GN windshield wiper question

[TC Chris]

Hey, GM fans,

The wipers would not work on the '61 Chevy. I spent a while this a.m.fiddling with them; no luck. Then I went to drive the car again and they struggled to life.... and will not go off. I finally yanked the tan wire the shop manual referred to. The manual shows a relay, likely internal... probably for the park cycle when you turn them off? Any quick fix ideas? For now, it it rains, I can just plug the wire in, but they wipers are not down in the park position.

Chris Campbell

[electra225]

You wrote "GN" in the topic, so I thought maybe you had bought a hotrod Buick!

There is a switch inside the wiper motor, where the wires go in, that sticks, then the wipers may not work, or they may not quit working. I don't know when this started exactly, but my guess is in 1959 when Buick went to electric wipers. Chevy may have had them in 1958. There is usually two screws that hold a phenolic cover over that switch. The wiper motor needs to be removed to do this on a Buick, not sure about a Chevy, but I'd guess similar. That switch is the speed switch. When you move the knob for the wipers, that switch is engaged in the appropriate position. The dash switch can be wonky as well, but that's lots more rare.

[TC Chris]

"GN" = the attempt of a fumble-fingered typist to ID the car maker. You'd think that somebody who has lived in Michigan since he was 4 could get it right.

The Chevy's wipers began their obsession with "on" as I was driving a mile and a half down the road to meet a guy who has a magnificent '35 Chevy coupe hotrod. He is a neighbor of a friend and his wife gathered my phone no. yesterday so he could give me advice on--ta-da!!--Buick restoration. He retold the old story of how the Buick straight 8 was THE hot engine in the 30s. So all the stories merge. His Chevy coupe was so perfect that I did not actually touch the vehicle.

For the time being my Chevy's wiper motor is unplugged, so if it rains, all I have to do is jump out, open the hood, and plug them in.

The transmission shop installed the new vacuum modulator today. That should solve the leak issue but "deleted", now it shifts worse. The shift (singular, there's just one on a Powerglide) was perfect before: fast and hardly noticed in ordinary driving. Now it kinda slides from 1 to 2. I'll observe for a little while and then inquire if it keeps up.

Chris Campbell

[Firedome]

I wouldn't drive a rust-prone rare '61 Chev convert in the rain anyhow!

The Buick Century (100 mph) of the late '30s with the big Straight 8 is considered by some to be the 1st US muscle car.

[electra225]

I have a piece of electrical tape on the terminals of the wiper motor in my Buick. I don't want the wipers to haze the glass. I use Rain-X on the glass, so wipers are unnecessary unless it's pouring, then I pull over and wait it out. Chris, get some Rain-X and try that. You'll be amazed at how well it works. I use it on the windshield of my Mini, as well. I've had it 9 years and the wipers have been on once, right after I got it.

There is an adjustment on the vacuum modulator. You pull off the vacuum hose, then using a thin-blade screwdriver ( the one you have to adjust the balance control on your Magnavox stereo) and then adjust the modulator. I forget which way is which, but you need to get that adjusted and the shift points sorted, or you may be rebuilding your Powerglide again. They are not supposed to slip when they shift. The vacuum modulator regulates the fluid pressure. IF the pressure is too low, the trans will slip, since there is insufficient hydraulic pressure to engage the direct drive band. Powerglide transmissions still had bands. The Turbo-Hydramatic jobs introduced clutches. Adjustment is typically done to a modulator when they are installed. You put it on, take the car for a drive, raise it up on the hoist, adjust, drive again. You do that several times if necessary so you get it right. Properly set, your Powerglide should smoke the rear tires, even with a 283. The bracket racers used to get good times out of an old Chevy with a Powerglide. They were bullet-proof transmissions, very popular, millions of them were built.

A Buick straight 8 conversation may be killing your topic, but since you mentioned it.........

