explain free-wheeling to me

[p24-1953]

i was reading the b&w overdrive man. on this web site and came across this

"at speeds below the oversrive cut inpoint the free wheeling action of the unit makes it possible to do all gear shifting without releaseing the main clutch" so if i slow down to 20 in third i can just lift off the gas and shift to 2nd?

what exactly is free-wheeling used for?

[greg g]

Free wheeling was promient with 2 stroke powered cars like SAAB and DKW. Back in the dark ages, these cars depended on oil mixed with their gas to provide internal lubrication.

So the amount of throttle opening determined how much or the mixture entered the engine. All well and good for acceleration and for cruising, but detremental to lubrication when slowing down from speed or running down a hill with the engine turning high rpms but not getting much lubrication because the throttle was closed so no fuel oil mix was reaching the engines internals. This was not a good thing. However, this feature did not allow for engine compression braking, putting all the load on the cars brakes.

There was a term some time ago called Greogia Overdrive which referred to the practice of shifting a car or more likely a HD truck into neutral going down hills. Using gravity to keep the momentum of the of the vehicle but reducing engine drag. Essentially freewheeling, Some luxury cars in the 30's had freewheeling to reduce noise when coasting or running down grade, but these were selectable if engine braking was desireable or necessary.

With the planetary gears of the OD, if the wheels are spining drive shaft faster than the engine, the overspeed will disengege taking the strain off the drive line allowing a shift to be made.

Thats the theory, but I don't know how it works in practice, or if it can be overridden.

In my stash of stuff, I have an old cable control that is marked freewheeling, I have no idea what it is from, but my guess is that it is somehow related to and OD equiped vehicle.

[Rodney Bullock]

I rode in a 1933 Graham about a year ago. The guy said it had this free wheeling as an option. He drove the car and changed gears without hitting the clutch. I was scare to death because I have never heard of anything like it. he did it how ever for some reason you can't do it all the time the planets have to be in alignment or something.

[james curl]

Free Wheeling

There is an overrunning clutch, which consists of a group of rollers in a cage, when power is applied the rollers move aginst the cage and transmit power to the driveshaft. when the power is taken out, as in no throttle, the rollers loose their grip and slide allowing the driveshaft to rotate faster than the transmission gears. The transmission gears now are running at engine speed and you can shift without the clutch, but you cannot stop without disengaging the clutch or the engine will die. That is as simple as I can state how it functions.

[Rodney Bullock]

Thanks James great explaination

[Jim Yergin]

In my stash of stuff, I have an old cable control that is marked freewheeling, I have no idea what it is from, but my guess is that it is somehow related to and OD equiped vehicle.

Greg,

My understanding is that in the early thirties, freewheeling was a popular feature on cars. It was promoted as increasing gas mileage since the car would coast in freewheeling. However it also meant no engine braking and more reliance on brakes to stop. It was a feature that did not require an o/d transmission. Your cable is probably from that era. I think the early Plymouths had it.

Jim Yergin

[Tim Keith]

It is sometimes called a sprag clutch. In practice it is similar to a rotational

ratchet, like inside a common socket wrench.

http://en.wikipedia.org/wiki/Sprag_clutch

[JIPJOBXX]

I had a 1931 Studebaker with free wheeling and just like someone stated here you didn't need the clutch to shift. It was different all right but it was just like driving a car in neutral when it was in gaged. I really do not know how it worked but it did. Jon

[Don Coatney]

Free wheeling in it's most elementary form is removal of the mechanical link between the engine and drive wheels.

Can be acheved by placing the transmission in neutral gear on most all vehicles, depressing the clutch pedal on a standard shift automobile, taking you foot off the accelerator pedal on some (not all) overdrive equipped vehicles etc.

[Don Coatney]

I rode in a 1933 Graham about a year ago. The guy said it had this free wheeling as an option. He drove the car and changed gears without hitting the clutch. I was scare to death because I have never heard of anything like it. he did it how ever for some reason you can't do it all the time the planets have to be in alignment or something.

Rodney;

I can shift gears in your Plymouth without using the clutch and you will never know that I did not use the clutch. Nothing magic about it. Just knowing how (and when) to do it. Let me drive it next time I see you and I will teach you how to do it. I have been doing that for years. Free wheeling is not required.

[55 Fargo]

Rodney;

I can shift gears in your Plymouth without using the clutch and you will never know that I did not use the clutch. Nothing magic about it. Just knowing how (and when) to do it. Let me drive it next time I see you and I will teach you how to do it. I have been doing that for years. Free wheeling is not required.

This is correct, I have even down shifted without a clutch, right rpm, syncrho trans no probelm. I have shifted my 47 a few times from 2 to 3rd without using the clutch with no issue

[TodFitch]

...snip...Some luxury cars in the 30's had freewheeling to reduce noise when coasting or running down grade, but these were selectable if engine braking was desireable or necessary. ...snip...

I guess Plymouth was a luxury car: Freewheeling was an option on Plymouth in the early 1930s. And in 1933 and 34 there was also an optional vacuum actuated automatic clutch. I generally keep the freewheeling control on my 1933 in the disabled position.

[Captain Neon]

Rodney;

I can shift gears in your Plymouth without using the clutch and you will never know that I did not use the clutch. Nothing magic about it. Just knowing how (and when) to do it. Let me drive it next time I see you and I will teach you how to do it. I have been doing that for years. Free wheeling is not required.

I've been able to do it sometimes when I was teenager w/ my father's Ranger pickup, but I wasn't very good at it. I'd be interested in learning this technique. You should make a video when you teach Rodney then more of us can benefit.

[knighthawk]

A few years ago I fixed up a '59 Chev Apache truck,painted it lite blue with Ivory trim , very pretty, anyway, I put an overdrive in it. I think with the overdrive engaged, whenever you let up off of thegas, the truck would start coasting , or, maintain the same speed . Supposed to be better gas mileage but kinda scary going down hill ! But, I think all you have to do then is to sis-engage the overdrive. Last I heard the truck was over in the Houston Texas area.....wonder what happened to it..........

[blueskies]

The free-wheeling clutch in the R-10 overdrive sort of acts like a synchro too. With the lockout cable pushed in, which allows the system to freewheel when the OD is dis-engauged (under the cut-in speed), I can shift into first gear without stopping the car.

Pete

[steveplym]

That is interesting Pete I didn't notice that. Makes it nice though when you are rolling thru traffic. Don't have to come to a complete stop and tick off that guy behind you.

[knuckleharley]

>>Some luxury cars in the 30's had freewheeling <<

My "luxury" 1931 Plymouth business coupe has Free Wheeling. Or did have when it left the factory. The free wheeling stuff was all in the trunk when I got it. It may have been popular in areas with small hills,but losing your engine brake could be deadly in the mountains.