Windshield Wiper Troubles

[PVCsnorkel]

I've been battling my wipers for the better part of a year now and I'm stumped about how to proceed.
The motor is getting power and rotates fine when it is disconnected from the linkage. But when I hook it back up it sounds like the gear starts skipping as it goes up the windshield and then stops completely and won't retract. I can push them down manually and then it'll do the same if hit the switch again.
Does anyone have experience with this issue?

 

[Spike Strip]

If your linkage isn't binding up, then the problem is probably in the Motor - There's plastic gears in there that may have lost teeth. You can remove the backing plate to have a look, IIRC. May need grease ? Parts are not available, though there was a thread some years ago where a member 'found' a suitable gear replacement. Good luck searching.

If the plastic bushing on the wiper motor arm that connects to the linkage is deteriorated, Wit's End sells an exact replacement. Otherwise, you can make NAPA 600-3505 work. Price is about the same so I'd go with the Wit's End as it's a perfect reproduction and can be used for the bushies in the rest of the linkage, too.

New motor is long NLA. Good used are available.

 

[Spike Strip]

 

[PVCsnorkel]

If your linkage isn't binding up, then the problem is probably in the Motor - There's plastic gears in there that may have lost teeth. You can remove the backing plate to have a look, IIRC. May need grease ?

I have the wits end bushing. I'm on my second as the first one got cut in half. I don't think I had it installed correctly though.
I took the gear apart and it's not missing any teeth. I tried switching gears with a spare Motor set but the gear was a different size so it didn't catch the worm gear. I'm hesitant to throw the whole parts Motor set in until I can figure how to install the bushing so it doesn't get eaten up again.

 

[Spike Strip]

That NAPA bushing is the same as Dorman 49451 and you get four of them so you've got a couple extra for the learning curve. They're not as tight as the Wit's End one, but maybe that's part of your issue?

There's a YouTube Vid of how one guy installed his NAPA set. Seems to work fine.

 

[PVCsnorkel]

That NAPA bushing is the same as Dorman 49451 and you get four of them so you've got a couple extra for the learning curve. They're not as tight as the Wit's End one, but maybe that's part of your issue?

There's a YouTube Vid of how one guy installed his NAPA set. Seems to work fine.

That's good to know. I'm going to try and grease the linkage and see of that helps, the motor gears definitely need new grease.

 

[PVCsnorkel]

I got some time to do some more trouble shooting last night and finally figured out what was going on. Since it had been a long time since i really took a hard look at the problem, I decided to forget everything i did before and start fresh. I found out that the drive gear had 3 teeth (hiding under a glop of grease) that were chewed away and that was definitely the cause of the initial problem.

I have a motor from an 81 so I went to swap that part in, and discovered there are 2 different size drive gears that came in 60s. The early one is larger and this causes the drive arm on the back side to crash into the opening in the cowl. Other than that they are interchangeable and with a little trimming i could easily make the 81 motor work. Early 60s do not have intermittent wipers like my 85 does, so I will be sourcing a new motor.
I found that removing the entire linkage set and motor to install the Wits End bushing on the drive arm is much easier than trying to install everything in place. The whole linkage and motor can be reinstalled as one piece with some careful maneuvering through the motor opening. I had to use 2 pairs of pliers to get the bushing in, one to hold a side in and another to press the opposing side into place, I couldn't have done that with all parts in place.

The most important piece I learned through this whole process is that the worm gear has adjustment to make it contact the drive gear better. I found a Mud thread talking about adjusting the worm gear on a 40 and our motors have the same adjustment! On the opposing side from the motor, there is a screw with a jam nut. If the jam nut is loosened with a 10mm wrench, then one can take a (stubby) flathead screwdriver and turn the screw in, putting more compression on the worm gear and tightening it to the worm gear. Be careful loosening the screw as there is a plastic bushing between the worm gear shaft and compression screw.
Orange is the Bushing
Blue is the Jam Nut
Pink is the screw, turn this in to tighten the gears.

I may have lost this battle, but it gave me new direction to win the war. A late model 60 motor and some 4 runner wiper arms and she should be fully operational again.

 

[CruiserTrash]

@PVCsnorkel Nice work man. FYI I have an 11/82 truck and I do have intermittent wipers. I’d consider it an early truck, heck it’s still got glass fuses like a 40. There’s a separate box to control the timing under the dash. It’s like a relay except it’s full of gears and pawls. Pretty amazing that Toyota’s solution was a tiny electro-mechanical device.

 

[PVCsnorkel]

@PVCsnorkel Nice work man. FYI I have an 11/82 truck and I do have intermittent wipers. I’d consider it an early truck, heck it’s still got glass fuses like a 40. There’s a separate box to control the timing under the dash. It’s like a relay except it’s full of gears and pawls. Pretty amazing that Toyota’s solution was a tiny electro-mechanical device.

Thank you.
Good know about the intermittent wipers, I guess they do all have them then. The older electro-mechanical solutions are much more interesting and impressive than new electronics in my opinion.

 

[CruiserTrash]

@PVCsnorkel I'm just a geek for rube goldberg stuff like an electro-mechanical intermittent wiper timer haha.