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snoopy2x

Rebuilding American Bosch WWF Windshield Wiper Motors

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The American Bosch WWF electric wiper motors first appeared on the Kaiser Jeep CJs during the mid-1960's (I believe sometime in '66), replacing the previous vacuum-operated wiper system. My 1967 CJ5 has the original WWF motors, which were still working except for the "parking" of the wiper blades that's supposed to occur when the switch is turned off. I know the jeep's original owner, and he did not recall the wiper motors ever having been serviced during their 50 year lifespan - so it seemed like a full rebuild might be a good idea.

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Instructions for installing and adjusting the WWF motors published by American Bosch in 1968:

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The factory-installed electric wiper motors on my '67 CJ5 are single-speed. The original one-speed wiper switch is a rather unusual four-terminal configuration. There are two separate "hot" red power wires leading from the switch to each of the two motors, as well as a constantly powered brown "park" wire, and the fourth bluish-white wire is the 12v input from the ignition switch. Some photos of the original switch are below (the first two were taken when I removed the switch, and the last two after it was cleaned):

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The wiring harness for my jeep, which was recently replaced, was built by Carl Walck at Walck's 4WD, who did a fantastic job with it. The one part of the harness that was non-standard, and was therefore not included with the main harness, was the windshield wiper wiring, which is a completely separate (and vehicle-specific) harness. I sent the old wiper harness, which was in pretty bad shape, to Carl and asked him to use it as a pattern to build a new one for me to the original specs, which he did. It turned out that was the first time he'd had a pattern in hand to build one from.

The only somewhat difficult part of removing and disassembling the motors was taking the wiper arms off of the splined heads on the wiper motor shafts. The problem is that there are very small metal clips in the ends of the wiper arms that have to be released in order to pull them off of the splines, but there is no angle from which these clips can be viewed when the wiper arms are installed - so I was working blind. After spraying a little PB Blaster into the splines to loosen them up some, I finally succeeded in removing them by using a small mirror and a hooked metal probe to press back the metal clips and slide the arms off of the splined heads.

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After unscrewing the 3/4" nut from the front of the threaded wiper shaft sleeve and unbolting the spacer at the other end of the motors, they could be pulled through the windshield and disconnected from the harness.  
 
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There are four small screws that allow removal of the gearbox plate.  I was pleased to find that even after 50 years of use, the gearboxes in both of the motors are in remarkably good shape.  Note the circular brass "button" contact over the spring, which activates the motor's parking function.
 
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The parking circuit of these motors is an interesting design.   Here's a link to an excellent post by Jon McKenzie on the Early CJ5 website, including photos, that shows how the wiring and the parking circuit work when operating as they're designed to:  
 
 
Though the gearboxes themselves were surprisingly clean when I disassembled them, the semicircular shaped electrical "bridges" that operate the motors' parking function were very dirty on on both motors, which is likely what caused them to stop parking at some point.
 
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A small spring clip on the "crank" at the end of the wiper shaft retains the internal working parts.  Once this is removed, the remaining internal parts can all be lifted out from the gearbox.  Only the wiper shaft, which is swaged to the crank bracket on the housing end, and to the splined head on the other, is not removable from the housing.
 
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The wiper gearboxes were factory set for a 120-degree sweep:
 
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After removing the two long machine screws that hold the parts of the motor together and attach it to the gearbox, disassembly of the motors was complete.   The brushes and armatures of both motors are fortunately still in excellent shape, as are the bronze bushings, as there was no discernable runout / lateral end movement in either of the motor shafts.
 
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Some slight water intrusion had clearly occurred in the drivers side motor at some point, and I used a Dremel with a small circular wire brush to remove the rust inside the cylindrical motor casing and on the two ends.  Note:  If you have to do this, I would strongly suggest using a brass brush, rather than a steel one, on the Dremel.  I learned the hard way that if a steel brush is used, the magnets inside the motor will collect ALL of the tiny wires that come off of the brush during use  (and removing those wasn't fun!)
 
