Windshield wiper motor not driving wipers

[my kids took the truck]

I turn on my windshield wipers and they sort of go then stop halfway. I hear something clicking a bit. If I reach out and push on the wiper they will go again but then get stuck again.

It seems like there is some sort of a clutch in the motor and it is slipping. Looking online I did not find much.

Cause: three year old (that is her in my pic) reached out window and grabbed wiper arm and held onto it while wipers running.

Tomorrow I plan to disassemble, clean, and reassemble motor. Just looking for some advice before I go blind.

 

[my kids took the truck]

I removed the cover to the wiper motor. The worm gear and plastic gear look fine. I ran the motor with the cover off and don't see anything. I pushed on the gear with my thumb and it kept going. I had already disconnected the motor and removed it so I did not run it with the wipers connected; will wait a bit and see if anyone has ideas before reconnecting the wiper assembly and retesting.

• Is there any way the wiper assembly in the cowl could be damaged (looks fine but I will cycle it all the way with motor disconnected to make sure it is not binding)?
• Could the electric motor have burned out and now it is weak?

 

[my kids took the truck]

Found it, the plastic gear is turning on the shaft. Not sure how to fix that. It looks like the center gear does not have a shaft key and it is designed to slip if the wipers get jammed on something (frozen to windshield etc.) It looks like after 40 years of K5 life and 20 seconds of my daughter the slip has exceeded the amount allowed before the gear wears out. I checked the wiper assembly and there is no binding. The electric motor turns fine.

It seems like if I could get some friction modifier like belt squeal to wick then that could give enough friction to keep the wipers going. The alternative is a new motor (reman) if I cannot find a replacement gear; so far I have looked online and cannot find that gear.

Look close at this video and notice that when the wipers stop moving the center shaft just sits there while the plastic gear keeps turning.

Found that in my case the cast number is not a part number in the pat book, it is close - in some cases I see the part number is on a sticker stuck to the motor; in this case it is not.

 

[brans87]

Craigslist a parts truck or junkyard. Worse case buy from Rockauto so don't find out you got a bad unit.

 

[diesel4me]

I think the shaft & gear have fine splines on them,and they'll strip fairly easy if the wipers jam on ice ,etc...

Not sure how to fix that--maybe drill a hole in the hub of the gear and put a roll pin in it,it would work best if you could get the drill to drill into the shaft and the gear,a half circle in each part,then the pin would lock them together..it appears there isn't enough of a hub to put in a set screw,if you could drill & tap the gear..

Perhaps some adhesive like super glue or locktite bearing retainer compound might work,but it would suck to have it fail in the middle of a downpour going down the highway..

Those wiper gears are pretty tough despite being nylon--I've seen some guys converted to use as a winch to raise lawn tractor plows and roto-tiller attachments,and everyone on the forums said "yea--that'll work--for about 5 minutes!"..but some are still going strong years later..

What year is your truck ?...I have a wiper motor off a '73 K10 in my shed that was OK when removed,and I doubt it'll fit my 82 or 85 trucks..

 

[my kids took the truck]

I think the shaft & gear have fine splines on them

That sounds correct. Thank you. So I need to find a replacement gear and figure out how to pull the current gear out - it does not just slide out anyways but I did not try prying. They reman these motors so someone must be selling gears.

 

[my kids took the truck]

Worse case buy from Rockauto so don't find out you got a bad unit.

The part numbers given by Rock are a little different http://www.rockauto.com/en/moreinfo.php?pk=32412&cc=1029327&jsn=404
5044764, 5044789, 5044812 versus Delco 4960655
They are $70 more or less
Best deal looks like Amazon w/ free shipping https://www.amazon.com/Cardone-40-160-Remanufactured-Domestic-Wiper/dp/B000C46LRU/ref=au_as_r?_encoding=UTF8&Make=Chevrolet|47&Model=Blazer|420&Year=1974|1974&ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=1&vehicleType=automotive
My local parts sore has them for $55 and in stock http://www.oreillyauto.com/site/c/detail/A1C0/40160/03292.oap?year=1977&make=Chevrolet&model=C10+Pickup+RWD&vi=1030194&ck=Search_03292_1030194_-1&pt=03292&ppt=C0047

I looked around online and the nylon gear is not sold. Found a site where a guy 3D printed himself a new gear. I called A-1 Cardone but they would not tell me where they get their parts (it is proprietary - sure, it is called salvaged from other motors). They did drop that they are reman in Texas.

 

[diesel4me]

Googling that number on your photo shows up as a washer pump assembly..

A-1 Cardone used to be the biggest rebuilder of many parts--lately I've heard their quality ain't so hot--probably farming out their labor to Mexico or hiring unskilled labor perhaps?..

Personally I'd try a boneyard first--wiper motors usually dont fail that often--unless you live in Seattle..prices for used ones are much more reasonable,but I suppose if your truck is in the '74-'77 year range,there may not be many trucks to pick on for parts in salvage yards..I know around here they are getting scarce..

 

[my kids took the truck]

'74-'77 year range,there may not be many trucks to pick on for parts in salvage yards.

I will look online and see where the closest yard is.

Thank you for the heads up on the Cardones. I will think about that.

 

[my kids took the truck]

Times have changed on me - the oldest chevy/gmc truck/blazer/van/suburban the local pick'em has is 1982, and the next oldest is 1985, after that is all '90s; I remember when...

