78 wiper linkage - I've joined the club

HombreCalgarian

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Hello all,
Have not posted anything here for quite some time - there was not much to report, really. We just drove around without any issues. Did a winter run in December in between big snowstorms before Xmas. Chinook cleaned and dried the roads. So it was still a bit nippy, but dry.
uZvlILx6qifaIfiY212qDuZOVj-UdMMvsMb3Vb3WXqvx5TXMY9i0wvzRJyBo0IyzvnKctt=w1371-h1028-no?authuser=0.jpg


Old Mopars can do ice-skating
iSNYZ9gOZFh2G8rHRxTh_IQY9RyK1pZd6sES-oKobOUZrS0mpNlS6sEKfUSawtqhVJfp3E=w1371-h1028-no?authuser=0.jpg


A couple weeks ago Wife took the car a wee bit above 150 km/h indicated (about 95 mph in imperial money). Reported later the car was smooth as butter and very stable.

Yesterday I took the car to a car wash to remove the bug cemetery from the front. During the final wipe-off the wipers stopped midway, accompanied by a clunk from where the linkage is.
JuGceBqMf30MqnJqok6VUiZ99hII27yVlZnXOsnR9nkCLvBqJPsLxHzQo83Pidz8QL6iz6G=w1600-h901-no?authuser=0.jpg

Further inspection at home revealed this. The left arm just fell off the motor, hence the clunk.
T5fU7iqjNVRkApcfZVQz5DmK2CdDU95dYivh8IupzT_x0qvf91LjZg7ubeLmLZC2NH6dS4h=w771-h1028-no?authuser=0.jpg


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So I assume the 78 big cam disease struck me too.
As a permanent fix willing to go the 74-77 mod route.
Can some(C)body help out with the 74-77 donor parts? Actual parts, or pointers where to buy/source?
dsc02240-jpg.jpg


And finally - is there a way of putting the engine hood in a service position of a sort, old Mercedes-like? Like pulling both 'legs' forward past the notches and raising the hood at the same time?

Thanks a lot for all tips and answers.
 

Mr C

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There is no fancy hood configurations...don't mess with it...it weighs a ton. Don't want you getting hurt.

I see you know the solution. Works great.
 

1978 NYB

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Like Mr. C. said.....the hood weighs a ton. Saying that, it was easier for me to work on the wiper linkage with the hood off. I had 2 other people holding the hood while I unbolted it. Make sure you mark the hood around both hinges before you remove the hood (if you go that direction) so the hood lines up and your gaps stay the same when you put the hood back on.
 

1978 NYB

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As far as donor parts.....

Murray Park at

www.cbodies.com

Is probably your best bet for donor parts. Email him and he'll get back to you. It's only him and his wife working the yard so don't expect an instant response. It might take several days. Murray also tried to repop the 1978 wiper cam. The one he manufactured is for a 1979 R body. It won't work for a 1978 C body but I'm told if change all the parts to a 1979 R body the orange wiper cam he made will work.

More donor parts at www.wecrash.com. The derby guys don't need wipers.
 

HombreCalgarian

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As far as donor parts.....
Murray Park at
www.cbodies.com
Is probably your best bet for donor parts. Email him and he'll get back to you.
More donor parts at www.wecrash.com. The derby guys don't need wipers.

Thank you for the tip. Since I am searching everywhere, can you please detail what exactly will I need from the older C-Bodies? Also, mine is intermittent type, will there be any difference with the donor?
Thanks!
 

traintech55

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Glad you stated that you have "Intermittent Wipe" That system uses the two speed motor, and the "Cam" In the linkage to park the wipers off the glass. Another way you could go is to change to the Three speed wiper system, Different motor and wiper linkage. The wiring from inside the car is the same, different switch also. The three speed motor has the "Park" built into the motor so you don't have to worry about it breaking again.
 

1978 NYB

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You need the offset piece that mounts to the wiper motor and the linkage rod that goes from the left wiper transmission to the wiper motor.
You can get the small cam which is the same bushing for all of the wiper linkage bushings from a Dodge dealer. They were $9 something a piece. I negotiated with my local dealer for $5.50 a few years ago. You will want to use the factory cam/bushings and not the junk that comes in a Help various bushing package.

