How To: Clutch Pedal Adjustment
 

Didn't see this how to anywhere so I'll post it up... I didn't write this, but I did have to insert all the pictures for it. Hope this helps anyone wanting to do this and hopefully I didn't overlook some thread that had all this.

Author: Super Car Tastes - Skoda Budget

Okay, took me a while but I got it together. As mentioned earlier I did the clutch adjustment today. It’s a huge improvement, and I made sure there wouldn’t be any issues with insufficient disengagement or re-engagement of the clutch. Also, I formulated a theory as to what’s causing the problems.

Make sure you fully read the instructions and study the pictures and diagrams to ensure you fully understand the process before starting.

Please note: I put these directions together based on my personal experiences. I am not a mechanic and do not have any professional certification. If you try this, you do so at your own risk and release me from any liability, damage, injury, etc. You assume all responsibility!

Here’s the How To, with some explanations and diagrams to avoid mis-adjusting the clutch:

Tools needed:
12mm crescent (open ended) wrench
Light source (I used a head mounted light to put light where I was looking and keep both hands free)
10mm crescent wrench for clutch cylinder actuator rod (not really needed and actually very difficult to use, but just in case you want to try)
Permanent marker such as Sharpie or Staedtler

Steps:
1. Turn off the engine!! Don’t do this while the car is running!! Obvious but you never know.

2. Move the driver’s seat all the way back to give you room to work.

3. Slide in head first on your back and get under the dashboard. Identify the clutch pedal arm stop bolt. It will look like this:
http://i39.photobucket.com/albums/e1...adjustment.jpg

4. Mark the bolt with a dot or line at one side with the Sharpie. This will give you a reference point. When turning the bolt keep track of how many turns you did and you can easily reverse it back to original.

5. Identify the clutch cylinder piston actuator rod. It’s further up the clutch arm from the stop bolt and looks like this:
http://i39.photobucket.com/albums/e1...odadjust-1.jpg

6. Mark one of the flats on the actuator rod as well. It’s tight in there so do what you can. As long as you can clearly identify your mark you’ll be able to keep track of it’s position. However, it’s not really critical to keep track of it as you’ll see later on.

7. While you’re down there, press the clutch pedal slightly while watching the actuator rod and piston (see diagram above). You should be able to feel and see some free play before the actuator rod actually starts to engage the piston. This is normal and necessary, as this means the clutch cylinder piston is fully released, ensuring the clutch is fully engaged.

8. If you want to keep the amount of free play the same, pay attention to how much it is now, so that you can duplicate it later after making the adjustments.

9. Use the 12mm wrench to loosen off both lock nuts (they’re both 12mm)

10. Push on the clutch pedal to take tension off the stop bolt and you should be able to turn it in. Turn it in (CW) about 2 full turns to start. My final adjustment was about 2.5 turns in. Refer back to the pic of the upper stop bolt.

11. Tighten up the lock nut to set the position of the bolt.

12. Now, check the position of the clutch cylinder actuation rod. You should find that it’s depressing the clutch cylinder piston in partly now. Back off the actuation rod by turning it (screw in towards the pedal). It’s still CW rotation if you’re looking at it from the firewall, but you’ll be upside down looking up from the floor, so experiment.
http://i39.photobucket.com/albums/e1...dadjustmen.jpg

13. Adjust the rod until it’s clear off the piston, and there is a slight bit of freeplay (I set mine up with just a pubic hair of play).

14. Tighten up the locknut with the 12mm wrench. The rod will rotate a bit CW due to friction of the threads but this just increases the free play so it’s okay. Compensate for it by not rotating the actuator rod quite as far as you actually wanted to, so that when you tighten the lock nut it will rotate into the desired position.

15. Eyeball your handiwork, make sure the locknuts are tight, then take it for a drive. This is important – test and adjust, test and adjust. I went through 4 adjustment cycles until I was satisfied the clutch was disengaging and engaging properly while giving the best action. I was learning as I was going so it may only take you 2 or 3 cycles.

16. To test the adjustment. Stop on level ground and fully depress the clutch while in gear. Release the brake and see if there is any sense of the car creeping forward. If so, you’ve adjusted the pedal too far in, so that it’s not pushing the cylinder piston in far enough to fully disengage the clutch. This is not good, and you’ll know because when you change gears you’ll grind the syncros. I’m not sure this is actually possible with the amount of adjustment available, and I didn’t experience it myself because I advanced it cautiously, but you’ve been warned! If this happens, back out that stop bolt a bit!!

