1976 Mercedes-Benz 230.6 Window Regulator Replacement

Today's patient, the 1976 230.6, this guide will apply to any W114 or W115 from 1973 onwards (facelift)

Remove the two phillips #2 screws

Pry out the black plastic cup behind the door lever, using your pick or flat-head screwdriver

Then remove the single phillips #2 bolt, taking care to retain the lockwasher

There are a total of three phillips #3 bolts holding the handle to the door, two at the bottom, and a single one at the top

Your phillips #2 screwdriver will work fine here, but you could use a #3 if you want

For the top bolt there is a chrome trim covering it. You'll need to pry back gently - using a pick or small screwdriver so as to leave it undamaged

You've removed the two surrounds, and the door handle

There are two metal garnishes above each lower-leg of the door handle, I like to arrange them so I know where they went - for later reassembly

Looking down almost behind the window winder handle, you can see the trim panel has a bent-metal clip, the trim also acts as the locking-clip to hold the handle on

First push the trim panel outwards toward yourself

Then it slides away from the hub, towards the knob which you hold to rotate the handle

The interior door trim panel is held in place by a series of push-pins around the edge of the panel, you can pry them out using a plastic trim tool, or like I did here with a small prybar and rag

To avoid damaging the trim or the door, try to get the pry tool as close as possible to each clip then gently pry until it pops out

The trim panel separates below the top portion, so the lock-knob and window seal can remain in-place and undisturbed

Remember the trim panel is very-fragile and made of particle-wood, so handle it gently and place it out of harms way while you're working on the door

Peel back the vapour/moisture barrier plastic, mine was removed before, so the original glue was gone, I had some spots of double-sided tape holding it in

I just fed it through the partially-open window to hold it back, but if it's windy it might be annoying

We're trying to gain access to the door interior

My new part (1157251102) looked so full of promise with it's blue genuine parts label, and it's shiny metal it's manufacture date stamped 10/1987

However the installation was about to take a turn for the worse, I didn't realise at first, naively thinking a genuine part would just bolt-on

It turns out my new part didn't have threads tapped in the four bolt holes!

Can you believe it!?

So with a bit of cursing, I dragged out my tap and die set

If you get lucky you won't need to tap the holes on your replacement regulator

The arm that attaches to the bottom of the window uses a pin with clip and special washer

It's a bit fiddly since you can't see it easily, mostly you'll be working by feel, the clip slides into a groove machined into the tip of the pin

There is a rectangular plastic bushing that slides in the window-bottom track, it fits over the pin first

Then the pin and bushing go through the track

Then there is a plastic slightly-conical flat washer with a metal star-shaped washer that fits over that

Then at the very tip of the pin - facing into the door, there is a spring-steel clip

I used a pick and a flathead screwdriver and a pair of needlenose pliers and a bit of cursing to get it out and back in

NOTE: the window drops after you pull out the pin, since nothing is holding it up - I put a small prybar in place to hold it up, but you could also use a piece of wood or whatever

There are four bolts (circled in blue) holding the regulator to the door, they are all 10mm head bolts, but the top two are longer

I used a 10mm deep socket on a 1/4 inch ratchet, but any 10mm wrench, spanner, or socket should work

in the second picture you can see the gear-quadrant of my old regulator hanging down, it's supposed to be up engaged in the winder gear teeth

It was at this point that I realised I could not get the old regulator past the window vertical track...

Notice I'm using a short prybar to prop up the window now (since otherwise it drops down) you could use a piece of wood or some other tool as well

Since you can't get the regulator out past the window track, it has to be detached temporarily

It's held on by two 10mm bolts, which have fancy dimpled flat washers, and lock washers, I've circled them in green in the picture

Remove those two bolts, which should give you enough movement to push that window track forward off the window a bit, then into the door a bit deeper

At this point it should be possible to pull out the window regulator, angling it as you go to avoid jamming on things

As I mentioned in step 9, I was punished by the lack of threads in my new window regulator

So I broke out my tap and die set, and checked the bolt thread pitch, which was metric M6 x 1.0

I didn't notice until I'd already slipped my new part into the door... I actually pulled it back out of the door to tap the four holes

If your part also has a lack of threads in the holes, be sure to check it before you've put the clip through the pin, and reinstalled the track bolts etc

Install several of the regulator bolts (remember the top two are the long ones)

Don't tighten them yet

Grease up the window bottom track and bushings before assembling

The bushing clip is pretty hard to get on - enjoy that

After you're happy with the placement tighten the bolts

Then remember to put the vertical window track bolts back in too - they have the funny dimpled flat washers (be sure the window glass is in the track)

Follow the steps backwards to reassemble the door