Something went "POP" in my door - PeachParts Mercedes-Benz Forum

Jeremy5848 · #1 11-28-2006, 06:09 PM

I lowered my driver's side window to get the mail this morning; just as the window reached bottom, something made a distinct "POP" inside the door somewhere.

Now, although I can hear the motor running smoothly when I press the switch UP or DOWN, the window won't move. I did a search on the forum but can't find anything that specifically mentions this problem.

Given the time of year and all, I'd really like to have the window up rather than down. I'm going out to take the inner door panel off of the door, following DieselGiant's excellent pictorial (thanks, DG!). What am I likely to find when I get in there?

Jeremy

Biodiesel300TD · #2 11-28-2006, 07:03 PM

Sounds to me like the gear on the motor broke off, or you broke the teeth off the mechanism.

Jeremy5848 · #3 11-28-2006, 07:06 PM

Thanks to DG's pictures, I was able to get the door panel off without damage.

Inside the door, I was able to lift the window back up to the top, so at least the immediate problem is solved. When I press the window switch, the motor runs (I can hear it, but nothing, including the big metal gear) moves. Will I have to remove the regulator to see what has broken?

pawoSD · #4 11-28-2006, 07:06 PM

You may have just popped the little nylon slider that allows the window mechanism to move, its a $2 part from the dealer. It happened on a rear window on our '83 last summer when we put the window down. So far none of my windows have failed....and I've had my car 3.7 years!

My right rear door even got smushed inward when I was sideswiped...the window jumps once when going down, but still works fine.

Jeremy5848 · #5 11-28-2006, 07:18 PM

Seems to me that, if everything were connected, I should not be able to move the window up and down by hand...but I can. If something has broken (the "POP" that I heard that connects the window to the regulator, then the regulator would run until the big gear ran out of teeth.

I was able to move the big geqar by hand until it apparently reconnected with the motor. Now I can make the big gear go either way with the window switch but the window doesn't move.

So what is this little nylon slider?

Jeremy5848 · #6 11-28-2006, 07:33 PM

I got some light and a mirror into the door so I could watch what's going on. I can now see that the X-mechanism that moves the window is connected to a long metal arm. That arm comes down next to a big gear. This gear doesn't make a complete circle, it is only a segment of a circle. It looks to me that the arm is supposed to move up and down, carrying the window with it, as the gear is rotated by the electric motor. If this is so, then the "POP" that I heard was the breaking of whatever part connects the gear to the arm. Is that part replaceable or do I get to buy a whole regulator?

#7 11-28-2006, 07:48 PM

Quote:

Originally Posted by Jeremy5848

I got some light and a mirror into the door so I could watch what's going on. I can now see that the X-mechanism that moves the window is connected to a long metal arm. That arm comes down next to a big gear. This gear doesn't make a complete circle, it is only a segment of a circle. It looks to me that the arm is supposed to move up and down, carrying the window with it, as the gear is rotated by the electric motor. If this is so, then the "POP" that I heard was the breaking of whatever part connects the gear to the arm. Is that part replaceable or do I get to buy a whole regulator?

Take a look at these photos of the regulator:

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1CQ0J3JZ41YE16BZCY&year=1985&make=MB&model=300-DT-001&category=All&part=Window+Regulator

maybe this will help you see what broke.

Jeremy5848 · #8 11-28-2006, 07:48 PM

My mechanic says that, when whatever in my window regulator breaks, the arm or the gear or whatever usually bends a little. It's not enough to see, he says, but puts strain on other parts and the regulator is never the same after that. He recommends replacing the regulator. Given that this is the heavily-used driver's window, his advice sounds good. Do you agree?

Jeremy5848 · #9 11-28-2006, 08:08 PM

Quote:

Originally Posted by Craig

Take a look at these photos of the regulator:

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1CQ0J3JZ41YE16BZCY&year=1985&make=MB&model=300-DT-001&category=All&part=Window+Regulator

maybe this will help you see what broke.

Thanks for the reference...here's a picture of the regulator for the right side (the catalog doesn't have a left side picture). I have labeled the picture and added arrows to show what moves and what doesn't. As I understand it, the arm and the gear should move together. Mine do not.

#10 11-28-2006, 08:32 PM

Quote:

Originally Posted by Jeremy5848

Thanks for the reference...here's a picture of the regulator for the right side (the catalog doesn't have a left side picture). I have labeled the picture and added arrows to show what moves and what doesn't. As I understand it, the arm and the gear should move together. Mine do not.

Yep, there is some kind of a pin that holds the arm to the gear, I don't remember exactly what type. I would just remove the entire assembly and take a look. You can use a piece of wood to prop up the window while you have it removed.

benzforlife · #11 11-28-2006, 08:33 PM

not sure if this was already asked, but was the plastic slider intact ?

Jeremy5848 · #12 11-28-2006, 08:39 PM

Quote:

Originally Posted by benzforlife

not sure if this was already asked, but was the plastic slider intact ?

Asked or not, I wouldn't be able to answer the question until you tell me what a slider is.

Still new after all these months.

Jeremy

hey_allen · #13 11-28-2006, 09:05 PM

The plastic slider (that seems to fail relatively commonly, at least in 20+ year old cars..) is the piece that joins the silver colored X linkage in the middle of your picture with the right end of the gold colored part.

In your picture, it's the little white colored bit between the gold and silver arms in the bottom right.

(This is assuming that I haven't completely mixed up all the information I've been trying to absorb over the last few months of digging through this forum, trying to fix my car!

)

Jeremy5848 · #14 11-28-2006, 09:45 PM

Quote:

Originally Posted by hey_allen

The plastic slider (that seems to fail relatively commonly, at least in 20+ year old cars..) is the piece that joins the silver colored X linkage in the middle of your picture with the right end of the gold colored part.....

Ah! Thank you -- the slider is OK.

I'll pull the regulator and see what I can see. Maybe there's something I can replace. It would be nice to save $120.

By the way, I noticed a small kit of parts called a "Window Regulator Bushing/Repair Kit; Lifter Slider Repair Kit." I wonder if what I need is in there somewhere? The part number for the kit is 123 720 01 14 and it sells for about $10.

#15 11-28-2006, 09:55 PM

The problem should be pretty obvious when you get it removed. I was actually able to straighten out one that was bent on my 240D (causing the gear to skip). You may also be able to find a good one from a junk yard if you can't fix it.