Wouldn't it be totally wrong for a company to design a transmission that will allow a car or truck to freewheel in any gear? Total safety issue, and according to the California VC book you can't ever allow a car to freewheel down a hill, so it would be illegal, if you ask me.

What happens if you are coming down a long grade in your f250 camper special with your kids in the camper and boat on the back, are you supposed to use 2nd gear all the way down or ride the brakes?

I never heard of overrunning freewheeling in any trans except for the BW 3 speed with OD, (when IN OD), like came in early T birds, (which I could be wrong on that one, it's been a while since I rebuilt one of those.), and now that SAAB that woodz428 referred to.


Later, mikey

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BE different....ACT normal.

No one is completely useless..They can always be used as a bad example

These comments raise many issues with your original post and could have a bearing on any transmission discussions. Since the Cleveland engine was last produced in 1974 and none were in Pick ups, your comment opens a bunch of questions?? If it is a 351C as you claim, it most likely doesn't have a C6 behind it in a 1977 truck. A 351C will only hook up to a smallblock pattern,at that time it would have likely been using an FMX...NOW... a 351M( heads similar to a Cleveland) was available and likely used a C6, which it shares with the 460.... That raises the question regarding the 1985...was it a Windsor, or a Modified?? A Modified could have had a C6, but the Windsor would not.

I have FREE WHEELING on my 32 Olds. The feature as I remember it was in the torque converter. It was not called free wheeling, but I don't remember what it was called.

You have a 1932 Olds with an auto?? "the feature as I remember it"??? If you HAVE it....why would you need to rely on memory, couldn't you just go out and check it? I'm working on a '36 right now, I didn't see that in the manual, I'll look again..I thought that Chrysler was the first in the 40s with an "automatic" type tranny. A lot of early cars had "hill holders",which is an entirely differnt item used on stick shifts. But I don't recall that early of an Olds auto. If it has it(freewheeling) ,it may because that was a VERY EARLY attempt and they were LEARNING. That is still not any type of evidence the comments you made regarding the C6 have any validity...without evidence to back it up ..even the '32 auto is hearsay. Since I have numerous early Olds manuals to reassemble this '36,I can verify, or not, that comment easily as the C6.

I just researched through 6 older Olds and various transmission manuals dating back to the late 20s and the earliest Olds auto they list is a 1940. You may have had a freeweheeling system on a stick , but there was no auto available that year. Free wheeling( regardless of what "trade name" is used) is not new as I mentioned earlier, and may have been a common device in early cars. But we were of course referring specificly to a C6 and any conversation regarding any other vehicle/trans is a little of a diversion. Just supply some form of documentation to your claim and you can verify what you say. Otherwise it is, as I said..hearsay..not something that anyone diagnosing a C6 trans should take as true.

WoodZ428, I think most people who post on this site strive for accuracy.

In my opinion, it seemed that fast68 was getting somewhat frustrated because he felt was not getting the information he needed.

In my opinion, some of the info he was posting, in regards to his truck having no engine braking, whatsoever, were a little over the top, as an effort to get responses to his post. And he did, so it worked.

WoodZ428, you should reread my post, especially the part about differential ratios. You corrected nothing. In fact you were in error when you posted what I had said. Read my post again and you will see.

If his sprag was locked up in the torque converter, it would generate so much heat that it would have the fluid smelling like rotten eggs.

Fast 68 said his trans worked fine, but there was no engine braking in high gear. He said nothing about the trans slipping, band, clutchs etc.

I stand by what I wrote, there is nothing in a C-6 that will give it engine braking in high gear.

At highway speeds if he let's off of the gas pedal he will feel something starting to slow the vehicle down, these things were outlined previously, but there is no componet in the trans that will make this happen.

