S124 Electric window jerky

[Rob77]

My driver's side window sticks at the same point, opening or closing.

I'm taking that to mean it has missing gear teeth and needs a replacement regulator but can keep the existing motor, right?

That being the case, do these differ or can I buy any 2nd hand replacement from eBay, provided its for the correct door?

 

[hotrodder]

What point does the glass stick at? Worn/stripped regulator teeth typically happens at/around the closed position, they don't get sticky but IME get a little noisier at that point and then, shortly afterwoods, you get a bang (as what's left of the teeth gives up and the gear on the motor slips over them) followed by a motor that whirrs away in either direction when the button is pressed but glass that won't move and is almost, but not quite, fully closed

If the glass is jamming/sticking and the motor stops unless you give the glass a helping hand then it probably needs adjusting or something else in the regulator (like one of the sliding nylon blocks) is more likely to be the issue?

Saloons and estates share the same regulators and motors, so yeah just need bits from the same door. Motor bolts to the regulator and the whole lot then bolts into the door. Coupes and cabriolets are different

Bear in mind that a lot of used regulators are gonna be at least half knackered by now but some breakers still happily sell them as working just like they often list used bits on the bay for more ££ than they cost new from MB... http://i.ebayimg.com/00/s/MTIwMFgxNjAw/z/O0UAAMXQC-tTD1eq/$_57.JPG for example. Bottom of the pic can see two teeth have almost completely gone.

 

[ringway]

Good advice above, however, a liberal dosing of silicone spray in the side channels will enable the glass to slide more easily.
I have to use this on the 210 drivers window around every 6 months and the results are excellent. Wipe off any overspray on the glass.

 

[merc85]

i had this on my last w124, The regulator was repaired by adding/welding the missing teeth

 

[flango]

Also on these the channels rot and a jerky window is usually the first sign so check for the old tin worm behind the door card.

 

[optimusprime]

All good advice ,done it been there .Nice to know about the silicon spray .Next on my list .

 

[Rob77]

What point does the glass stick at?

Thanks everyone for the hints and tips. Much appreciated.

The car's in the garage having some welding done and the front suspension rebuilt so I'm going from memory.

When I bought the car around 5 - 6 years ago, it came with an invoice for replacing that item and I doubt it was replaced with an MB part.

Anyway, right from the start, it tended to stick in the open position. So I'd open the window to swipe the security gate at work and, when I went to close it, it would stick on first press of the button. Second press would work fine.

Recently, that point has changed so now it gets to an inch or so from closed then it stops. I release the button then press again and it works fine.

I haven't noticed any weird noises at all.

I'll be collecting the car tonight then it's going back in again next week to have the rear suspension done. I'll check if what I'm saying here is right.

I'd like to get this fixed though and, if it meant buying a part to hand to the garage to install, I'd like to do that.

 

[hotrodder]

It's sounding like maybe the glass is meeting enough resistance for the motor to stop as it thinks* it's closed? As said having a look behind the door card is the first step and will also let you see how much wear there is on the regulator teeth. A while back someone on the 'other side' had a kinda similar problem but the glass needed supporting by hand to finish closing. IIRC it was one of the sliding plastic guide blocks that broke which was available seperately for peanuts

If the teeth are looking pretty worn/hooked then 124 720 0446 B: WINDOW LIFTER RIGHT for Mercedes 124.092 (320TE / E320) will get you the MB part number along with that of a few pattern suspects. New from MB the list price is £170. I don't think you'll find many (any?) other sources for genuine (Brose was one of, if not the only suppliers) new ones. Various pattern examples here Spare Part 1247200446 some of which may be better quality and/or cheaper than eurocraparts or the bay

Destructions for door cards and window stuff 72 Doors ETA, the top clip on the mirror cover is small & fragile


* more resistance = the motor pulls more amps and once it reaches whatever the current limiting threshold is it's shut off until the button is released and pressed again

 

[Rob77]

That's great, thanks for the further details.

I've had a play around with the window and I was wrong. When it sticks, I don't need to let go the button.

The window is opening (or closing) and, at the same position, it sticks for a moment then carries on moving.

When it sticks, it does make a noise but not very loud.

I'm thinking missing teeth now. And thinking maybe the answer is a second hand replacement from Germany where it'll have had little use being on the "wrong" side.

 

[carat 3.6]

If it's only the regulator teeth worn away, have them welded up and re-cut.

 

[Rob77]

If it's only the regulator teeth worn away, have them welded up and re-cut.

Thanks, that's a possibility. The car's back in the garage to have the rear suspension rebuilt now and the chap there does some super welding (he's already done the inner front wings and a few other smaller parts). He would be well capable of reforming the teeth but I would've though a second hand unit from Germany would be better/cheaper long term?

Anyway, I've asked him to take off the door card and see what's what first and let me know.

I'll post with an update once it's sorted

 

[hotrodder]

If the place doing the work are happy to put a tack weld on what's left of the origional worn teeth and grind/file them to shape i'd take that over a used replacement personally unless you can inspect the one your buying personally... while a passenger side regulator from a LHD drive car might have seen little use it's a gamble. FWIW when i bought my 320te on of the listed faults was a non working passenger window (motor wirring away, glass not moving). I assumed the drivers side had already been fixed/replaced once but nope, that packed up a few years later and it was an orgional Brose regulator in there that hadn't been welded previously

All that said if the glass sticks momentarily and then carries on i promise you the teeth haven't been been stripped yet. They might be very worn but that will not cause the glass to stick and then free itself without some horrific noises (seriously, when you experience one let go it makes you jump) coming from the door as the gears skip over each other

 

[Rob77]

Thanks to all for the help and advice.

Just to close this one out, it turned out the teeth were well worn.

I got a second hand (Brose) unit from Germany and its all working as it should now.