Grandpa went to his grave swearing that not only was the 320 Buick Straight 8 a blessing from God, and the finest powerplant known to man, but that he could coax an '"honest" 300 horsepower from one. He had a '37 Century that he used to haul homemade "soda pop with the foam on top" to friends and customers, always at high speed, in neighboring counties. His Century had been bored to the water jackets, then resleeved. He ran Mallory ignition, an Offenhauser "3/4" cam. Induction was courtesy of eight Winfield 97 carburetors. Exhaust was by homemade headers, exiting right in front of the side mounts. A tad noisy, to be sure, but it ran like a scalded dog. He would bore and stroke a 320 to 414 cid and put them into International trucks. Grandpa's buddy Morris could haul a load of 400 watermelons in his old KB-8 at 45 mph, using Buick power. That was truckin' for that day and time. It took a diesel to better that.

[TC Chris]

There is an adjustment on the vacuum modulator. You pull off the vacuum hose, then using a thin-blade screwdriver ( the one you have to adjust the balance control on your Magnavox stereo) and then adjust the modulator. I forget which way is which, but you need to get that adjusted and the shift points sorted, or you may be rebuilding your Powerglide again. They are not supposed to slip when they shift.

Where's a adjustment--inside the vacuum nipple, or inside the transmission-side nipple? There's no external access other than those two ports. The car was shifting perfectly before the new modulator went on, even though the old one had a damaged diaphragm.

Chris Campbell

[electra225]

Inside the vacuum nipple. You take the vacuum hose off. You should be able to see a slotted screw head. You turn that in or out to adjust the shift point. If it was shifting right before you replaced the modulator, there is not much argument about what the issue is likely to be. That used to happen a lot, particularly on Fords.

[TC Chris]

I'm pretty sure that the little control rod/transfer rod is missing on my transmission. I was looking at online discussions and that's what transfer the diaphragm action to the transmission's action. This is so frustrating. It was shifting perfectly with the old leaky unit.

Chris Campbell

[electra225]

Who did the work? I'd speak with the shop that did the work and let it be their problem, which it rightly is. Good luck.

[TC Chris]

Hard to travck it down. The engine rebuilder had a buddy fiddle with it and pretty soon after I got it back it was leaking badly. The shop that rebuilt it after that had to call Dad out of retirement to deal with a Powerglide. The son has been good about follow-up. I'm trying to engage in problem-solving, not fights. The car was shifting perfectly before the modulator exchange and I don't care whether the mod is doing anything if the car is shifting nicely. Not sure why replacing the mod. would have made the shifts squishy unless the pin dropped out in the process. And I was there and didn't see it on the floor. Or in the old mod unless it was hiding. I might settle for a band adjustment to make it shift precisely and call it good until I can hunt down the missing pin. I'm just tired of fiddling and want to be able to drive.

Chris Campbell

[TC Chris]

UPDATE!! I had worked myself into a complete lather this week. A summer car I couldn't drive because the transmission would slip-shift itself to death; missing tiny rods; aargh. But I did not call the transmission shop until today. Good thing. Suddenly last night it dawned on me: hey, the transmission shifted perfectly before we replaced the modulator, and afterward, it shifted in a gentle glide. Geez, that means the modulator is doing something! I.e., it's connected! No missing relay rod. So as soon as I got to work I went to the Fatsco Transmission page and pulled up the diagram of the '58-'61 Powerglide. No little pin or rod shown. Maybe it's part of the transmission??

So I reached the guy at the shop this afternoon. I didn't yell about missing pins or other disasters. I just said "It's shifting worse now, gliding into 2nd." And he said, "Oh yeah, I've just got to turn it in." You mean the modulator adjustment, through the vacuum port? "Yeah, the line pressure is too low; I can turn it up through the vac. port. It's OK to drive but not for a long time because it will wear."

So yes, Greg was right, it's adjustable. No, the online sources were wrong, there's no loose pin, and the effect is on shift quality, not shift point. Whew. I'm so relieved. This will not occupy my brain when I wake up at 5:00 a.m. to pee.

Lessons: Ask around. Apply critical thinking skills. Don't panic.

Chris Campbell

[electra225]

The Internet is a wonderful invention. But when it comes to the Powerglide in a '61 Chevy, my old MOTOR manual from that period is better. I have been kicked by that mule before, Chris. It seems like I always learned best at the toe of someone's boot........

