"Overcenter" Feeling with Low Speed Pedal

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Model T Ford Forum: Forum 2015: "Overcenter" Feeling with Low Speed Pedal
Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul O'Neil, Fullerton, CA, USA on Wednesday, January 28, 2015 - 05:22 pm:

On another thread about my feet being large and the shoes fouling the pedals I mentioned that the low pedal had become stiff as it started to tighten the low speed band. It takes more & more pressure to move the pedal and then it SUDDENLY moves and tightens the band with a bang. This caused me to stall the motor twice at one intersection. Thereafter I used more revs to compensate for the lack of dexterity with the point of engagement.

Sunday I adjusted the bands again. I only gave the low speed band a 1/4 turn as I was afraid of adjusting it so tight that there would be very little "neutral" left in the pedal. On a test drive I thought at first that the pedal was better and more linear but by the end of the hour long drive the engagement with a bang seems worse than ever. It makes starts unpleasant, not a good thing in this suburban rapidly going urban area.

Below are four pictures all shot Sunday. Can you spot something I got wrong?

Vintage Paul








Top of pagePrevious messageNext messageBottom of page Link to this message  By Nathan Fahrni on Wednesday, January 28, 2015 - 05:36 pm:

I had a similar issue a couple years back with my father's car. I had to keep adjusting the low band up and up, but the pedal kept on getting closer to the floor the more the car was driven. I kept thinking "I'm not that hard on bands, am I?" But no more band material was gathering in the screen. Eventually I discovered that the pin holding the internal cam on the pedal shaft was shearing off allowing the cam to be "clocked" wrong. Luckily I caught it in time before the pin sheared completely off. Being the engineer that I am called the Model T parts supplier and asked them what the grade of the pin was. They in turn called their mfgr. who told them it was basically equivalent to a grade 2. From the pics it's hard to tell, but the pin looks newer not saying that is your problem, but if you have a binding issue you might want to check there. With the inspection cover off if you push the pedal you will be able to see the pedal shaft and cam moving at different rates if that is your problem.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Noonan - Norton, MA. on Wednesday, January 28, 2015 - 09:28 pm:

Paul, is it possible that the washer you have on the neutral clevis yoke is somehow getting bound against the Bendix cover? I have the washer on the other side of the rod, before the cotter pin.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth from NC on Thursday, January 29, 2015 - 06:39 am:

It's quite the conundrum Paul. With the cover off, if you press the pedal by hand: do you get a steady tightening of the band?

Nathan has a good thought. I'd work the pedal by hand and really watch and see what the cam does. Especially if that pin is something you've replaced.

My other thought is that whatever is binding up your clutch pedal isn't necessarily the band. It's hard to tell in the photos but maybe the yoke like John mentions is binding somehow? You might could swap the ends by rotating it 180*, that way the pin goes through the clutch pedal and the bent arm goes into the clutch arm from the right (or comes in from the center).

Definitely keep us updated - I want to know what the problem ends up being.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Thursday, January 29, 2015 - 12:07 pm:

Does it stick with the floorboards out? Sometimes a pedal will stick to the floorboards when it is depressed.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul O'Neil, Fullerton, CA, USA on Thursday, January 29, 2015 - 02:45 pm:

I believe the pedal is locking up with the drum well before it reaches the floor and this problem is more related to a stiffness that has developed since I got the car on the road in the last few months. I put it together mostly by myself and may well have messed something up.

I have little experience driving a T and some of my trouble has been due to poor driving technique, other problems are due to things that still need to be sorted with the car. I think this is one of the later. Basically I'm reluctant to adjust the low band too tight for fear of loosing any neutral space.

I have not had a feeling that the pedal has been getting closer to the floorboards. I had the hogshead off when I rebuilt the motor two years ago. It was machined for seals. Would the shop have replaced the pins then?



Are the pins seen here 1 or 2 the ones we are speaking of?

Right now I can't remember why I put the washers in on this side of the link. Possibly I had some idea of trying to trap oil in the joint, a reason I have put washers in many other parts of the car. In this picture, the washers sure look like they are out of place:



I will get another chance to work on the car this coming Sunday and will check to see if this washer, link or the floorboards might be binding someplace.