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With the rust removed, and all parts thoroughly de-greased and cleaned with denatured alcohol, the motors are now ready for relubrication and re-assembly.  
 
I've been reading up a lot on greases -  a subject about which I've always had a significant knowledge deficit - and have learned quite a bit.   Among other things, what I've read is most often recommended for use in electric motors is polyurea-base grease of NGLI #2 consistency.  Apparently this particular type of grease is extremely stable in terms of its viscosity over a wide temperature range, so it provides good bearing lubrication upon motor startup even in very cold or very hot conditions.   
 
Here's a grease of this type designed specifically for electric motor ball bearings:   https://smile.amazon.com/gp/product/B017WKDTSA/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1   However, these particular motors have bronze bushings, not ball bearings, so I asked Moses about this offline.  He felt this would be a good grease to use for this application as well, so I picked up a tube.  
 
Moses also recommended a particular Bosch Tool Gear Grease for the gearboxes , so I got a tube of that as well: https://smile.amazon.com/BOSCH-POWER-TOOLS-Replacement-Part-1615430005-Grease/dp/B002ENJ9OO/ref=sr_1_1?ie=UTF8&qid=1485183768&sr=8-1&keywords=bosch+tool+grease
 
The problem of lubricating the rotating wiper shafts, as both of its end fittings are swaged and not meant to be disassembled, was solved by creating a simple "adapter" from a short piece of 5/8" ID x 7/8" OD tubing.  This adapter allowed the connection of a grease gun to the end of the wiper shaft, and force (chassis) grease between the wiper shaft and the threaded sleeve.  The tube was tightly hose-clamped to the end of the grease gun, using electrical tape to help make a grease-tight seal, and the other end placed over the spline end of the wiper shaft assembly and hose-clamped about halfway down the threaded brass sleeve (shown here without the hose clamps):  
 
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The amount of clearance between the shaft and sleeve is fairly tight - there is maybe 1mm of longitudinal shaft end play.  It took a good deal of pressure and some time for the grease to make its way down through the tiny opening and start to ooze out of the other end of the sleeve / shaft assembly mounted in the housing.  Working the small crank bracket on the wiper shaft back and forth to help distribute the grease evenly inside while pumping the gun's handle, the grease eventually made it all the way through (though I had to stop applying pressure when the tube expanded so much that I was afraid it might actually burst):   
 
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After unscrewing the 3/4" nut from the front of the threaded wiper shaft sleeve and unbolting the spacer at the other end of the motors, they could be pulled through the windshield and disconnected from the harness.

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There are four small screws that allow removal of the gearbox plate. I was pleased to find that even after 50 years of use, the gearboxes in both of the motors are in remarkably good shape. Note the circular brass "button" contact over the spring, which activates the motor's parking function.

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The parking circuit of these motors is an interesting design. Here's a link to an excellent post on this forum by jwmckenzie (Jon McKenzie) including photos that show the original wiring arrangement and how the parking circuits work when operating as they're designed to:

Wiper motor question?

Though the gearboxes themselves were surprisingly clean when I disassembled them, the semicircular shaped electrical "bridges" that operate the motors' parking function were very dirty on on both motors, which is likely what caused them to stop parking at some point.

[IMG]

A small spring clip on the "crank" at the end of the wiper shaft retains the internal working parts. Once this is removed, the remaining internal parts can all be lifted out from the gearbox. Only the wiper shaft, which is swaged to the crank bracket on the housing end, and to the splined head on the other, is not removable from the housing.

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The wiper gearboxes were factory set for a 120-degree sweep:

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After removing the two long machine screws that hold the parts of the motor together and attach it to the gearbox, disassembly of the motors was complete. The brushes and armatures of both motors are fortunately still in excellent shape, as are the bronze bushings, as there was no discernable runout / lateral end movement in either of the motor shafts.