I'm sorry a situation with an apparently simple solution caused you so much grief. I'm also sorry that the outfit that rebuilt the transmission did not provide, and properly adjust, a new vacuum modulator when they rebuilt the transmission.

[TC Chris]

The modulator he got was the wrong one (threaded end too big). He was waiting for the right one. I got one from Fatsco before he found one. The transmission behaved perfectly with the old one in place but it was leaking. Maybe after Monday's visit I can move on to other issues. Like rigging an under-dash switch for the windshield wipers. And it would be nice to get the heater core out. I've got it bypassed now. Nobody makes one for the '61 so if that's the problem, I'll have to locate a real radiator shop. I'm hoping that maybe it's the heater valve--this car uses a fluid shut-off valve, not just an air door. I have driven the car in winter temps and it's surprisingly comfortable without the heater.

Chris Campbell

[electra225]

Installing an under-dash switch for the wipers won't fix your problem. The problem is in the wiper motor assembly itself. The wiper motor assembly should be rebuilt. They might even still be available at a parts store. They used those motors well up into the 1970's on the big GM cars. If you wire around the original wiper switch, you may find you have the same problem, only now you have made a mess. Remember the grease that turns to glue in record changers? Same thing with wiper motors. I would probably remove the wiper motor assembly, take the cover off the relay assembly, then see if I can free things up in there before I went out and bought another wiper motor. You may ultimately have to buy a rebuilt assembly, but have little to lose by trying to remedy the situation yourself. To remove the wiper motor, you raise the hood so you can access the bolts to the panel with the ventilation holes around the windshield wipers. You remove the wipers, then remove that panel. That gives access to the wiper motor transmission. You remove a nut from the end of the motor shaft, then the transmission falls off, just a slip fit. Then three bolts holds the wiper motor to the cowl. You assemble back opposite of how you took it off. Good luck.

[TC Chris]

My plan sounds a lot faster: get two connectors that match the push-on spade job that plugs onto the motor assembly. Solder or crimp them onto wires. Run wires through the firewall to a switch. I know, it's 2nd best or worse. But other issues need attention first, and besides, how often am I going to be driving the Chevy in the rain anyway?

Chris Campbell

[electra225]

Hence my suggestion of trying Rain-X.

[TC Chris]

Update on the Powerglide.... Took it to the shop on Monday at about 4:30 when he had cleared a stall. He tried adjusting the vac. modulator and it did nothing, so after 3 tries he pulled the vac. mod. off, looked at it, and it was not the adjustable kind. The wrong one that sits in the trunk is adjustable, but not the right one for the cast-iron trans.

It was not the best time-- it started pouring rain so when I drove up down the road to test, it was noisy and besides, my windshield wipers don't go on unless I raise the hood and plug them in. So I was driving kinda blind in a thunderstorm. On the ride back to the Chevy's garage, I did plugged the wipers in like a civilized driver..

He handed me the pin that the modulator activates. It's there and it's much bigger than online sources suggested. But it just doesn't solve the sloppy shift problem that did not appear until the leaking mod. was replaced with the new one from Fatsco. Maybe it's a tolerance problem and the pin is too short for the new device. Maybe the new device is defective. Or maybe its another issue altogether.

Would the throttle-position rod adjustment, the one from the carb linkage, affect shift quality? The transmission does not kick down under full throttle and hasn't since the rebuild, which makes me wonder about the linkage length adjustment. Or maybe band adjustment? All I know is that the leaky mod. gave very nice shifts and the new one is all loose.

The shop guy was going to call Fatsco and ask them what they think. I'm going to call him and remind him tomorrow. The squeaky wheel....