87F7070E-0A28-4591-A1F7-E51C69D56B20 (1).jpeg
 
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1978 NYB

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Glad you stated that you have "Intermittent Wipe" That system uses the two speed motor, and the "Cam" In the linkage to park the wipers off the glass. Another way you could go is to change to the Three speed wiper system, Different motor and wiper linkage. The wiring from inside the car is the same, different switch also. The three speed motor has the "Park" built into the motor so you don't have to worry about it breaking again.

My mod fix is for the intermittent wiper system.
 
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Sport Fury 67

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The transmission arm from the windshield wiper motor pivot flange/cam to the first pivot on the driver’s side needs to be sourced from an earlier C-Body. I obtained mine from a junk yard from a 1974 New Yorker. Any C-body will work.

The transmission arm from my 1978 NY is the top one in the photo – p/n 341759 58622.

The transmission arm from the 1974 is P/N 341754 58622 – the bottom one in photo.
I had a welder cut the end off that mated with the bad plastic cam fitting for my 78. I had a welded cut the end from the 1974 and weld it onto the 78 arm. I recall the welder telling me the overall length was 19 inches?

Transmission arms 3  .jpg
 

Sport Fury 67

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Next you have to modify the pivot cam that mates to the WW motor shaft.

The pivot cam from the 1974 is P/N 343752 58622 –top left in photo.

The pivot cam from the 1978 is P/N 3799437 58622 – bottom left and right photo.

Flange 1 .jpg


Flange Bottom .jpg
 

Sport Fury 67

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There is a height difference between the 78 and the 74 cam pivots. If you measure, the offset -height for the 74 is 1.5 cm. The height offset for the 78 is higher, about 2.2 cm. Using a Dremel and a bench grinder, I cut and reduced the overall height of the 78 pivot point until overall height will accommodate the flange thickness and total pivot height of the 74 cam.

cut off .jpg


74 pivot .jpg


Finished end .jpg
 

Sport Fury 67

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The weld shop I went to charged me $75 to weld the two parts for me. I protected both pieces with a shot of black Rustoleum paint.

Like Bob said, replaced the three polymeric – plastic bushings with new ones I bought at a dodge dealer for $7 each. Don’t go cheap and get the Dorman knock offs, you will see the difference . P/N 0379 9089 -009
 

HombreCalgarian

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The weld shop I went to charged me $75 to weld the two parts for me. I protected both pieces with a shot of black Rustoleum paint.

Like Bob said, replaced the three polymeric – plastic bushings with new ones I bought at a dodge dealer for $7 each. Don’t go cheap and get the Dorman knock offs, you will see the difference . P/N 0379 9089 -009

So many thanks for the detailed report. Now it only depends how soon I find the donor parts... AB Canada in this regard seems like living on a Moon...
 

HombreCalgarian

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My take at solving the dreaded 78 linkage insert problem. Should admit it is not for everybody.
Pros - does not need donor parts.
Cons - Requires time, patience and lots of tools.

My solution was driven by time constraints (driving season is here and it is short), no access to 73-77 donors (methinks this retrofit would have been the easiest and the most elegant solution from engineering standpoint) and no immediate access to a welder. But I had access to a lathe, my own drill press and a dremel with multiple attachments.
As for the material for a new bushing, after some research and consultations I bought a foot-long 1.5" OD acetal bar for less than 20 bucks.
Why acetal? It is tough, easily machined to a great precision, is self-greasing, resists wear, and is hydrofobic.
From a website: Due to its low moisture absorption rate, Acetal’s physical properties remain constant in every environment, resulting in an ideally suited and stable product for close tolerance mechanical parts and electrical insulators. Acetal is designed to resist damage from most chemicals and solvents. In high moisture or submerged applications, Acetal bearings outperform nylon 4-to-1.
Next best - UHMW, third best - extruded nylon.

