustment on the B pillar side of the glass with a little eccentric bolt piece that you'd see if you completely removed the mechanism, which adjusts the angle of the glass to get a proper seal against the door seal.

Other than that you can't really go wrong since the glass only goes in one way. With the glass wobbling like that the first thing I'd do is clamp down those e-torx bolts (make sure to hold the nut with the spanner so it's not spinning freely). And failing that remove and check what's wrong.

Update: I wasn’t able to make sufficient (satisfactory) headway with a 13mm spanner, so I bought a bunch of deep socket, 1/2” drive, 13mm bits and went in through the door moulding on the outside of the car.

Some things of note:

1. The rubber o-ring (which I believe holds the tensioner / adjustment wedge mechanism together in a sandwich) was torn and sticking out from inside the sandwich. Not where it is supposed to be and not a good start.

2. The black plate directly under the 13mm nut was crooked, such that only one of the two teeth (the silver metal channels under the adjustment wedge mechanism that hold up the wedge apparatus and glass) was engaged. The outer edge of the black plate was wedged (pun intended) into the side of the other tooth/channel.

3. The 13mm nut free spins in both directions—meaning it turns but no resistance is felt/reached at any adjustment point … within reason.

Obviously this is suboptimal, but it is more information and a potential source of my issue: the rear adjustment wedge mechanism.

Rather than replace an otherwise operational regulator (new BMW units are $450), I am contemplating either: (a) buying a used BMW regulator and replacing the missing parts in my regulator with those from the donor unit; or (b) buying an aftermarket regulator—again, for parts. Leaning towards the former as it is the most likely to yield an apples-to-apples comparison.

Any alternate thoughts, tips, or tricks?

[LSB4Me]

Ok, I think I have it figured out. A small rubber o-ring tightens the metal clamp on the rear of the two adjustment mechanisms. Mine is broken.

If I hold the metal clamp together with my hand, the wobble stops. Thus, I am fairly confident (hopeful) that the broken o-ring is my problem.

O-Ring / Grommet Part No.: 64-50-8-369-241. Exploded diagram attached. O-ring is # 16.

I will update when the part arrives. What an ordeal.

[PipeUy]

Following this very closely, my driver door window also wobbles exactly like yours and I haven't had time to disassemble the door and check what's going on. Let us know if the o-ring fixes the issue!

[bagger]

Same - also following. Tried to tackle my somewhat wobble issue by tightening the four bolts and no joy. I actually did more harm than good because I went too tight and now two of the four nuts just spin with the bolt. Then while putting the door panel back on banged on the speaker grille and cracked that. Bad day in the garage for sure! Please keep us posted on the oring!

[LSB4Me]

FWIW, I have my o-ring on order, but wanted to share a photo that I found (in another thread, on another forum) regarding the placement and importance of said o-ring. See below.

It appears as though it holds the entire adjustment/tensioner mechanism together. Assuming there is play in my mechanism, this would explain the play in the window and the free spinning 13mm nut that isn't getting any purchase against the adjustment wedge inside the mechanism.

Also of note, the "hooks" shown below are the "channels" I referenced above in Post # 8, Bullet Point # 2.

[Pklauser]

LSB4Me did that oring solve your wobble? Trying to gather some intel before I take my door card off.

[lemoose]

Theres this part (4x) which is what should be sliding on the regulator rails. Theyre plastic so they just fall apart over time. Not sold separately but there is an ebay seller which makes/sells a replacement. I couldnt figure out how to take the regulator apart for installation though so i just looked for a used assembly with all 4 sliders intact.

EDIT:
link to ebay listing mentioned:

https://www.ebay.com/itm/334781721606

[LSB4Me]

LSB4Me did that oring solve your wobble? Trying to gather some intel before I take my door card off.

Sorry for the delay. The o-ring did not fix my issue. I replaced the entire window regulator with a genuine part. That did the trick.

Fwiw, it’s annoying to pop the card off but the job is pretty straight forward. You’ll benefit from an extra set of hands for 5-10 minutes when getting the new unit in place. Good luck!