Chris Campbell

[electra225]

You are having an issue that does not lend itself well to online communication to resolve. Sounds like eyeballs on the situation may be the correct solution. It also sounds like they are on the case, which is encouraging in itself. The MOTOR manual shows that linkage from the carburetor, but does not adequately (for my aging brain) explain what it does, exactly, only how to adjust it. My GUESS (!!!) is that it does affect shift quality, since it affects kickdown. It has been 25 years since I laid eyes on any Powerglide, and it was a '62 aluminum case job on a 327. TH 400 uses an electric solenoid, operated off the gas pedal for kickdown. The TH 350 uses a cable for the same purpose. Dynaflow had a linkage that controlled the accumulators to control torque converter pitch. There was no kickdown, per se, since Dynaflow does not shift. It is possible you have the wrong modulator, the "new" modulator is defective, or that you have another issue altogether. If the rod is there, it should be the right one. So that is not likely the problem. My best advice is to keep us advised, but also let them work thru this. Cast-iron case Powerglide is not something they work on every day, most likely. Give them time to do their research, work with their vendors, along with some time to tinker. I understand your concern and frustration. I had the rear end rebuilt in my Buick two years ago. The estimate was $1000. By the time it was done, the bill was over $3400 dollars. I didn't believe their estimate, so I "laid by in store" for the event. The driveshaft was so bad, it had to be reproduced. Bearings had to be made for it. We become impatient when things don't go as we'd like repairing old cars, but we need to be grateful anybody will work on one at all. Good luck.

[TC Chris]

Give them time to Windsor do their research, work with their vendors, along with some time to tinker. I understand your concern and frustration. I had the rear end rebuilt in my Buick two years ago. The estimate was $1000. By the time it was done, the bill was over $3400 dollars. I didn't believe their estimate, so I "laid by in store" for the event. The driveshaft was so bad, it had to be reproduced. Bearings had to be made for it. We become impatient when things don't go as we'd like repairing old cars, but we need to be grateful anybody will work on one at all. Good luck.

I am endlessly patient. It's hard when you don't live where the car is and have to wait for vacation days to attend to it. But losing patience usually doesn't help much. My theory is that I don't want to be the guy who makes them cringe when I walk through the door or call on the phone ("Oh "deleted", it's him again."). Better to be the guy that they want to make it right for. What I really want is for Pat to call his dad back in (he did the rebuild since the current owner is only 33, and the transmission was already 28 years old when he was born).

Some Michigan fun: while I was there he paused under the car to take a call from his dad. He was puzzled why dad had driven through Sebewaing on his way back from Bad Axe. These are towns in Michigan's Thumb. And after passing Sebewaing, dad would have driven through Quanicassee. If you think somebody is just posing as a Michigan resident, ask 'em to say "Quanicassee."

My Dad used to conduct what were the called Crippled Children's Clinics in Bad Axe. The state sponsored them but Dad refused the pay because he felt it was his obligation to help poor kids who could not afford medical care. Once he limped home in the '56 Chrysler Windsor, the Chevy's immediate predecessor. The car would not attain any speed over a crawl. Turns out a stone had flipped up and dented the fuel line. Odd what you remember.

Sebewaing had a brewery in the days before consolidation (and long before local breweries made a huge come-back). Sebewaing Beer had a flying ringneck pheasant as its symbol and there was a large mural of the flying pheasant on the brick wall of the building there. Pheasant hunting was a big deal in the '40s and '50s before changing farming practices eliminated habitat and reduced the population of the birds.

Chris Campbell

[TC Chris]

Update on the wipers. The wind is from the NE and waves are rolling in for the second day, so it’s not a day for solo sailing. But I had switched the Mustang for the Chevy last night with a goal of making up a remote switch device for the wipers so I would not have to hop out and plug them in under the hood when it started raining. I bought some push on-connectors, male & female, in a size that looked to match the car’s connectors. Yup, they fit. And I had an old push-pull switch from an old family friend’s estate. It has a little walnut hand-turned knob he must have made on his lathe. So I made up my remote switch cord, crimping the push-ons at one end of the wires and ring terminals for the switch at the other. There was a convenient firewall hole. I made a little steel bracket to hold the switch under the dash since there were no existing holes that would work. Put it all together in the car.
I flipped the ignition to “on” and the wipers made a single pass and parked themselves very nicely. And refused to come on again…. AArrghh!!!! I went from no wipers at all for the first two years to all wiper, all the time briefly a couple weeks ago, and now back to no wipers at all. Yeah, there’s voltage at motor. Just no action.

But I have a very nice remote switch for when they end their strike and go back to work full time.

Chris Campbell