Rear Window won't close completely - PeachParts Mercedes-Benz Forum

git0 · #1 03-29-2004, 12:02 AM

1992 300E

Hi guys

Left rear window won't go up completely. It stops about 1- 1 1/2 from the top. Otherwise it goes up and down fine - motor is ok has there are no abnormal noises i.e grinding - ithe window just stops and inch or two from the top.

I removed panel and removed the window lift. It sems ok - no broken pieces. Cables from the motor assembly appear fine as they are on their repsective pulleys and under tension. The guide piece is as shown on job 72-181 of the cd manual is intact. It seems that if it stops short then perhaps the guide piece should start a little higher on the guide rail ----- but -----

There does not seem to be any adjustment to be done on this rear window mechanism - or is there???

Can anyone offer any suggestions. Thanks.

Jim

G-Benz · #2 03-29-2004, 10:42 AM

That plastic guide piece doesn't actually "break" but rather "separates" into two pieces. It remains attached, but because it is no longer oriented on the rail properly, the window does not travel upward completely.

This is a common window mechanism failure among the W124-series models.

I don't rememmber the thread(s), but a few have mentioned that the part is available seperately for a couple of bucks. I lost my left rear assembly and then the right within a year of each other, and back then, the only solution was to replace the entire unit (about $140).

Good luck!

jrmd01 · #3 03-29-2004, 02:19 PM

It's called a window regulator guide jaw ($5 @ fastlane). G-benz is right they don't break off completely, but rather split in half. If you look and feel around inside of the the door, you may be able to recover the back 1/2 of the part, the other front 1/2 will still be connected as if nothing was wrong with it.

In my car that part broke and caused my motor to burn out. I ended up spending another $40-60 for the motor.

Change that guide jaw NOW before more damage is done.

jrmd01@yahoo.com

git0 · #4 03-29-2004, 02:43 PM

Thanks jrmd01 and G-benz

I did not even notice that but not recalling what they looked like new I will go home tonight and feel around inside the door.

I believe I recall the posts you mention - in that you haave to drill out the rivet in order to replace the guide.

Thanks.

haYnBenz · #5 03-31-2004, 01:28 AM

Hey git0,

Did you find your problem? Does your window go all the way up and then come back down on its own or not all the way up at all? If it is the former, maybe you have to reset or resunchronize your window switch. Do a search for "reset window switch" and you'll find much helpful info - as did I.

If the glass doesn't go up then it is prob the guide.

Best of luck!

git0 · #6 04-01-2004, 12:14 AM

Hi guys

well after a busy day at worl I took another look at the part.

Ha yen Benz- my window does not go all the way up and then reverse itself - it would come to within 1 - 1 1/2 from closing and then stop.

jrmd01 and G-benz

I looked inside the door - no broken pieces. So I look at the part itself as you suggested that it might split but not come apart. It seems this part is made of 2 halfs with the back cliping into the front. Other than the two halfs themselves they do not appear
to be any splits in the plastic. Any other suggestions.

the track itself does bend as if on the same curve as the window glass. I guess I could buy the guide part and drill the old out and rivet the new one in and see if that does it.

Right now I am open to suggestions.

G-Benz · #7 04-01-2004, 09:48 AM

I'm still betting on the guide part...it allows the rail to pivot appropriately are the window travels to the top.

Forgive me as I hadn't done this since 2001, so I can't remember the condition of my guide piece when I looked at it.

But when it fails, the rail gets hung up near the end of the upward trip (as you have witnessed).

Certainly the cheap route to go even if incorrect, but I'm 99.9999% sure that's the issue...

git0 · #8 04-01-2004, 01:01 PM

Thanks G-benz but no bet as my instincts tell me the same thing as you suggest. Its a neat puzzle as I eliminate what the problem can't be 1. the track is ok and 2. the motor runs fine so that leaves only the manner in which the piece in question moves up and down the slide.

As a last item I am going to rewire the unit outside the door frame so that I can observe the movement under power - other than that I am going to order the part - especially as it is inexpensive.

Meza · #9 04-01-2004, 09:25 PM

because it happened in my 190e. All you need to do is rotate the white guide 180 degrees from the sheet metal piece behind it. I can't remember CCW or CW. Go with the direction that extend the window travel your missing 1-2 inches. It will take some force to rotate and you have to slightly pry the metal plate to allow the plastic guide to rotate. Good Luck.
Meza

git0 · #10 06-20-2004, 09:26 PM

Well I finally diagnosed my problem. Symptoms were the rear window would not go all the way up but the motor was fine.

Turns out that it wasn't the window regulator guide jaw - as it was still in one piece. It was howver the thin aluminum piece that is rivoted to the window regulator guide jaw and locks into another piece. Take a look at the aluminum piece and its cut out and you will see where it fits into.

When secured, it keeps the window regulator guide jaw in the proper position but on mine the edges were bent up enough to allow the aluminu, to rotate out of position and this wa enough for the 1 1/2 to 2" difference where the window wasn't high enough to close. I bent the alluminum so that it locks into the mechanism and window now raises to the proper closing height.

Meza · #11 06-20-2004, 11:01 PM

Just what I posted.. I hope that helped.

git0 · #12 06-20-2004, 11:25 PM

It did - just took awhile to figure out what you meant. Thought you meant just the white reg. jaw. Thanks for the help.

Meza · #13 06-20-2004, 11:28 PM

It took about two hours to figure it out. My rear driver side was bad and taking the door panel out wasn't much help. I am glad everything worked out fine.
Meza