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ALIKA T3
Samba Member
Joined: July 30, 2009
Posts: 7229
Location: Honolulu,Hawaii and France
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 Posted: Wed Aug 06, 2025 2:13 am Post subject: Front wiper motor, different models? 251955113C |
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Hello!
I have a stupid question, because it seems to me the later wiper motors on Vanagon work faster than the early models, especially in high speed, yet the part number is the same on all of the ones I come across, from 1984 up to 1991, donor vans all have 251955113C motors...
I know the position of the driver side shaft got modified, so maybe the linkage is more efficient this way? EDIT: I said something stupid, it's the position of the wiper nozzle squirter that has changed, the linkage is unchanged.
I don't think the painted parts vs galvanized depending on the years change the speed 
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Last edited by ALIKA T3 on Sun Aug 17, 2025 7:12 pm; edited 1 time in total |
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Nitramrebrab72
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Joined: November 10, 2018
Posts: 911
Location: France
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| Posted: Wed Aug 06, 2025 2:18 am Post subject: Re: Front wiper motor, different models? 251955113C |
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| Different leverage lengths on the linkages could of made for faster blades. |
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raygreenwood
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Joined: November 24, 2008
Posts: 23232
Location: Oklahoma City
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| Posted: Wed Aug 06, 2025 7:44 am Post subject: Re: Front wiper motor, different models? 251955113C |
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| ALIKA T3 wrote: |
Hello!
I have a stupid question, because it seems to me the later wiper motors on Vanagon work faster than the early models, especially in high speed, yet the part number is the same on all of the ones I come across, from 1984 up to 1991, donor vans all have 251955113C motors...
I know the position of the driver side shaft got modified, so maybe the linkage is more efficient this way?
I don't think the painted parts vs galvanized depending on the years change the speed |
Typically the difference is gear ratio inside. If the factory wanted to upgrade how well a part like this works....without making a complete new assembly.....with a new part #....they keep the housing, the motor and everything else the same. They mold a new larger diameter worm gear for the shaft and a smaller diameter spur gear for the output shaft.
The problem is that without getting into really deep bevels or long gear teeth, they can only change this ratio by so much before they have to physically move the motor shaft closer or farther from the spur gear. That, and if the rotating diameter changes too much it does not fit the linkage ratio and it may shorten the wiper stroke.
But, just a few teeth can make a sizable speed difference.
I found this out on my 412 which has a noticeably slow wiper system. The first things I did was make sure it had clean dedicated power, and ran an extra ground wire (which some cars already had) to a male tab under one of the screws on the gearbox plate. This actually made some difference....I think my stopwatch work back in those days said ~5%.
Then I cleaned out the tacky grease from inside and ran superlube grease thinned with superlube gear oil. I put a thin smear of RTV around the edge of the lid. Let it dry to form a thin gasket, filled the box and screwed on the lid. No leaks.
That made about another 10% difference....big time.
Then I started looking at wiper motors from other cars in the junkyard that had a close enough form factor....and...that I already Knew had faster wipers. I was looking at old Volvos and Rabbit/jetta mk1 and mk2.....80s cars. I snagged a mk1 wiper motor at pick and pull for $5.
Noticably faster ....quite good enough......when I tested it. When I opened it up on the bench, that's when I saw the smaller spur and larger worm and the lightbulb went on in my head of why later motors are faster.
I have not installed it yet. When I get to that stage I will post a write up.
Ray |
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raygreenwood
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Joined: November 24, 2008
Posts: 23232
Location: Oklahoma City
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| Posted: Wed Aug 06, 2025 10:14 am Post subject: Re: Front wiper motor, different models? 251955113C |
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I just realized that the motor you are speaking of ...IS...teh same motor from a mk 1 rabbit that I have
251955113C as you note.
The only thing I can think of on later models that may make them faster is either a gear ratio change as I noted...or much smoother linkage and spindles.