[IMG]

Some slight water intrusion had clearly occurred in the drivers side motor at some point, and I used a Dremel with a small circular wire brush to remove the rust inside the cylindrical motor casing and on the two ends. Note: If you have to do this, I would strongly suggest using a brass brush, rather than a steel one, on the Dremel. I learned the hard way that if a steel brush is used, the magnets inside the motor will collect ALL of the tiny wires that come off of the brush during use (and removing those wasn't fun!)

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With the rust removed, and all parts thoroughly de-greased and cleaned with denatured alcohol, the motors are now ready for relubrication and re-assembly.

I've been reading up a lot on greases - a subject about which I've always had a significant knowledge deficit - and have learned quite a bit. Among other things, what I've read is most often recommended for use in electric motors is polyurea-base grease of NGLI #2 consistency. Apparently this particular type of grease is extremely stable in terms of its viscosity over a wide temperature range, so it provides good bearing lubrication upon motor startup even in very cold or very hot conditions.

I came across a grease of this type online designed specifically for electric motor ball bearings: Amazon.com: Mobil Polyrex EM Electric Motor Bearing Grease, Blue, 13.7 oz. Tube: Automotive However, these particular motors have bronze bushings, not ball bearings, so I asked Moses Ludel at the 4WD Mechanix site about this. He felt this would be a good grease to use for this application as well, so I picked up a tube. Moses also recommended a particular Bosch Tool Gear Grease for the gearboxes , so I got a tube of that as well: Amazon.com: BOSCH POWER TOOLS Replacement Part 1615430005 Grease: Home Improvement

The problem of lubricating the rotating wiper shafts, as both of its end fittings are swaged and not meant to be disassembled, was solved by creating a simple "adapter" from a short piece of 5/8" ID x 7/8" OD tubing. This adapter allowed the connection of a grease gun to the end of the wiper shaft, and force (chassis) grease between the wiper shaft and the threaded sleeve. The tube was tightly hose-clamped to the end of the grease gun, using electrical tape to help make a grease-tight seal, and the other end placed over the spline end of the wiper shaft assembly and hose-clamped about halfway down the threaded brass sleeve (shown here without the hose clamps):

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The amount of clearance between the shaft and sleeve is fairly tight - there is maybe 1mm of longitudinal shaft end play. It took a good deal of pressure and some time for the grease to make its way down through the tiny opening and start to ooze out of the other end of the sleeve / shaft assembly mounted in the housing. Working the small crank bracket on the wiper shaft back and forth to help distribute the grease evenly inside while pumping the gun's handle, the grease eventually made it all the way through (though I had to stop applying pressure when the tube expanded so much that I was afraid it might actually burst):

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As a sealant for reassembly, I ordered a tube of Loctite Superflex sealant  (https://www.amazon.com/SEPTLS44259330-Superflex-Silicone-Adhesive-Sealants/dp/B001VXWCTM), which Moses mentioned that he has successfully used in some recent axle builds.  He described it as a sealant that remains pliant, and may seal better than the more common RTVs for this type of application.  Be aware however that it “cannot be painted” when detailing.

 
This is where I am with the rebuild at present, waiting for the Loctite Superflex to arrive.  
 
I'm wondering if I should seal not only the gearbox lid with the Loctite, but also the motor housings - though I can see no evidence that these were sealed originally.  Would there be any problem with using the Loctite to also seal the joints around the ends of the motors, or would they be better off left unsealed as originally manufactured?  

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This topic post is a real service for vintage Jeep CJ owners, snoopy2x!  Your attention to detail and clear photos will be very helpful...

As for sealing areas that were not originally sealed, there are arguments for and against...If you're confident these motors are in their original factory state, and if no sealant was applied, it's possible that Bosch wanted these motors to "drain" in the event of exposure to rain or elements.  Another reason for not fully sealing the motor housings could be pressure within the wiper motor case: Pressure created by moving parts could drive out grease, and Bosch may have wanted that kind of pressure to escape from the motor housing.  

Or it could just be that these were universal application motors with the majority of applications having a cab.  A cab would mean no exposure to water and therefore no need for sealing.  