I believe he said that it wasn't slowing down.. the engine just dropped to idle with no braking effect( I just reread it and that is what he said). He didn't even verify which tranny he had as I pointed out later. You can stand by what you have said, but that doesn't make it true..again..It would seem from your proposition that all 3 of the current C6 transmissions I have are all somehow defective and have been for between 40,000( on one) to 78,000 on another.So with first hand experience, I respectfully have to say that you are completely wrong. Any of the components I mentioned were possibilties, and still are, if it was a C6, but I think he had an AOD after reading the post again.
The slowing down is what is referred to as engine braking...and it is the torque converter that creates it much the same as a clutch, although it is a fluid an not mechcanical device. Torque converters have a stall speed, that's where the engine can't rev anymore when the brak is held to prevent motion...that is what creates the engine braking on decceleration. I'm not sure which post you are referring to, but if it is regards to the gearing of a truck... you have it backwards...if you have, same as said before, a Higher numerical gearing( which is what most trucks have in comparison to cars) you will get more engine braking instead of less, which is what I corrected.. and it hasn't changed unless the laws of physics has been altered.

I see part of our disagreement. In post #4, I state that he may have a high final drive ratio differential, I then go on to say that this would mean a low numerical rear.

Perhaps the word ratio should have been left out, although the following words, low numerical rear, should have made it clear enough.

In post #9 I write, that a high numerical differential would have a greater impact on the amount of drag or resistance that he would feel.

Which should more than intimate that you and I are saying the same thing.

At least as far as that issue goes.

Will you tell me the final drive numbers that are in these c-6 equipped vehicles that you own, perhaps that may shed some light on why you feel the engine braking that you do.

And yes, you are correct, the torque converter does play a part in slowing the vehicle down. Unless he had a very loose converter in this vehicle[high stall], then that may explain why his engine rpm's go back to idle speed.

But there is nothing in the c-6 trans that will give you an engine braking effect in high gear. Nor is there any type of coast device in the c-6 that will allow the trans to just glide along when you take your foot off of the gas pedal.

When the output shaft is going faster than the input shaft, the trans can overrun. For an explanation of this, go back and read post #9, but really read it this time.

In high gear the trans is 1-1, so after you overcome inertia and you are cruising along and then you lift off of the gas pedal, you may not notice the slowing down effect that the rear and torque converter will allow, at least for awhile, depending on your speed, the amount of stall the converter has, or the final drive numbers.

I suppose that upon closer examination, you and I don't have much to disagree about. Thank goodness the laws of physics haven't changed!

[QUOTE=briscoe] Will you tell me the final drive numbers that are in these c-6 equipped vehicles that you own, perhaps that may shed some light on why you feel the engine braking that you do.

QUOTE]
The gear ratios are 2:78,3:00 and a 3:50. I would like to add that what you feel when down shifting from high to second( when slowing) IS engine braking. I am not sure what you keep referring to as no components that would make it engine brake...all the same components that move it forward create the engine braking. If it didn't you would get a freewheeling, which is an overrun. As long as the hydraulic system is functioning correctly, the clutches aren't worn out and the bands are correctly adjusted there is "engine braking". If the shift from high to second isn't enough to convince you take one out and shut the engine off at speed as it is decelerating from engine braking, turn the igntion back on. Unless you wait until you are about stopped, and it may still work, the engine will fire back up. At some lower speed you can feel it "disengage" but that's after initial slowing to maybe 25MPH and when the engine is shut off and no longer operating the hydraulic system. That illustrates that the engine is being turned by the wheels..i.e. engine braking. The same applies if you run out of gas while driving (happened a couple of times in the Deuce because of a gauge calibration), as gas gets caught in the tank pickup it will be pumped to the engine or by just pumping the accelerator it will light up again.. again illustrating that the engine is being rotated by the drive train..i.e. engine braking. Maybe you aren't discussing engine braking and are using the term to describe something else..like lock-up?? Early autos had a rear pump that allowed you to push start a car,but that was later phased out. Maybe that's what you are referring to as engine braking?? I think you can see by my 2 examples that the engine continues to be turned by the drivetrain...which is what the term "engine braking" applies to..the engine "brakes" the vehicle .

