pictures of pedal assemblies 340 vs. others
- Thread starter Oldmanmopar
- Start date
-
daliant
Befuddled
Its the measurement from the pedal pivot to the push rod pin that really matters, the distance from the assist spring pin the push rod pin really doesn't matter unless your trying to identify a pedal setup from a 340 car. Obviously the greater the distance between the pedal pivot and the push rod pin the more travel you'll get at the push rod, this also increases effort thus the need for the heavier assist spring to keep people from whining about too heavy of a clutch. Also it seems like some cheap part store 3 finger pressure plates dont have the finger hight adjusted right, this will cause disengagement problems and clutch chatter.
1wild&crazyguy
Banned
well if you need the 6'' pivot spread, somethings wrong.
my 5 1/4 spread works fine.
my 5 1/4 spread works fine.
1wild&crazyguy
Banned
Right, cool.
it's the 5 1/4 vs 6'' that I laugh at.
my 5 1/4 spread works great and has no clutching issues, so I doubt the shifting issues the mag reports.
Im done on this, thats all I wanted to confirm, for that was my point.
abodyjoe
Well-Known Member
**** i'll have to see what the heck i put in my car. whats the extra brace look like?
M any drivers of four-seed A-body cars have complained over the years that they have difficulty shifting gears during hard-acceleration situation. I am here to you that the main source of the problem may not be the driver, its the clutch pedal. When four speed A-bodies first hit the dealers, the clutch ratio was greater than that of the laterA-bodies. The reason for this is thatChrysler eventually shortened the ratio of the pedal so that the little lady with the six cylinder car would have a softer pedal to push down. Our '68 Hemi four speed cars had a very good ratio on the pedal and did not have this shifting problem.
Stock pedals on most A-body cars have a measurement of 5 1/4 inches from pin to pin. Pin to pin refers to the two pins on the pedal. One pin connects the pedal to the torque shaft arm, and the other pin is for the over-center spring. In order to improve shifting of your A-body, all you need to do is cut and extend the arm at the rear of the pedal (the arm connected to the torque shaft connecting arm). If you increase the pin-to-pin length to six inches, the ratio of your clutch pedal is increased, thereby allowing more clutch separation when the pedal is depressed. Usually, more is better, but in this instance, extending the arm more than six inches will cause an over-extension of the clutch fingers and cause binding and/or damage to the clutch assembly.
To begin, you'll need to remove your pedal over-center spring, if its installed, and the clutch pedal. To first remove the spring, have someone depress the clutch pedal while you insert washers into the spring so that they "pinch" between the spring's coils when the pedal is released. Once you have the washers inserted release the pedal, the spring should come out with little persuasion. Once the spring is removed, you can next remove the clutch pedal. The clutch pedal rides on a shaft that pivots inside the brake-pedal pivot. To remove the clutch pedal, you need to remove the e-clip that holds the pedal from falling out, and the rod going from the clutch pedal to the torque shaft.The e-clip is located on the throttle-pedal side of the brake pedal pivot. Remove the e-clip and the pedal slides out. Be sure not to lose the nylon/plastic bushings that are on the clutch's pivot shaft, and ride between the clutch pivot rod, and the brake-pedal pivot. The bushings slide off the clutch pivot arm.
Now that you have the pedal out ot the car, you can increase the ratio. You will need to cut the arm that the touque-shaft connecting rod connects to. Make sure when you cut and weld the arm back in place you keep every thing aligned as it was when you removed it. If you weld the arm back together and the pin for the clutch rod is not straight, you will not be able to reconnect the pedal to the torque shaft rod. After you cut the arm, you'll need to weld an extension piece into place. Don't skimp here and use lesser thickness steel. This area receives alot of pressure when the clutch is applied, so make sure you weld it back together with a good weld an the proper thickness of metal.
Once you have the pedal modified,just put it back in the car. Now, if you are not shifting your A-body's four-speed at high rpm, this modification may not be worth your while, but for you guys that like to wind your engine tight and then shift. you'll notice a big difference in high rpm shifting.
