Replacing windshield wiper motor

[IDAHO 71]

The cowl panel has been removed, along with the plastic screening beneath that.
The only way to see what the wiper motor connects to is a very slanted view. There is no large opening like on later trucks.
A nut can be seen that attaches the motor to the transmission for the wipers. Is that the only nut that has to come off to replace the motor, or are there more connections to the wiper arm transmission/

Also, any tips on lubricating the wiper arm transmissions would be appreciated.

[Your41Plague12]

Loosen (DO NOT FULLY REMOVE) the two nuts that connect the transmission on the motor assembly to the linkage rod going to the wipers. It will be a clamp setup that tightens down on a ball at the end of the transmission arm. If you take the nuts off all the way, they're really difficult to keep your fingers on, and will most likely get lost in the firewall. If you're having trouble seeing or getting access to the clamp inside the firewall/cowl, simply remove the three mounting bolts on the firewall that go through the rubber bushings, disconnect the three (or two, on the later models) wiring harnesses, and move the wipers manually. The entire wiper motor will move or spin, but you can easily move the whole setup to have access to the clamp. After you attach the ball on the new wiper motor to the clamp on the linkage rod, move the wiper motor to its factory location and bolt it to the firewall. The wipers will move back to the factory location and all will be good to go.

[IDAHO 71]

Thank you for your reply.

I wasn't smart enough to mention that this is an '83 K5.

Will have another look tomorrow.

[Greenlee]

I replaced mine without removing the cowl. Just remove the 3 or 4 bolts holding the motor to the firewall and you will be able to pull it out just far enough to take the nut off that attaches the linkage to the motor.

Take heed of how the linkage attaches to the motor. It's possible to put it back on 180 degree off and it will try to turn the wipers down into the hood when you turn on the wipers. Don't ask me how I know this!

[IDAHO 71]

Thank you Greenlee. Both of these suggestions should work, although it looks a lot easier to pull the motor and get the nut on the crank arm. I was able to get a small camera in there and get a few stills.
The instructions say that "on some models" [no further amplification is offered] it may be necessary to take the motor from the crank arm instead of removing the crank arm from the linkage.
This is what I'll try, but, there also seems to be some sort of spacer or bushing under the crank arm. Is this something that has to be replaced?

[Greenlee]

Originally Posted by IDAHO 71

Thank you Greenlee. Both of these suggestions should work, although it looks a lot easier to pull the motor and get the nut on the crank arm. I was able to get a small camera in there and get a few stills.
The instructions say that "on some models" [no further amplification is offered] it may be necessary to take the motor from the crank arm instead of removing the crank arm from the linkage.
This is what I'll try, but, there also seems to be some sort of spacer or bushing under the crank arm. Is this something that has to be replaced?

I don't remember the bushing. I had my wiper motor in and out several times last year. I had the truck down to a bare cab for paint. When I put it back together the wipers would not shut off reliably with the switch. I thought it was a bad switch at first, but it turned out to be the motor.

[tucsonjwt]

I have replaced the wiper motor on a 73, 76, and 83 C20 and don't remember having to mess with any of that. I just unbolted it from the firewall and disconnected the harness. I guess I am missing something.

[Greenlee]

Originally Posted by tucsonjwt

I have replaced the wiper motor on a 73, 76, and 83 C20 and don't remember having to mess with any of that. I just unbolted it from the firewall and disconnected the harness. I guess I am missing something.

You also have to unbolt it from the linkage. But, you're right, it's not hard to do.

[IDAHO 71]

Finally got the time to finish the job yesterday.

The " bushing" I thought was there was just decades of gunk on the firewall seal.

All of the above suggestions can be done. At lease on this series,there is no need to take off the cowl.

I appreciate Greenlee's comment about the 180 out thing, it can be done.

While available, I got a coating of lubriplate on the joints. This should extend the life of all that stuff.

Thank you all for your help and suggestions.