After all of the trouble I have had with this project over the last decade or so, I have to say that I am delighted to have narrowed the issues down to niggles like this. I am hoping to have this Flivver ready for its first club tour on St Valentine's Day. That's progress!

Vintage Paul, hopeful that we are getting close . . .


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Weir Atascadero on Thursday, January 29, 2015 - 03:04 pm:

Paul; First observation indicates the engine is too clean to operate normally. sarcasm off.

If you look @ foto 1 & 2, the portion of the adjusting screw that contacts the band ear ragged. The material is quite soft doesn't slide easily on the band ear.

On my late model tranny, I smoothed up the O D, then using the parting tool made the face smooth. I then took a thick washer ( 7/16 I D diam I think) about 1/16" in thickness. I then turned the diameter of the pin to that of the I D of the washer. Then I ground the O D to just smaller than the I D of the threads in the tranny cover. I Don't remember how I did the final assembly, but remember that I chose to some how thread the screw in till I could slip the washer on then finish the adjustments.

Please check the present pin diameter to verify my memory.

Your Mileage may vary.

On my memory, I've still have it, but someone stole the card file

Sincerely

Jim Weir


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dana A. Crosby in Glendale, Az on Thursday, January 29, 2015 - 03:10 pm:

With my tongue firmly inserted in my cheek, Your problem is lack of lubrication. You are woefully short of dirt, grease, and oil. That said...parts and positions look right to me.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Thursday, January 29, 2015 - 04:11 pm:

A cracked low drum could also cause the problem. As you adjust the band tighter, the drum cuts the lining and causes the pedal to go closer to the floor. However, you say there is no lint in the screen, so that might not be the cause. I am thinking the problem is in the shaft, cam, or notch. One other thing that might help would be to put one or two washers on the end of the shaft on the pedal side of the band ear. That would adjust the band closer to the drum on the pedal side. Then back off the adjustment screw a turn or so. Then when you push the pedal it would not go over the center. Worth a try.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem - SE Michigan on Thursday, January 29, 2015 - 04:19 pm:

Paul,

It looks like you're using wooden band lining? You still definitely need some neutral in your band adjustment but it's not as critical as with Kevlar linings. Don't afraid to take up the band a bit more, especially at first, since the linings probably aren't fully seated yet and frequent adjustment may be needed until they settle in.

Are you using a new pedal shaft cam?

Try actuating the pedal by hand, with the motor turned off and the trans cover off. As you slowly actuate it, carefully observe what you feel and what you see. Look for anything that appears/feels stiff or binding.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary London, Camarillo, CA on Thursday, January 29, 2015 - 05:00 pm:

Two things come to mind. One is the mating of the pedal cam. From the pictures some of yours look worn and that can cause trouble with the pedal movement and how well it actuates the band. The other is with the wood bands. I run them and like them. Somewhere I read to add some ATF to help smooth out rough operation. I don't recall where I heard it, but every once in awhile I add 1/2 quart of ATF when the oil is low and it seems to make a difference. Another thing that I think may cause rough shifting is if the bosses on the inside of the brake drum are too rough for good clutch operation, but I'd want to hear from others that really know trannies on that.
I did have bad cams a number of years ago; changing them made a big difference.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul O'Neil, Fullerton, CA, USA on Thursday, January 29, 2015 - 07:50 pm:

I'm just a bit cornfused about some of this. First, are the pins Nathan mentioned the ones shown in the circles numbered 1 & 2? Next, where is the cam on the low speed band? Is it inside or part of the linkage outside?

The adjusting screw is the part that extend outside on the right side? Is the rough part inside next to the band ears?

Yes, the bands are wood. I thought it best to start with wood as my T driving skills are developing. I poured some ATF on the bands when they were new but not in any of the subsequent oil changes. Because this motor is so new, I had the bands VERY loose. Now that I am driving the car and have a better feel for it, I have been tightening the bands bit by bit. Now I can HEAR when they start to engage the drum. I'll give the low speed band another 1/2 a turn to see if it helps. Now that I have more practice I may not need as much neutral as I did at first.

I'm not sure about the pedal shaft cam. I know that Larry Blair had to take the pedals all out to machine the hogshead and he did have to replace one of the shafts that was worn or bent. I'll have to check the bill to see which one.

BTW, I thought this motor had become quite a pig pen. It has been driven possibly something like 500 miles (just a guess) since it was put together and there are little seeps in several places.