What this modification does is give you more pressure-plate and clutch-disc departure from the flywheel. The more plate departure that you have , the easier the transmission will shift. This modification will work whether you have a three finger clutch or a diaphragm clutch. The only difference is that when a diaphragm clutch your pedal may sometimes stay on the floor if you have the over-center spring in place . I wouldn't recommend using a Borg and Beck or long style clutch without the over-center spring.
CAPTIONS
1. As you can see in the pics, the car we're working on does not have the over-center spring. this is because it has a diaphragm style clutch. To remove the pedal, unhook the torque shaft and take the e-clip off. You should now be able to slide the clutch pedal out.
2. Once the pedal is out, you can see where the measurements are taken. Our pedal is the shorter 5 1/4 inches pin to pin
3. We used a band saw to cut the pedal, but a hack saw will work. Just be sure to cut the right extension and not the one with the over- spring pin center.
Stock pedals on most A-body cars have a measurement of 5 1/4 inches from pin to pin. Pin to pin refers to the two pins on the pedal. One pin connects the pedal to the torque shaft arm, and the other pin is for the over-center spring. In order to improve shifting of your A-body, all you need to do is cut and extend the arm at the rear of the pedal (the arm connected to the torque shaft connecting arm). If you increase the pin-to-pin length to six inches, the ratio of your clutch pedal is increased, thereby allowing more clutch separation when the pedal is depressed. Usually, more is better, but in this instance, extending the arm more than six inches will cause an over-extension of the clutch fingers and cause binding and/or damage to the clutch assembly.
To begin, you'll need to remove your pedal over-center spring, if its installed, and the clutch pedal. To first remove the spring, have someone depress the clutch pedal while you insert washers into the spring so that they "pinch" between the spring's coils when the pedal is released. Once you have the washers inserted release the pedal, the spring should come out with little persuasion. Once the spring is removed, you can next remove the clutch pedal. The clutch pedal rides on a shaft that pivots inside the brake-pedal pivot. To remove the clutch pedal, you need to remove the e-clip that holds the pedal from falling out, and the rod going from the clutch pedal to the torque shaft.The e-clip is located on the throttle-pedal side of the brake pedal pivot. Remove the e-clip and the pedal slides out. Be sure not to lose the nylon/plastic bushings that are on the clutch's pivot shaft, and ride between the clutch pivot rod, and the brake-pedal pivot. The bushings slide off the clutch pivot arm.
Now that you have the pedal out ot the car, you can increase the ratio. You will need to cut the arm that the touque-shaft connecting rod connects to. Make sure when you cut and weld the arm back in place you keep every thing aligned as it was when you removed it. If you weld the arm back together and the pin for the clutch rod is not straight, you will not be able to reconnect the pedal to the torque shaft rod. After you cut the arm, you'll need to weld an extension piece into place. Don't skimp here and use lesser thickness steel. This area receives alot of pressure when the clutch is applied, so make sure you weld it back together with a good weld an the proper thickness of metal.
Once you have the pedal modified,just put it back in the car. Now, if you are not shifting your A-body's four-speed at high rpm, this modification may not be worth your while, but for you guys that like to wind your engine tight and then shift. you'll notice a big difference in high rpm shifting.
What this modification does is give you more pressure-plate and clutch-disc departure from the flywheel. The more plate departure that you have , the easier the transmission will shift. This modification will work whether you have a three finger clutch or a diaphragm clutch. The only difference is that when a diaphragm clutch your pedal may sometimes stay on the floor if you have the over-center spring in place . I wouldn't recommend using a Borg and Beck or long style clutch without the over-center spring.
CAPTIONS
1. As you can see in the pics, the car we're working on does not have the over-center spring. this is because it has a diaphragm style clutch. To remove the pedal, unhook the torque shaft and take the e-clip off. You should now be able to slide the clutch pedal out.
2. Once the pedal is out, you can see where the measurements are taken. Our pedal is the shorter 5 1/4 inches pin to pin
3. We used a band saw to cut the pedal, but a hack saw will work. Just be sure to cut the right extension and not the one with the over- spring pin center.
l. If yours works so well than whats the worry.There are some having problems with geometry mismatching parts making 4spd cars.This artical is all about making it easier to shift at high rpms. But if your motor don't go up there you have nothing to worry about. And if you can shift it with a 5 1/4 throw at over 7000 , you are the man. I personally twist the livin **** out of everything I own. And it works for me. I also noticed its alot easier going in gear , also down shifting and reverse. It works for me. And I don't think Herb McCandless would would say it , if it wasn't true.
