Clutch pedal limit stop

[DeepBusch69]

I was wanting to add a stop or limit for the clutch pedal so I don't push it too far a damage it.  I have some standard CNC pedals.  Any good ideas out there, thanks

 

[Richard h]

Take the upper bolt for the cylinder out and  get one long enough to double nut to hold cylinder and use the head as a stop for the pedal. One I did on a Busa car.

 

[Fullthrottleguy]

Of course I can never find the pIc..

But I make these all the time 

I put a small flat bracket on the top bolt -I notch the bottom so it slides over the shaft and make it  wide enough so it cannot rock  I think 2" 3.16 plate - drill a hole in the bracket and put a furniture adjustable foot - I get from Ace for $10  you can search adjustable leveling feet  to find them on amazon or ebay- this way you have some cushion and you also have the stop at an angle that hits the flat of the pedal arm, it won't scratch the arm  and does not put excessive pressure on the pedal arm like you have if you make the stop to low - kinda like this 

 

[Doonit]

Never thought this was an issue. won’t pressing the pedal “too far” just compress the spring and piston then stop?  What damage can be caused? Xtra pressure on the piston or the housing? Just curious. 

 

[J Alper]

Never thought this was an issue. won’t pressing the pedal “too far” just compress the spring and piston then stop?  What damage can be caused? Xtra pressure on the piston or the housing? Just curious. 

Depends on the master cylinder but it can bend the fingers on the pressure plate 

 

[J Alper]

I was wanting to add a stop or limit for the clutch pedal so I don't push it too far a damage it.  I have some standard CNC pedals.  Any good ideas out there, thanks

View attachment 11546

It also depends on the master cylinder, if you have a 3/4 with a 8'' clutch and the pressure ring on the 8'' pressure plate, this could happen,   does not really happen on a 8'' clutch with a 3/4

Also 

You can run a 5/8 master cylinder, this will make it super easy to push in the clutch and will never over extend the pressure plate, this gives it a nice feel and will not have maximum throw in the pressure plate, 

 

[Richard h]

Never thought this was an issue. won’t pressing the pedal “too far” just compress the spring and piston then stop?  What damage can be caused? Xtra pressure on the piston or the housing? Just curious. 

Me either, except on a busa, bike  motor, they will shove the clutch rod through the engine case if not careful.

 

[Okie]

Budlight, you will laugh at mine, if you haven't noticed it before. It was an emergency fix at the dunes. I need one because I still use the old cnc pedals with a stock Subaru slave cylinder, on a Subaru trans. It worked, so I just left it.

 

[Fullthrottleguy]

As J Alper said you can overthrow the clutch and it’s possible depending on what clutch plate you have that you can actually blow the seal in the slave cylinder or you can make the clutch stay in and it won’t come back out so you’ll just won’t have any clutch you’ll just basically be in neutral

I’ve seen some of the non-KEP units do that and when you take them apart the clutch spring is literally broken inside

So the pedal stops always a good idea but like some guys have said you can run a master cylinder that has a longer throw like a smaller one like a five eights and as long as you don’t have a dual disc clutch you won’t have any problem with release and you can put it all the way to the floor it’s just that usually you won’t have as much FreePlay in the clutch that way

It makes a little hard on the throw out/release bearing

 

[Doonit]

Why I asked… thanx @J Alper and @Fullthrottleguy always learning on this site. 

 

[onanysunday]

Here is mine. I built one since Bill at AZ transaxle said the TO bearing in an S4 can over travel. I keep mine set at 1/4" like in this video. Every now and then I adjust a thread or two as the clutch wears.

 

[Kevin]

dont have a clutch in my car, but i did make one for my brake pedal, its welded to chassis and stops the pedal. i made it so it stops at the point i have no leg left to push the pedal any farther and have the master linkage set so the full travel of the master is utilized in the pedal travel i have set for my foot.

 

[Fullthrottleguy]

dont have a clutch in my car, but i did make one for my brake pedal, its welded to chassis and stops the pedal. i made it so it stops at the point i have no leg left to push the pedal any farther and have the master linkage set so the full travel of the master is utilized in the pedal travel i have set for my foot.

View attachment 11679

Nice way to do it on swing pedals, maybe put a rubber pad on the stop - its nice

 

[Kevin]

Nice way to do it on swing pedals, maybe put a rubber pad on the stop - its nice

so far its never come close to hitting the stop thankfully. if it does hit the stop then i got problems! lol

 

[TGSRacing]

Mine is very similar to what others have posted for the CNC pedals, I also agree on the important reasons of doing it to potentially save the clutch components however, a byproduct at least for me has been its easier to drive. Now I dont have to think about how far I push the clutch if I am rowing through the gears or need to stop quick due to an edge or something I just lay into it with my left foot and let it hit the stop without thinking. For that reason I wish I had done it sooner.

 

[Rockwood]

so far its never come close to hitting the stop thankfully. if it does hit the stop then i got problems! lol

 

[SeanRitchie]

Two things can happen without a pedal stop: 

1. Over extend throw out bearing into pressure plate fingers, which can pull the bearing off the fork in a typical VW style release shaft/fork mechanism, or push the piston out of the housing on an Albins/Weddle HV and new design S4D/S5D Chevy bell housing with hydraulic slave cylinders built inside the bell housing. Either issue requires pulling the engine to fix.

2. On Weddle/Centerforce clutches, throw bearings can interfere with centrifugal weights on pressure plate, pulling the bearing off the forks. Or over extend the fingers into the clutch discs behind and interfere with drive pins on discs. 

 

[Fullthrottleguy]

Two things can happen without a pedal stop: 

1. Over extend throw out bearing into pressure plate fingers, which can pull the bearing off the fork in a typical VW style release shaft/fork mechanism, or push the piston out of the housing on an Albins/Weddle HV and new design S4D/S5D Chevy bell housing with hydraulic slave cylinders built inside the bell housing. Either issue requires pulling the engine to fix.

2. On Weddle/Centerforce clutches, throw bearings can interfere with centrifugal weights on pressure plate, pulling the bearing off the forks. Or over extend the fingers into the clutch discs behind and interfere with drive pins on discs. 

I fixed alot of Centerforce's on a number hot street cars  when people would over center the clutch spring at really high RPM like an 8000 RPM shift,  the spring would be on the other side so the "cone" would actually hold the clutch depressed and it would not engage unless you let off the throttle and RPM came way down. A simple clutch stop and problem solved. 

The Weddle/Centerforce weights really increase holding power for free imo- no added pedal pressure - the over centering and hold the clutch "open" convinced me maybe for the wrong reason, but it showed the force was there.   I am not sure with the Weddle flatter weight design that can happen, but on their BBC clutches I guess its fairly common if you set them up wrong. The answer is always proper setup (flywheel to clutch plate air gap) and a pedal stop for me ...

 

[Cable Guy]

Question: I have a S4S with a Kennedy dual disc clutch. Recently I have been having issues with clutch arm on tranny returning all the way. I can push the clutch pedal in 3 or 4 times than nothing. Go back to Trans and there is a ton of slack on my slave and the clutch arm is half depressed. I can push arm back with my hand but I hear a clunk inside. I take it I’m pulling motor to see if I damaged throughout or pressure plate?