Vintage Paul


Top of pagePrevious messageNext messageBottom of page Link to this message  By Nathan Fahrni on Thursday, January 29, 2015 - 08:25 pm:

Paul,
the pin I had mentioned was number 1. Four or so years ago when we had the engine out of Dad's car the replacement pins were being made out of too soft of material. The "cam" that I refer to is the part that is pinned onto the pedal shaft with pin #1. The adjusting screw is the threaded part that sticks out the right side with the two flats milled on it. The rough part that Jim refers to is at the top edge of the circle marked for pin #2 where the band ear rests against. Another thing I noticed, and it could just be the picture or my eyes, it looks like the cotter pin at location #3 on the clevis is missing. That would allow the clevis to "walk" in and out of the loop on the bottom of the low pedal making it bind up. Hope this helps. I would probably put the washer on the other side of the pedal loop and then cotter pin. Oh, another thing I experienced once... If the cams (whether the part on the pedal shaft or bolted inside the hogshead) were wore and welded up they could be mis-shapen causing binding. Hope this helps. -Nathan


Top of pagePrevious messageNext messageBottom of page Link to this message  By Peter Kable - Kiama NSW OZ on Thursday, January 29, 2015 - 10:25 pm:

Paul,

Can you tell us how far the low pedal moves side ways to the right when you push the pedal down,
The cam is inside the gear box and pressing the pedal moves it to the right clamping the drum.

The pedal side ways movement should be about 1/2" if in good condition, if the cam is worn it does not move sideways enough to clamp the drum tightly.

As the pedal moves sideways check also that the pedal is not rubbing on the side of the slot in the floorboards when you press it down. If that's the problem its not obvious if you are working on the transmission with the boards out of the car.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Treace, North FL on Thursday, January 29, 2015 - 11:11 pm:

Paul

That washer you show in Pic #3 should not be there. Have hunch that is causing the sticking, as the pedal pushes out and now that loose washer will find its way to impinge on the Bendix cover.

Remove that washer, not needed and may be the issue.

For ease of getting the low pedal feel right, go back and start again with setting for 'free neutral'. Follow the steps in the Service Manual.

Remove floor boards as you test drive short distance.

Remove the clevis hook up from the low pedal to the lever.

Keep the lever straight up so you have neutral and no rear brakes are engaged.

Now start and run the T with only the low pedal. Push in and feel the go. Release and feel the T go back into neutral. Test and test that, turn the adj. screw on the low pedal if needed to get good low action.

This exercise will determine what/why/how to get low pedal to be smooth, that is first thing to do. (Maybe there are issues with cam or rivet loose in low pedal, but that will become more clear the more you just exercise low pedal, watching with the floor boards out.)

My choice is to now check that the clutch adj. screw, the one that is the bolt riding on the clutch lever is set correct for good neutral. With the engine running, and clutch lever up, just where you have kept that lever in that spot when running only in low. Now turn the bolt down, if the T creeps too much, back out the bolt, that is setting for best neutral. Turn the bolt until it gives the best neutral, that is, minimal or no creep with the engine in low idle.

Now with low pedal sorted out, in other words the T runs well in low only. And now you have set the T for a good neutral, you can now reconnect the clevis and complete the setting of 'free neutral'.

Then go to the task of setting for "free neutral", by adjusting the clevis between the low pedal and the clutch lever.


As below steps, start now at paragraph 4, the one that reads "We are now ready....". Now you will re-fit the clevis correctly, remove any washers, and see that the clevis fits well, and adjust as worded in the document. Be sure to push the clutch lever forward now to begin this refitting of the clevis.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul O'Neil, Fullerton, CA, USA on Friday, January 30, 2015 - 08:27 pm:

My Sunday to work on the car just got washed out by the shifting tides so it will be next week before I can check on the things listed here. Thanks to everybody for the help. With so many good suggestions I ought to be able to get things sorted.

I'm still amazed at how many complex procedures are needed to achieve the simplicity of the Flivver.

Vintage Paul


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul O'Neil, Fullerton, CA, USA on Wednesday, February 11, 2015 - 08:08 pm:

I had a bash at fixing this low pedal issue this past Saturday. First was an inspection. The floor boards had been rubbing on the pedal a bit but I couldn't see any interference to movement. The boards are just a bit loose and travel with the vibration of the car.