WoodZ428, you state that a downshift from high to second is engine braking, I also pointed out that you will feel engine braking in 2nd, so good, now we've both said it.

You in your last post and me in post #9.

Which is why I think you have not read my post's very carefully.

From a technical standpoint, I will admit, you make a strong arguement, your no dummy.

And from a technical standpoint, when I say there is no component in the trans to cause engine braking in high gear, I mean there is no clutch that comes on, no sprag that locks up, no servo that applies, etc, just for engine braking. Of course he should feel resistance in high gear, when he comes off of the gas pedal.

Of course the vehicle should slow down when the foot comes off the gas, and for reasons that I have explanied and you as well, this will vary depending on a lot of variables.

I said in post #9 that if he were driving at 60 mph and let off of the gas, the rear would then start to drive the trans and engine as well, thus creating drag.

It seems that you want to split hairs on this issue, yet you don't seem to want to take the time to throughly read thru all of the posts completely.

Fast68 stated in post # 5 that "he felt no resistance whatsoever", he then goes on to say "as do all the ford trucks I have been in, or driven in the past and that also ran fine, like mine does"

This was after I had posted that he may have a lower numerical gear rear and perhaps that is why he felt no engine braking.

Did I just say engine braking, well I guess I did.

So I will ask you, do you think all of the fords that he has driven, including this one he posted about, really had no engine braking in high gear?

Or do you think he just really couldn't tell? And this is no insult to fast68, maybe he can't feel the engine braking in high gear like you do, with your Fords. Perhaps his level of awareness is not as great as your's.

He did understand, when I suggested in post #4, the reason he did not feel engine braking may be because he had a lower numerical rear gear, because he replied that he had a 3.50 final drive.

I own a Transmission shop, I drive cars and trucks every day, I have worked in transmission shops since I was 17 years old.

Of course I know what engine braking is. Please don't split hairs with me.

You are obviously a smart guy, I know it is a pain sometimes to read thru all of the info posted but, If we are to be accurate we must take the time.

Don't know if your done or not, but I'm about tired of this. Good luck to you.

Im not going to debate engine braking but C6 small block truck transmission was installed untill 89 in certain trucks ie f250 and yes I owned one and changed it out to an aod for gas mileage.

I wasn't going to post on this again, because it was obviously headed nowhere. I do appreciate the comments about the C6 availabilty in trucks, I wasn't sure when they were phased out.
I do know, however, that all the Ford tech books use the term "engine braking" in the diagnostic chart. As in, what to look for if it is NOT engine braking. So regardless of what someone may preceive, according to the makers of the transmission..it has engine braking, or they wouldn't be telling you how to diagnose the lack of it. 10 Ford Tech manuals from the mid 60s to the late 70s all have the same wording. I know, I know, they only designed and built it, so probably have much less knowledge than any others..I understand my shortcomings, I use incorrect Factory publications instead of getting all my info from other souces..My Bad.

Ok, another guy with NO trans savy has a question. In the above quote, he states the engine "returns to idle". To me, this would mean that the trans is somehow unloading and freewheeling, letting the engine idle down even when going 60.

From my own experience with a GM od in my wifes old LeSabre, it did the same thing on long hills. I would let off and watch the tach drop from 2200 to 1300, then down to 600, then back up and back down, all the while picking up speed flying down Sunset point (Tony will know the hill! LOL)

Granted, with OD and very low numbered gears, the "affect" of engine breaking will be very hard to detect, but should the engine return to idle once he lets off the gas going 60?

Mark

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Lets just hope the "change" that we think we are getting does not end up being just "chump change"!

I think he came back, read this whole thing and then realized he was in the same boat here! LOL

Mark

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Lets just hope the "change" that we think we are getting does not end up being just "chump change"!

Woods 428, I am sorry you misunderstood.I have freewheeling on my 32 Olds so I know what it is,and it is a standard. The feature as I remember it was referring to my fathers 79 Lincoln.