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1992 500SL
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52 Posts
Discussion Starter #1
Since i joined this forum some time ago it's has been very helpful to a DIYer such as myself. So after i encountered an issue with my wiper transmission and had difficulty finding a good "how to" on fixing it I thought i would give back and do my best to describe how i fixed the issues.

The issue came up when the wiper transmission started extending the wiper in the wrong places, ramming it into the side of the A-pillars and getting stuck. I removed the wiper assembly and attempted to get the shell off the transmission and discovered I have a metal one, not a plastic one that just pops off if you pull hard enough. So after much fiddling I think I found the easiest way to access that cover.

First remove the assembly from the car. There should be 3 10mm nuts and 2 8mm screws. The plug for the motor is located under the electrical panel next to the motor on the passenger side of the car (my car is a US model by the way). Once The assembly is out of the car on the back side of the assembly there is a 17mm nut on the transmission shaft and a 13mm nut on the motor shaft. I removed both, but you may only need to remove the 17mm nut.



Once these are off both of the whole back arm will pop off. Both shafts are toothed and tapered where the arm makes contact so it will take a considerable amount of force/leverage to get it to move. Be careful not to push on anything that can bend.



After you have the arm removed there will be one small snap ring on the shaft. Once this is removed the transmission will come apart. Note be careful that snap ring has allot of stored energy compared to it's mass, meaning it will go flying across the garage never to be seen again if your not careful... as i wasn't. I did find it but it took me a solid half hour of searching.



Now that the transmission is apart there are 3 screws on the back of the cover that can be accessed. Remove those and it will fall right off. Defiantly a huge pain to get to but that's the only way to as far as i can tell.

Once i had the transmission apart i found the root of the problem. The half moon gear had disintegrated rendering it completely useless. As a temporary fix i zip tied the wiper actuator in the retracted position so the wiper is still usable. Not a good idea to drive in florida without a windshield wiper.




Assembly is the reverse of disassembly. A few things to note. Position matters on the transmission shaft and motor shaft. Do your best to put them back in the same spot you found them. If it's off your wiper will rest in a different spot. The same goes for the transmission gears, the actuator is retracted at top dead center so make sure you put the gears back together accordingly.

A long post but i hope it's helpful to someone in the future. Feel free to ask questions and i'll do my best to help.

Cheers

-Max
 

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1999 SL500 Sport, Black Opal Pearl, Helios Leather, Pano roof, AMG Aero2 18"Split Rims, Rear Seats
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1,212 Posts
Thanks for the write-up I am sure others will benifit from your effors in the future.
I am sure you are aware that the gear can be had as an after market part, a quick google will find several sellers if not. Price seems to be around $90, a lot for a bit of plastic
 

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Premium Member
2015 Jaguar XF R Sport Twin Turbo, 1992 500sl Pano, 1999 CBR 1100XX, Super BlackBird, Jaguar X Type
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4,818 Posts
Thanks Max, my 92 is the same type. Can you expand on the removal from the car process? What needed to be removed to access the bolts to get the motor out etc.

Cheers!
 

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Registered
1992 500SL
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52 Posts
Discussion Starter #4
Thanks for the write-up I am sure others will benifit from your effors in the future.
I am sure you are aware that the gear can be had as an after market part, a quick google will find several sellers if not. Price seems to be around $90, a lot for a bit of plastic
I am aware, i already have one on order. I just put in the quick fix in the meantime because of florida weather which changes every 10 minutes. Even without the gear the wiper still covers the majority of the windshield, it's still very usable.

Thanks Max, my 92 is the same type. Can you expand on the removal from the car process? What needed to be removed to access the bolts to get the motor out etc.

Cheers!
It's very little effort to get to the assembly. You need to remove the cabin air filter cover which is under the hood, all the way in the back behind the firewall. Comes off with 2 long screws.

Then you need to remove the trim to the left and right of the wiper transmission... not sure what there called but it's the grated bits of plastic that catch all the leaves. They come off with 3 screws each. It's easiest to get to them if you put the all the way up, completely vertical.

The last bit of plastic covering the wiper assembly comes off with no attachments, just a bit of jiggling.

Once i get my new gear in i'll take some pictures of the whole disassembly/assembly process.
 

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94 SL600, 89 Jag XJS conv, 85 Daimler Princess, 97 993 63 Avanti 16 Lincoln MKZ hybrid 16 Silverado
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720 Posts
nice photos. Is this turtle opening for the first generation? ( 89-94) It is the access for my 94.
 

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1990 500SL
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225 Posts
Is those wiper gears somewhere available? In my car wiper hits to right hand side A-pillar, it is very likely that gear is worn out. I try to search on ebay but did not get any hit.
 

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90 300SL
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