The inspection cover was removed and the pedal was pressed by hand so I could see what happened, The pin looks solid and I saw no looseness anywhere. Yes, the pedal DID move inboard about 1/2". I could see nothing wrong.

Next the link from the low pedal was removed and all the washers ditched. That turned out to be a tough job as I had installed it with a nice high quality stainless cotter pin that was also very stiff. It proved to be VERY difficult to remove and I ended up having to recruit an assistant. I'm just too old and fat to fit in easily in that area of the car.

Does anybody still sell the soft easy to bend cotter pins? I would like to go back to them.

While the link was off I took a stricter interpretation of the 1/16" free play and extended the clevis a turn and a half to make the linkage more responsive to the pedal.

While the link was off I adjusted the low band another 1/2 turn tighter and ran the motor without the floorboards so the motion of the pedal could be watched. I saw nothing wrong but the fact that low now engaged with very little pedal movement. After slackening the low band the 1/2 turn I tried it again. The band now tightened where I think it should and I could feel no stiffness or over center issues. The adjusted link was reinstalled.

I wasn't sure what to do with the lever so I did nothing. Since the new large drum axle was installed with fresh linings the lever never goes further rearward than vertical and I was it was getting a good free neutral so I left it be as it is.

It was time for a test drive with no hood or floorboards to try to see & hear what was going on. The first thing I noticed was that I now have more room between low pedal engagement and high engagement, a good thing as that was a primary complaint. It also seemed that the stiffness/over center issue was reduced or gone but this was not certain.

I was surprised at just how loud the intake hiss is. You can really hear it when the power is on.

The test drive was short as I did not care to have my size 14 EEEEs trompling on wiring and linkages. The next day I went on a longer drive with floorboards & hood, perhaps an hour or so and at first I thought the issues were gone. After the car became thoroughly warm the stiffness in the low pedal returned but at a higher position in the arc of pedal travel. That allowed a better feel for the tightening of the band and eased the driving chore somewhat.

I'm going to try taking the car on its first club tour this Saturday and I hope to have a clearer picture of the issue with extended seat time and possibly consultation with other T folk.

For those of you who thought the motor too clean to operate well I can say that the motorcycle chain lube that was sprayed on every moving part got everywhere and I was only partly successful at cleaning it up. The Santa Ana winds out there now and the next drive ought to add plenty of vital dust, grime and general filth, enough to please even the sticklers.

Vintage Paul

Here are some pics of linkage as it is now:





Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Treace, North FL on Thursday, February 12, 2015 - 08:50 am:

Paul

Nice description, and seems that you got it right now. That's what it takes, inspection, adjustment, test, and re-inspect.

As for the washers still in place, IMO, remove them. Ford never had washers on clevis pins.

The clevis pins need a little slop, they have to wiggle some. There is lateral movement to the lever and clutch arm, so that 'wiggle' will allow the clevis parts to 'self-align' without sticking, galling, or hanging up when the parts move.

And, like you added, that oil is good! Oil on the inside and outside of a T is meant to be.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Thursday, February 12, 2015 - 08:56 am:

Glad you have the problem nearly licked. Your cam bolt is pretty close to slipping off the side of the cam, can you carefully bend the cam over so that the bolt rides over closer to the center of the cam?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Thursday, February 12, 2015 - 08:59 am:

I do have a little overcenter feeling in the pedal when starting in low - that's when the drum actually stops and the self actuating of the low band forces the left ear a little more to the right and the pedal goes a little further down without any additional foot pressure. Not actual overcenter - the pedal releases by itself without wanting to stay down, it's just a phenomena I've attributed to the self actuating properties of the band.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul O'Neil, Fullerton, CA, USA on Friday, February 13, 2015 - 01:23 pm:

I'm far from sure that the problem is solved. I'm still new to T driving & I spend a lot of mental energy operating the Flivver & trying not to get run over or hit anybody which means I am often not paying attention to secondary issues like the operation of the pedal. Tomorrow will be my first club tour and I hope to be able to find out just where things are.

The washers are oil retention washers. I put them in to try to hold oil in the joints and it really does seem to work. I will remove any that might interfere with movement.