1wild&crazyguy
Banned
I agree, and I'll be trying this mod at some point.
From what I got out of the guy that I purchased the 4 speed conversion parts said it came out of a '72 Duster 3 speed on the floor. The small block biscuit k-frame that I also got from the guy supposedly came out of the same car. It has the washer welded to the front. So my guess (I never actually saw the car sense he towed it back to the scrap yard
) is that it came out of a Red (floor hump was red), '72 Duster 340, 3 speed on the floor. Also I believe it has the 6 inch spacing too.
This needs revisiting, has anyone tried this on the early A-bodies, I think this may solve some of the problems I am encountering. Trouble going into gear and possible throw out bearing failure. When I installed all of my linkage, I alway felt I could use more geometry in my linkage/pedal set up. I also think the pedal design for the early A-bodies is slightly different then the late model A-bodies. There seems to be a more pronouced step in the bar the pedals is attached too. I will snap a pic this weekend an post it to see if anyone else see what I am seeing.
Just had a pm from" Dart star" He did the mod and said it corrected his problem and thanked me for the thread. Also had others tell me they no longer clunk going into reverse after the mod., and now theirs shift like butter. No more missing gears. So I guess you learn something everyday. Not everyone knows everything including me. But I would Trust Mr. Mopar "Herb McCandless". Why would he say it if it wasn't true. Those who never heard of him don't have a clue.
damnimcooltom
Too Cool For School
I have these pedals, and the pin-to-pin distance is 5 11/16". Can that the right? Are they even A Body pedals?
1wild&crazyguy
Banned
Dont believe everything you read...
..and dont beat horses when they're already dead.
..and dont beat horses when they're already dead.
abodyjoe
Well-Known Member
ok what is that welded bracket all about?? is that original? only reasonm i ask is because the pedal set up i put in my dart has the same thing. i just thought someone tried to stiffen things up over the years...
1wild&crazyguy
Banned
Exactly, Im not...it's you that is still concerned, you bring it up again and quote me again.
Thanks but I dont really care about this stuff cause it's not an issue with my cars.
peace.
Yep thats factory. All clutch pedals (at least A-bodies) have that. Auto pedals don't.
scottmd
Well-Known Member
Notice in the DC manuals under 4 spd section they suggest adding 3/4'"to the z bar arm across the board with no mention of what pivot distance your pedals have 5.25" or 6' ......
rickstershemi
It's True....I'm Nutz
- Joined
- Jun 2, 2010
- Messages
- 320
- Reaction score
- 4
Have that conversation with Herb McCandless....the man has forgotten more about four speeds than everyone who has posted on this thread added together....lol I have that issue of Mopar Muscle and have already lengthened mine on the 64 Valiant....Thanks Herb :glasses7:
Rickster
I have a somewhat related question....
I am putting together a 4 speed pedal assembly from a box of parts. How is this sub-assembly supposed to behave when not installed in the car? Specifically, what I'm talking about is the function of the over-center spring. I thought that as I would move the clutch pedal down and up, that the spring would try to bias the pedal into either of these end locations. What I'm finding is that the spring wants to pull the pedal down, and if I pull the pedal up it is extremly unstable like a mouse trap (and a hell of a lot more dangerous!). Also, the spring pulls the pedal down such that it's bending the start depression switch bracket.
Have I done something totally stupid, or overlooked something simple? Any help would be appreciated. Thanks.
I am putting together a 4 speed pedal assembly from a box of parts. How is this sub-assembly supposed to behave when not installed in the car? Specifically, what I'm talking about is the function of the over-center spring. I thought that as I would move the clutch pedal down and up, that the spring would try to bias the pedal into either of these end locations. What I'm finding is that the spring wants to pull the pedal down, and if I pull the pedal up it is extremly unstable like a mouse trap (and a hell of a lot more dangerous!). Also, the spring pulls the pedal down such that it's bending the start depression switch bracket.