I dusted off my draughtsman skills (I am an old-school paper/pencil type, can't do it in AutoCAD) and after some caliper-twisting cobbled up a drawing for the machinist. Machining the external shape did not take much time. But the rest took much time to plot, mark, carve, drill and tap - especially since the friendly machinist is 1,5 hours away and I only had 1 linkage to play with - I did not want to err on anything.
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First test-fit:
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I figured that no matter how I try to replicate the snap-on lock of the original part, with available tools and skill level it will not be a reliable solution. So to maintain the bushing seating on the motor shaft I drilled the shaft and tapped it to accept an M4 hex head bolt.
hFnRLDRdETRrS5qw671ENHkyAcKfO4-fWBuLm8XGOpWlolq_thOAWqmHA-Z7ZkrxhNP8EZ=w1520-h1086-no?authuser=0.jpg

Note to anybody who decides to go the same route - the shaft is hardened on the surface to a point when any drill bit will not leave a trace on it no matter how you try. I managed to carve through this shell only with a carbide dremel burr. But then to finish the hole you still need the best available "cobalt" bits. I went through at least 4 milwaukees before I was done.
And go extremely easy with the taper tap. Lots of oil, one cutting revolution at a time, then back off, clean, oil, repeat. You do not want the tap to snap in there.

Since the bolt has to move in relation to the bushing, I put an extra nylon washer between the bushing and the steel washer.
So far it runs well.
 

Jeff Henry

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I dusted off my draughtsman skills (I am an old-school paper/pencil type, can't do it in AutoCAD) and after some caliper-twisting cobbled up a drawing for the machinist. Machining the external shape did not take much time. But the rest took much time to plot, mark, carve, drill and tap - especially since the friendly machinist is 1,5 hours away and I only had 1 linkage to play with - I did not want to err on anything.

Hey Hombre,
I know AutoCad. Would you consider sharing your drawing and I will turn it into a 3d drawing and post it here. I also have a 3D printer here in Kansas City that will make them for me. Not sure on the material, but they assured me it was tough enough for car parts. I will find out more details and post them here.
 

1978 NYB

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My take at solving the dreaded 78 linkage insert problem. Should admit it is not for everybody.
Pros - does not need donor parts.
Cons - Requires time, patience and lots of tools.



My solution was driven by time constraints (driving season is here and it is short), no access to 73-77 donors (methinks this retrofit would have been the easiest and the most elegant solution from engineering standpoint) and no immediate access to a welder. But I had access to a lathe, my own drill press and a dremel with multiple attachments.
As for the material for a new bushing, after some research and consultations I bought a foot-long 1.5" OD acetal bar for less than 20 bucks.
Why acetal? It is tough, easily machined to a great precision, is self-greasing, resists wear, and is hydrofobic.
From a website: Due to its low moisture absorption rate, Acetal’s physical properties remain constant in every environment, resulting in an ideally suited and stable product for close tolerance mechanical parts and electrical insulators. Acetal is designed to resist damage from most chemicals and solvents. In high moisture or submerged applications, Acetal bearings outperform nylon 4-to-1.
Next best - UHMW, third best - extruded nylon.

I dusted off my draughtsman skills (I am an old-school paper/pencil type, can't do it in AutoCAD) and after some caliper-twisting cobbled up a drawing for the machinist. Machining the external shape did not take much time. But the rest took much time to plot, mark, carve, drill and tap - especially since the friendly machinist is 1,5 hours away and I only had 1 linkage to play with - I did not want to err on anything.
View attachment 464771

View attachment 464772


View attachment 464773

First test-fit:
View attachment 464774
I figured that no matter how I try to replicate the snap-on lock of the original part, with available tools and skill level it will not be a reliable solution. So to maintain the bushing seating on the motor shaft I drilled the shaft and tapped it to accept an M4 hex head bolt.
View attachment 464775
Note to anybody who decides to go the same route - the shaft is hardened on the surface to a point when any drill bit will not leave a trace on it no matter how you try. I managed to carve through this shell only with a carbide dremel burr. But then to finish the hole you still need the best available "cobalt" bits. I went through at least 4 milwaukees before I was done.
And go extremely easy with the taper tap. Lots of oil, one cutting revolution at a time, then back off, clean, oil, repeat. You do not want the tap to snap in there.

Since the bolt has to move in relation to the bushing, I put an extra nylon washer between the bushing and the steel washer.
So far it runs well.

Very nice work!
 

3175375

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Hey Hombre,
I know AutoCad. Would you consider sharing your drawing and I will turn it into a 3d drawing and post it here. I also have a 3D printer here in Kansas City that will make them for me. Not sure on the material, but they assured me it was tough enough for car parts. I will find out more details and post them here.
Please do

I am considering having a clip made for a non-Mopar vehicle that is discontinued using delrin and mill, or 3D printing the part using something similar to nylon…
 
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