How could the cam be bent? If it was just bent over somehow, wouldn't it meet the bolt at an angle? When I put this car together the bolt actually slipped completely off the cam so I reversed it and while it looks awful, at least it stays put. When the bolt was off I ground the head into a smooth dome shape to try to get it to slide more easily over the surface of the cam.

Why is this misaligned anyway? What would be a proper fix?

Vintage Paul


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Treace, North FL on Friday, February 13, 2015 - 03:55 pm:

Paul

Anything could have happened to the clutch lever, or the cam on the cross shaft. Those two parts are aligned by easy way, bending to adjust. Not hard to do.

For the clutch shaft, put a big wrench up close to the hogshead on the shaft so it won't bend there. Then put a monkey wrench on the arm and twist it to align.

Both of these parts could have been bent over the years, the clutch lever because it sticks out, if the engine was pulled, and then placed on the floor, rolled on it side, the heavy weight can bend that little lever arm!



So cannot think of why this owner did this fix! Bent a sheet metal sleeve to keep the lever over the cam. All was needed is a little bending to align!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul O'Neil, Fullerton, CA, USA on Monday, February 16, 2015 - 04:40 pm:

Thanks Dan, that will be worth taking a look at. Even though the lever seems to work OK now, the contact portion looks bad and it may slide easier with proper adjustment. I'll see if I can figure out how to do this without bending the shaft or the other side of the arm which seems to be lined up pretty well.

Vintage Paul


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul O'Neil, Fullerton, CA, USA on Monday, February 16, 2015 - 04:50 pm:

I spent a lot of time in the car Saturday and wound up somewhat confused about what is going on with the low pedal. First, it seems that there is no issue until the car has been warmed up and driven some distance. Once the car IS warmed up and has some miles on it, SOMETIMES the pedal seems to get stiffer as it approaches engagement of the low band. Other times all is well and there is no problem at all.

The darned thing is "sometimey."

I drove the car a lot of miles in some challenging traffic and never stalled it even though not all of the starts were as smooth as they might have been. I think that on the next work session I'll see about adjusting the clutch arm and just see what happens. Possibly something will happen to make all clear . . .

Vintage Paul


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Tuesday, February 17, 2015 - 04:49 pm:

When the car is warmed up, does the pedal go farther down or not as far as when cold when you push it? If it goes farther down, it is probably the band expanding with heat. This might or might not be normal.

Try putting the car in neutral on a level surface. The car should not creep with the engine running. Note, it might creep a little when cold due to thick oil, but in any case, not when warm.

Now turn off the engine still in neutral. Get out and push the car. The engine should not turn when you push in neutral, and then go in front and turn the crank. The car should not move forward nor backward then the crank is turned.

After doing the above, try adjusting the low adjustment inward about 1/2 turn. The pedal should now get tight with the low between 1 inch and 1 1/2 inch from the floor. Repeat the tests in neutral. The car should not move when cranked nor the engine turn when you push the car.

Try driving the car and see if the pedal still feels like it is going "over center"

Here is another thing which is sometimes necessary. Depending on the thickness of the band material. When you get the low band adjusted to about 1 1/2" above floorboard, check the band ears. With the pedal out, if the right side of the band is tight against the drum but the left side is loose, you will need to add one or more washers between the notch on the shaft and the left ear. That will allow you to back off the adjustment. Then both ends of the band will be loose when the pedal is out. When you install those washers, be sure they don't fall into the transmission.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem - SE Michigan on Wednesday, February 18, 2015 - 03:58 pm:

Paul,

Maybe the best thing to do is nothing. As long as it's just a nuisance and can't possibly affect your safety, I would just drive it that way. The thought being, everything is new & tight. If you give it a chance, whatever is binding may "break in" and just go away. Conversely, if it gets progressively worse, the trouble may be easier to spot.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul O'Neil, Fullerton, CA, USA on Wednesday, February 18, 2015 - 08:33 pm:

On the next work session, possibly this coming Sunday, I'll see about bending the clutch lever so that it rides on the cam better. I'll also check for good neutral both by running the motor & by pushing the car as Norman suggests.

After that, I probably ought to do as Jerry suggests and just get more time on the car.

I no longer think of the problem as being "overcenter" but as a stiffness.

The fact that I can't form the words to accurately describe the issue as it is NOW leads me to think it needs more time to sort itself out and for me to get a feel for what is going on.

Vintage Paul


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