71NewYorkMan
Member
Many of you know that the 78 C-body intermittent 2-speed wiper system is a one year only orphan system that requires unobtainable plastic parts to repair. There is a well known and documented fix by @1978 NYB and others that describes how to use 77 and earlier c-body parts as a work around.
1978 NYB wiper woes.
I Am Absolutely Done With 1978 Wiper Cams
Before I bought my 78 NYer, I suspected it would not have a functional wiper system. I read all of the posts I could find on the subject, which alerted me to a "rumor" that b-body parts could also be used as a fix. As I happen to have b-body parts as spares for my Cordoba, I decided to give it it a shot. It works! This particular solution requires no fabrication, but a minor change to the donor b-body linkage will be required.
Some definitions-
"Sweep"- the position of the wiper arm and direction in which the motor turns (counter-clockwise as viewed from linkage end of motor) in normal operation.
"Stop"- the position of the wiper arm in either the intermittent or continuous "sweep" cycle.
"Park"- the position and direction in which the motor turns (clockwise as viewed from linkage end of motor) when system is turned off.
"Stroke"- The motor motion which changes dependent on whether the motor is turning clockwise or anti-clockwise.
"Cam"- Plastic/metallic linkage which changes the length of "stroke" dependent on motor rotation.
"MP"- Murray Park. A well known and respected supplier of used and reproduction Mopar parts.
Some comparison photos for the hardware-
My c-body motor left, NOS b-body motor right. My research indicates several different part numbers for the 78 c-body and 78-79 b-body motors, but they are ALL interchangeable.
Busted c-body link left, busted b-body link right. Notice the 180 degree difference in the indexing of the linkage. This difference is important!
Busted c "cam" shown on parked motor.
Busted b "cam" on parked motor.
Next photo shows c linkage and "cam" on top, b linkage and "cam" bottom. Both of these systems are shown in their approximate "park" positions. Notice the differences in orientation of "cam" and wiper arm mounts.
Next photo shows left to right- original busted 78 b "cam" fully disassembled, busted 1990's replacement Mopar b "cam" partially disassembled, "MP" replacement b plastic "cam" parts, my busted c "cam" assembled.
Now the fix-
I assembled the "MP" plastic parts to the b body metal base. You must reuse the base, spring, c-clip and ball shown in the disassembled original or later service issue b "cam" shown below.
My method of assembling the "MP" parts, original b metal "cam" parts, and original c-body linkage-
Assembled c linkage with reused b "cam" and new "MP" plastic parts-
Next is the ONE modification you MUST make- file the flat in the index hole of the b-body "cam" so that you may position the rebuilt b-body "cam" as similar to the c-body "cam"-
1978 NYB wiper woes.
I Am Absolutely Done With 1978 Wiper Cams
Before I bought my 78 NYer, I suspected it would not have a functional wiper system. I read all of the posts I could find on the subject, which alerted me to a "rumor" that b-body parts could also be used as a fix. As I happen to have b-body parts as spares for my Cordoba, I decided to give it it a shot. It works! This particular solution requires no fabrication, but a minor change to the donor b-body linkage will be required.
Some definitions-
"Sweep"- the position of the wiper arm and direction in which the motor turns (counter-clockwise as viewed from linkage end of motor) in normal operation.
"Stop"- the position of the wiper arm in either the intermittent or continuous "sweep" cycle.
"Park"- the position and direction in which the motor turns (clockwise as viewed from linkage end of motor) when system is turned off.
"Stroke"- The motor motion which changes dependent on whether the motor is turning clockwise or anti-clockwise.
"Cam"- Plastic/metallic linkage which changes the length of "stroke" dependent on motor rotation.
"MP"- Murray Park. A well known and respected supplier of used and reproduction Mopar parts.
Some comparison photos for the hardware-
My c-body motor left, NOS b-body motor right. My research indicates several different part numbers for the 78 c-body and 78-79 b-body motors, but they are ALL interchangeable.
Busted c-body link left, busted b-body link right. Notice the 180 degree difference in the indexing of the linkage. This difference is important!
Busted c "cam" shown on parked motor.
Busted b "cam" on parked motor.
Next photo shows c linkage and "cam" on top, b linkage and "cam" bottom. Both of these systems are shown in their approximate "park" positions. Notice the differences in orientation of "cam" and wiper arm mounts.
Next photo shows left to right- original busted 78 b "cam" fully disassembled, busted 1990's replacement Mopar b "cam" partially disassembled, "MP" replacement b plastic "cam" parts, my busted c "cam" assembled.
Now the fix-
I assembled the "MP" plastic parts to the b body metal base. You must reuse the base, spring, c-clip and ball shown in the disassembled original or later service issue b "cam" shown below.
My method of assembling the "MP" parts, original b metal "cam" parts, and original c-body linkage-
Assembled c linkage with reused b "cam" and new "MP" plastic parts-
Next is the ONE modification you MUST make- file the flat in the index hole of the b-body "cam" so that you may position the rebuilt b-body "cam" as similar to the c-body "cam"-
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