In the Jeep CJ application, the wiper units would be more exposed to the elements.  Jeep CJ Universal 4x4 models were intended for use with or without a top in place.  They were often exposed to the elements and doused with a water hose, pressure sprayer or by thundershowers.  (On models with a heater/defroster option or aftermarket installation, the defroster ducts take real abuse here; keep water away from the dash defroster ducts!)

 Use your judgment here.  I doubt there's an official answer available today.

Moses

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After successfully lub'ing the wiper shafts, I moved on to reassembling the motors. The first step was to apply the Mobil electric motor bearing grease on the original bronze bushings:

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The motor housing parts are all "keyed" where they fit into one another, which is helpful in putting them back together correctly. Given that there was some rust inside one of the motors where it had leaked sometime during the past 50 years, I decided to go ahead and seal the casings parts during reassembly. Once I'd confirmed how the parts fit together, I used the Loctite Superflex sealant to create a watertight seal between them.

One useful trick in reassembling these WWF motors is to temporarily hook the brush wires back behind the small metal brush housings in order to allow placement of the motor shaft correctly within the front portion of the housing. The Loctite was applied to the front end of the motor housing at this point as well:

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Once the shaft is inserted to the point shown in the photo below, the brush wires were "unhooked" to allow the brushes to contact the commutators properly.

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After fully reassembling the motors themselves, the next step was to reassemble the gearboxes. I cleaned any visible grease off of the ends of the motor and wiper shafts, then reassembled the gearboxes using the Bosch tool grease. The cleaned parking circuit connectors (both the semicircular piece attached to the lid, and the copper alloy connector "button" over the small coil spring) were coated with Deoxit Shield. Note that the pin in the arm connecting the gear to the wiper shaft is placed in the 120-degree hole, as originally configured.

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On one of the motors, the insulation on the small wires connecting the parking circuit to the power supply showed signs of blackening / slight burning. It's possible that the insulation been worn through from vibration over time, and the wires had shorted at some point. Using an ohmmeter, I was able to confirm that the wires themselves still tested okay in terms of resistance, so I used shrink wrap to re-insulate them before putting everything back together:

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After running a thin bead of the Loctite Superflex around the edges of the gearbox lids and reinstalling them, the motors were ready for testing. I'm happy to say that both perform properly and run very quietly. The excess Loctite was cleaned from the housings, and the motors were repainted using using VHT epoxy black gloss spray paint.

The motors were then reinstalled on the windshield frame and connected to the new wiper wiring harness from Walcks. Note that the original factory setup used an unfused 12v power wire from the ACC side of the ignition switch to the wiper switch. I opted to replace this original wire with a new one I made with a 10-amp inline fuse added into it.

The newly rebuilt motors mounted on the windshield frame:

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Beautiful work, snoopy2x!  You've done everyone in the vintage Jeep community a big favor with the thorough research and documentation of this rebuild.  So many of these Bosch motors can benefit from this topic and your highly graphic posts.  Thanks much for sharing...

The current replacement motors are off-shore, cheaply designed and built, nowhere near the quality of these Bosch types.  You have restored your CJ-5 to OE standards and then some.  I would expect these motors to run flawlessly for a very long time!

Moses

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Thanks for the kind words, Moses!  

One thing I forgot to mention, for the benefit of anyone else who decides to replace their wiper wiring harness, is that I was able to locate an excellent replacement for the plastic wiring clamps used to attach the harness to the inside of the windshield frame.  Visually, they're almost a dead match for the original plastic clamps used by Kaiser Jeep in the late 1960s, but these are made of nylon rather than plastic.  

The replacements are Ancor 402312 Marine Grade Black Nylon Cable Clamps (5/16" dia.).   I found them on eBay, but I'm sure they're available from a number of different sources.   Here's a photo showing one of the surviving original plastic clamps from my 1967 CJ5 on the left next to one of the new Ancor clamps on the right:  

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A total of 8 of these clamps were required on my jeep.  I used #10 x 1/2" stainless steel Phillips panhead sheet metal screws, which are very close in appearance to the original screws, to attach the clamps to the windshield frame. 

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