Have I done something totally stupid, or overlooked something simple? Any help would be appreciated. Thanks.
74Dusted
Stock Piler of 340's
My '74 was like that when I bought it, The pedal was jammed against the floor and the spring wouldn't let it move. I had to cut the spring in half to remove the pedals from the car, that's how tightly wedged to the floorboard the clutch pedal was :wack:
My '74 had a later style Pedal Assembly in it when I bought it. (wasn't original though, since it was originally a 318 / 904 car.)
I yanked it out (and cut the spring in the removal process) and tossed it on the shelf. Now I'm getting ready to swap a 4-Speed in it, and My later style pedals measure 6" pin to pin spread (no brace unlike the 340 pedals in oldmanmopar's pics)
What's the deal with that? Did somebody install earlier pedals in a later "cradle" / Mounting Bracket? What's to keep my pedal from jamming against the floor again (with the spring installed) when I convert to 4-Speed. My options at this point are to buy a new spring from Brewers, or forget about the spring and go with a Diaphragm Clutch? Right?
If you get in any car without the clutch linkage hooked up and just move the pedal downward alittle bit the pedal will be forced to the floor hard. This is to help depress the clutch pedal when it is hooked up.
It is a helper spring. But when the pedal is pulled out it will hold it out just for about one inch of travel. This is to keep pressure off of the throw out bearing when not in use.
One of the recomended things to do is remove the spring when installing a diaphram pressure plate. This is correct you don't need this spring for help on a diaphram style. They are easy to depress.
But on a street car you will want to replace this removed spring with some type of lighter spring for its other purpose. That is to hold the pedal up. If you allow your pedal weight to ride on the linkage it keeps pressure on the throw out bearing. This causes the bearing to spin contantly which will cause it to wear out alot faster then normal. The bearing should only be in contact with the fingers when the pedal is in use.
For the person who cut the spring. If you put your hand under the pedal non any mopar and then give it a push without the linkage hooked up it will probably crush your hand. That is how hard that spring pulls down. If it doesn't stay at the top for the first inch. it is probably bent like the one pictured above.
For bending the start bracket. Once it is installed in the car the floor will be its stop not the bracket.
Hope this helps some . any question feel free to ask. Steve
It is a helper spring. But when the pedal is pulled out it will hold it out just for about one inch of travel. This is to keep pressure off of the throw out bearing when not in use.
One of the recomended things to do is remove the spring when installing a diaphram pressure plate. This is correct you don't need this spring for help on a diaphram style. They are easy to depress.
But on a street car you will want to replace this removed spring with some type of lighter spring for its other purpose. That is to hold the pedal up. If you allow your pedal weight to ride on the linkage it keeps pressure on the throw out bearing. This causes the bearing to spin contantly which will cause it to wear out alot faster then normal. The bearing should only be in contact with the fingers when the pedal is in use.
For the person who cut the spring. If you put your hand under the pedal non any mopar and then give it a push without the linkage hooked up it will probably crush your hand. That is how hard that spring pulls down. If it doesn't stay at the top for the first inch. it is probably bent like the one pictured above.
For bending the start bracket. Once it is installed in the car the floor will be its stop not the bracket.
Hope this helps some . any question feel free to ask. Steve
Thank you, Steve.
"If it doesn't stay at the top for the first inch. it is probably bent like the one pictured above." - What exactly is bent (besides the start switch bracket) in my assembly? Can you see the problem in the picture I posted?
I don't think going springless is an option for me, as the clutch I have is a Ram HDX Clutch Set, which states in the instructions that "... pedal effort WILL be heavier..."
"If it doesn't stay at the top for the first inch. it is probably bent like the one pictured above." - What exactly is bent (besides the start switch bracket) in my assembly? Can you see the problem in the picture I posted?
I don't think going springless is an option for me, as the clutch I have is a Ram HDX Clutch Set, which states in the instructions that "... pedal effort WILL be heavier..."
cjh
Well-Known Member
I removed the helper spring in my set-up, as it doesn't let the clutch do it's thing quickly.....in other words, the clutch can slip too much.
This is a RHD arrangement.
This is a RHD arrangement.
-