 

[diesel4me]

Dont feel bad--the closest salvage yard to me that had the most square bodies to pick from,had over 100 of them 3 years ago--last year I went there and the yard looked like an empty field,and I counted only 5 square bodies,and most of them were just hulks,no useable engine or drive trains,just gutted out skeletons with junk half cannibalized engines that had been left open to the weather..

Worst part was most of those trucks were not that bad off as far as rust--better than either of mine are!..I saw 2 nice doors rust free,they let someone rip out the "guts" and they chopped a perfect door skin up..and they folded the door panel in half!....nice tires gone to seed from sitting too..cant understand why people junk "good" stuff and the yards end up burying the trucks behind 50 other vehicles,making parts impossible to get at..they cave in any good body panels shoving them around with the forkloader too...
Trying to find a carbed good running V8 around here is getting very tough,and prices are double what they used to get for one..the only ones I see around are a few 305's most of the time..everyone thinks 350's are gold now here..

 

[my kids took the truck]

Dont feel bad--the closest salvage yard to me that had the most square bodies to pick from,had over 100 of them 3 years ago--last year I went there and the yard looked like an empty field,and I counted only 5 square bodies,and most of them were just hulks

It is starting to get like finding flathead parts..

 

[my kids took the truck]

A-1 Cardone used to be the biggest rebuilder of many parts--lately I've heard their quality ain't so hot

I went to the parts store and the cardone has a lifetime warranty. The Cardone tech I called said the wipermotors are rebuilt in Texas. Hopefully I don't have a problem. I asked them to order me a motor, they need to ship it but it should be in this evening.

EDIT: I got the motor - just a heads up, from the parts store the rubber boot is unavailable (I did not see it online either) and the motor seal to firewall is also not available (I did see it for sale online). I will post a few photos but I see now how to disassemble the gear assembly - there is a c-clip on the shaft. If I could have found a motor at the junkyard all I needed was to pop that c-clip and pull the gear - I don't even need a working motor just a clean gear.

 

[my kids took the truck]

Finding the exact wiper motor to firewall seal is more difficult than it should be; O'Reilly never called that they found it. In this thread I posted a photo of the wiper motor.

These are the seals availabe (these links will die but they are good now)

• 3.00" O.D. 70-81 Camaro, 64-65 Chevelle, & 68-77 Chevelle w/ hidden wipers http://www.speedwaymotors.com/Shop/1973-Chevy-Windshield-Wiper-Motor-Seals/37.html
  
• ?" O.D. 67-69 Camaro, 68-69 Chevelle, 68-72 Nova http://www.luttyschevy.com/i-20834727-wiper-motor-to-firewall-seal.html
  
• ?" O.D. 67, 68-69 Camaro http://www.rickscamaros.com/catalogsearch/result/?q=windshield+wiper+seal&x=0&y=0
  
• ?" O.D. 67, 68-69, 70-81 Camaro http://www.camarocentral.com/searchresults.asp?Submit=Go&Search=wiper+motor+seal
  
• found the wiper shaft seals: 59-72 el camino http://www.elcaminostore.com/catalogsearch/result/?q=windshield+wiper+seal

Any clue which it is? I tried looking for the same looking motor and then picking the matching seal

• 70-83 Camero http://www.rickscamaros.com/camaro-...-for-cars-without-delay-wipers-1974-1983.html
  
• 70-76 Camero http://www.camarocentral.com/1970_1976_Windshield_Wiper_Motor_Assembly_p/win-39c.htm
• maybe 68-72 El camino http://www.elcaminostore.com/el-cam...-hidden-wipers-2-speed-acdelco-1968-1972.html

It looks like Camero http://www.speedwaymotors.com/Shop/1973-Chevy-Windshield-Wiper-Motor-Seals/37.html or Camaro http://www.camarocentral.com/searchresults.asp?Submit=Go&Search=wiper+motor+seal should work. But Cardone list for applicable vehicles says only 73-77 C/K/G https://www.cardone.com/Products/Product-Detail?productId=40-160&make=Chevrolet Trucks&model=Blazer&year=1974&info=Front:::

I am double checking parts manual:
73-78 CKG-1, 2, 3, Blazer,Jimmy .............. . 9832955 .60 GASKET, wiper motor (10.152) ....... 23.3862
The part#9832955 found nothing online.

Also, I found the gear (search term "GEAR SHAFT, Windshield Wiper Motor 4960658"). It cost more than the rebuilt motor including core charge http://www.oldsobsolete.com/product...hield-wiper-motor-gear-and-shaft-nos-4960658/ Here it is $14, when will I learn to lookup part numbers and use them for search terms http://www.ebay.com/itm/1973-1977-C...ash=item4d4203f216:g:lvAAAOSw6wRW~xon&vxp=mtr

Conclusion: I will try the speedway motors gasket and see - if for no other reason than they are the only one that posted the O.D. and 3" is about right.

 

[my kids took the truck]

Final post - the motor is on and works good. I used the A-1 Cardone remanufactured part. These photos are of the gasket that goes between the motor and firewall. It fits perfect. This gasket was not that easy to find. Sometime in the future I will disassemble the gear on the old motor and take a look at what was going on with the gear shaft splines.





Add to that list '74 K5