Mono wiper
 

I'm trying to help out a neighbor with his 90 300D. It looks like the head on his mono wiper is out of wack. The in out won't stay timed with side to side. I read the article at MBZ.org http://electric.mbzarticles.org/wipers/ but this head doesn't have clips holding it together instead there is one all but inaccessable screw. Does anyone have some information on disassembly or replacement.

Find a used one, its not fixable.

Thanks Steve,
Any pointers on removal?

My only comment is that it is easier than it looks. I don't do disassembly work anymore so I not much use on the instructions for such. I know that the guys in the shop have them out before I can look the parts up.

I'll put some seasoning on my foot because it always ends up in my mouth when I contradict Steve -

You can take a part an extending wiper assembly. Basically there's a circlip at the driven end of the shaft that keeps it together. Inside you'll find that the shaft drives a gear that rides on a cogged rail on the inside periphery of the case. I suspect the wiper is out of time because the cogged rail is missing some cogs. Alternatively the gear can be missing some teeth but I believe all 124s use a metal gear vs nylon or fiber cogs. [whine] This is unlike the 140 that uses a nylon gear with a weak splined fit on the shaft. [/whine]

I've looked at a few extending wiper mechanisms in my search for a replacement gear (no other MB has the same gear as a 140) and I've found that all cogged strips can be replaced. Finding a replacement is the problem. You can get a used wiper assembly, but if it works, why take it apart to fix yours? Which I guess is Steve's point :)

BTW, If you remove the gear or coged rail, you can limp along with a non-extending wiper arm.

Sixto
95 S420
87 300SDL