That is another thing that goes a LONG way toward a faster wipe rate 9along with clean power and grounds)...is to remove and polish the wiper spindle shafts, put very low tack grease in (John deere corn head or any NLGI 00 like superlube)...same on the ball joints.
Ray |
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ALIKA T3
Samba Member
Joined: July 30, 2009
Posts: 7229
Location: Honolulu,Hawaii and France
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| Posted: Sat Aug 09, 2025 7:58 pm Post subject: Re: Front wiper motor, different models? 251955113C |
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Thank you both for your input. It can't be a polishing or lubricating issue, virtually every newer van, even rusty POS go faster than mine, that was a time capsule van with mint wiring.
I'll try open a newer one see if there's anything I missed between the 2 models, I didn't tinker with it yet.
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 23232
Location: Oklahoma City
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| Posted: Sat Aug 09, 2025 9:32 pm Post subject: Re: Front wiper motor, different models? 251955113C |
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| ALIKA T3 wrote: |
Thank you both for your input. It can't be a polishing or lubricating issue, virtually every newer van, even rusty POS go faster than mine, that was a time capsule van with mint wiring.
I'll try open a newer one see if there's anything I missed between the 2 models, I didn't tinker with it yet. |
The other things that REALLY help as I noted are lighter/lower drag lubricant...and....this may be the difference from model to model...check how the power is fed to it. What else is on that circuit. Wiper motors are very voltage sensitive. Measure the voltage at the unit when it runs. Ray |
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ALIKA T3
Samba Member
Joined: July 30, 2009
Posts: 7229
Location: Honolulu,Hawaii and France
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| Posted: Sat Aug 09, 2025 10:46 pm Post subject: Re: Front wiper motor, different models? 251955113C |
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| raygreenwood wrote: |
| ALIKA T3 wrote: |
Thank you both for your input. It can't be a polishing or lubricating issue, virtually every newer van, even rusty POS go faster than mine, that was a time capsule van with mint wiring.
I'll try open a newer one see if there's anything I missed between the 2 models, I didn't tinker with it yet. |
The other things that REALLY help as I noted are lighter/lower drag lubricant...and....this may be the difference from model to model...check how the power is fed to it. What else is on that circuit. Wiper motors are very voltage sensitive. Measure the voltage at the unit when it runs. Ray |
The thing is earlier vans had a different fuse panel, but the wires are the same.
I'm actually repairing some fire damage and stole the loom for the wiper motor from a late van, I'll just change the E1 connector for the earlier spade style.
I have a ground tree behind the glove box for some accessories, I might tie in the ground there to help, but first is to look at both motors see if I spot a difference. Funny thing is it has a C suffix, so it changed already from the earlier versions, prolly very early.
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Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget |
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ALIKA T3
Samba Member
Joined: July 30, 2009
Posts: 7229
Location: Honolulu,Hawaii and France
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| Posted: Sun Aug 17, 2025 7:14 pm Post subject: Re: Front wiper motor, different models? 251955113C |
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I will post pictures when I have time, but I found there's some kind of capacitor on the grey/black wire pin outside of the motor on later motors. That might be the explanation.
I also edited my first message:
| Quote: |
| EDIT: I said something stupid, it's the position of the wiper nozzle squirter that has changed, the linkage is unchanged. |
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget |
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ALIKA T3
Samba Member
Joined: July 30, 2009
Posts: 7229
Location: Honolulu,Hawaii and France
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| Posted: Wed Aug 20, 2025 12:30 am Post subject: Re: Front wiper motor, different models? 251955113C |
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1988, 1988 with the blue tape and I also had written it down, 1986, 1984 in black and lone motor 1984 as well. Dates cast on the motors.
Notice how the U shaped linkage bars are fit either way.
They went from black paint to galvanized prolly in 86.
The numbers stamped are the distance center to center in millimeters.
Early motors don't have this resistor, or whatever it is. On the grey/black wire pin
Late
Early
VW Jetta 1983 motor vs Vanagon motor just for kicks. Very similar
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Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget |
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