I took my 968 to the local Dealer today to have a tech look at the passenger side window. It fell down into the door a few weeks back. I removed the inside door panel...........looked to me like the metal ball ends at the top of the "Scissors" assembly that raises the window up had popped out of some sort of now missing plastic or nylon slider.

The tech who looked at it determined that that was exactly what had happened....he fished around in the bottom of the door and found part of one of the original plastic parts.

They are actually a plastic Roller that snaps onto the scissors assembly ball ends and allow the ball ends to smoothly roll back and forth in the tracks provided at the bottom of the window assembly.

This is the identical problem that most 126 series S class Mercedes experience with time. The fix was to buy a new $250 dollar regulator until an enthusiast took time to engineer a new nylon slider block (that he sold for $10) that could be peened onto the regulator after the original one was drilled out and removed.

Anyone know of a similar fix for our 944/968 cars???? Anyone know if there is an off the shelf part available that makes a suitable substitute for the OE Roller??

Brian Collins

 

Brian, I searched all over and finally went to a cabinet maker hardware supply shop (try Home Depot!) and looked for something that was similar in size, etc from drawer slides! Yep, found a delrin (very hard slippery synthetic) "wheel" that costs something like 50 cents each!! IIRC, I had to drill them out a little and then figure out a way with pop rivets to hold it all together with a spacers etc and still get it to spin. It works like a charm - not the "prettiest" solution, but heck, it works, it's hidden, and cost less than a buck!

The other option is to buy a regulator off a parts car - I've bought a spare for each side as I now have 3 of these cars around the house and figure that sooner or later, I'll have the same issues again. Problem is the plastic parts on some of the 944's are now 20+ years old and pretty brittle.

Yep, I had the same problem with my 126 S Class years ago with that plastic block slider, and again, figured out a way to bypass the parts counter!

 

Randy, any chance of more details on how you did the roller, spacer, pop rivet fix...............we could probably all benefit from this..............probably something that should be permanently archived.

Brian

 

I should have taken a few photos.... it was pretty easy actually. All done with hand tools as I was too lazy to run around to the drill press etc.

The DS window on my son's low mileage 85.5 944 NA fell into the door one day. When I removed the window regulator mechanism (not too tough, just a lot of hardware), it was pretty obvious that the OEM black plastic "wheel" had disintergrated due to age. The only "trick" when riveting it together is to make sure the new "wheel" spins easily. There are a few ways to do this with paper shims etc that you remove after you "pop" it all together, but the wheel must spin.

I called the local dealer etc and finally decided that it was a similar situation to my MB 126 a few years earlier. I went around to a few cabinet shops and figured out that drawer hardware goes through a lot of cycling over the years so that might be the lead. I found a source of drawer slides that were pretty cheap and the then sourced the rollers that were about 4mm thick and the correct diameter.

I found the loose roller wheels in Home Depot (yep!) for something like 25 cents each, so it was a cheap solution. I just drilled these rollers out to fit a 3/16" x 1/2" alum pop rivet (cause I happened to have a few in the tool bin) and used a few thin washers on one side to keep the new wheel "proud" of the regulator arm. Drilled out the old OEM wheel, pop riveted it all together. The only problem was they were slightly "cupped" rather than a consistent thickness. But they were Delrin, and that is pretty durable stuff.

Reinstalled it all, and presto, it's been working like a charm on the oft used DS window for 2 years now. I'd do the same again rather than spend a fortune to get the complete arm mechanism (I never did find out if you could just buy the little black OEM plastic wheel).

It took longer to remove the arms than to do the repair! Pretty easy actually, and since you don't see it at all, will not offend the purists! As I stated above, I did take the opportunity to buy 2 good arms off eBay - more for the motors than those wheels though. Good luck! It's a pretty easy DIY solution.

R

 

Randy, have read your description a couple of times. What is it that you are pop riveting together and what are you shimming?

I don't have an original roller/wheel to go by or use (I looked in the bottom of the door and found only one half of one roller)

I'm trying to picture this and so far............no pic coming up in my virtual brain veiwing screen.

Sounds like you somehow maybe pop riveted the original wheel onto the new delrin roller perhaps??

or did you pop rivet the broken original roller together....if so,.....can't picture how this might be done.

You also mention drilling out the center of both rollers to maybe accomadate a big rivet.......................how does all this fit onto the regulator ball end?? or are you removing the ball end welded onto the regulator arms perhaps then using the large pop rivet to pop rivet the new roller on the regulator arm using the hole left by removing the ball end??

Brian

 

Randy, I think I may have figured this out. You must be drilling out the arm of the scissors lift to remove the ball end, then riveting your plastic/delrin roller onto the arms of the scissors slipping a slotted spacer in between the new roller and the arm momentarily prior to pulling the rivet tight,....then, removing the slotted spacer will create some "free play"



Is that the idea??

If it is, cool, but,......still don't understand how or why you are riveting the old broken roller to the new one.........................or maybe, you used the original roller to hold onto the ball end and riveted the two broken halves of the old one against the new one which is now the one that will roll in the track, with the old broken one now running outside the track??????

Is that it??

either one close??

Brian

 

Sorry for the delay Brian - yep you got it right. Drill out the ball end. Find a Delrin "wheel" from quality cabinet hardware, and "pop rivet" it in place to replace the ball pin, etc. The washers act as spacers to establish the clearance for the guide that is fixed on the bottom of the window glass. It all works surprisingly well - does not look the best, but it works. And no worries about the tolerances either - the OEM wheel / ball end was designed for lots of deflection tolerances to accomodate real world use. Bottom line, it works and is simple. As I stated before, 2 years on, and the DS window still works like a charm. Sorry I don't have photos, but I just hate dissassembling that window having done it several times.

Just reread what you wrote above - no need to re-use the old black OEM plastic wheel or the ball joint - all that gets turfed. No need to do anything other than use the new Delrin wheel - the pop rivet takes the place of the ball joint. Does this make sense now?

Good luck!

 

Randy, spent a few hours yesterday to make the trip to Home Depot with no results then thought maybe you had found them at Loews and just recalled it as Home Depot, so checked there as well.

Asked a few different people in each store and did a very thorough search in person and did not find the loose drawer rollers in either store. They did have complete drawer slides with rollers attached (about $16) and I did also find some shower door rollers that were about .75" in diameter (the original window regulator rollers are .67" in Diameter) and attached to a metal center hub that was threaded for a small screw.

Both stores had the same selection with no separate rollers.

You sure it was Home Depot??

Brian

 

PS....the rollers on the complete drawer slides also were about .75" in diameter.

Both