17. You shouldn’t have any problems with making sure the clutch is fully engaged if you make sure there is some free play between the actuator rod and the piston. Unfortunately there is no easy test for this, except for maybe clutch slippage under hard acceleration or going uphill. More probably the mis-adjustment will be minor and result in premature failure of the throw out bearing, but you don't want to find out! Again take this as a big warning!

18. Repeat the above steps until you’re satisfied with the feel of the clutch, while ensuring that it fully engages and disengages.

One more time: Make sure you adjust the actuator rod so that there is a bit of free play before engaging the piston to ensure the clutch fully engages!!

Here’s a diagram of the parts in rough relation to each other:
http://i39.photobucket.com/albums/e1...entdiagram.jpg
Note that the actuator rod is above the stop bolt and only connected to the pedal arm (not below and connected to the piston, as shown in a previous diagram – note: it was a valuable diagram and inspired me to do this, so even if it wasn’t quite correct it was still appreciated). BTW, I noticed that I put the fixing point for the spring to the car frame in the wrong spot to try to illustrate the possible spring action. Move it to the left of the pedal arm instead of to the right. Now, try visualizing what the body of the spring will do when the top of the pedal arm moves to the left. The body of the spring will "shift", introducing non-linearities.

Now, to my theory and possible clues to identify differences in clutches. Look at this following picture.
http://i39.photobucket.com/albums/e1...ngandpivot.jpg

I’ve identified the big coil spring that is used to return the clutch pedal. It’s mounted to the top of the arm. The arm pivots below where the spring mounts (see diagram above). Note my spring has white paint on it. Painting springs is a standard way of identifying springs of different strengths.

I believe, from looking at the system, that the big coil spring plays a major role in the spring rate we feel at the clutch pedal. It’s an easy part to change during assembly and it’s possible Mazda did a running production change due to negative feedback.

It would be interesting to get everybody to take a look up at their spring to see what color it is. If there are different colors, then it means that different rates are being used, accounting for the differing experiences. After this has been posted for a while maybe I’ll start a survey to see what color spring everybody has.

Now, here’s my analysis and hypothesis of why the clutch feels the way it did (but not anymore on my car):

After looking at the spring/pedal arm/pivot and pushing on the pedal with my hand while watching the coil spring, I came to the conclusion that due to the way the whole system of spring, spring fixing points on frame and pedal arm interacts, part of the motion is non-linear. This is due to the fact that the body of the spring will actually shift as the clutch arm moves and tries to wind it up. If there was a rod through the body of the spring this would not happen and the spring would be linear and act purely as a torsion spring, but the shifting of the body introduces a hump in the spring tension, making it non-linear in a portion of the clutch pedal’s travel.

I put together three diagrams plotting spring tension vs clutch travel. This is just my guess and is based solely on conjecture. The spring rate curve is pure fabricaton based on my guess at what the spring rate might look like, but I hope it serves to convey what I’m talking about.

The first diagram shows what the stock settings look like. Note that the clutch engagement range is smack dab in the non-linear region of the curve, just where it ramps up quickly and then tapers off just as quickly.
http://i39.photobucket.com/albums/e1...malDiagram.jpg

The second diagrams show what it looks like after doing the adjustments described in the steps above. Note that by moving the pedal arm closer to the firewall it’s pushed the spring into the more linear region of it’s curve, and then readjusting the actuator rod to compensate moves the whole engagement range into the more linear part of the curve.
http://i39.photobucket.com/albums/e1...malDiagram.jpg

The third diagram is the one you must AVOID doing, where the stop bolt is moved in but the actuator rod has not been backed off to compensate. You’ve effectively and permanently set the clutch up as if you were “riding” it, or in other words, resting your foot on the pedal so that it’s partially depressing the pedal resulting in reduced clamping force on the clutch disc. DO NOT DO THIS!!
http://i39.photobucket.com/albums/e1...Adjustment.jpg

Whew, I hope this helps. This took me a while to put together, so apologies for any typos, etc, etc. Again, I’m posting this for informational purposes only, and do not make any claims as to how this may work for you. You accept all responsibility for whatever happens if you try this out.

One of the best driveability mods I've done to my Speed6. Cannot recommend this highly enough.

Thanks I am going to try this setup and as far as different springs / colors I wonder what the speed 3's have since their pedals are so easy.

would i just do these steps the same way for my speed3, because i have been looking in the how to's for the 3 and couldnt find anything like this.

Take a look and see if it all looks the same... I'm sure it's generally the same.

This really helped with making the ms6 easier to drive after getting the new clutch, I recommend doing this no matter what though.

hey so i took a look under my MS3 and it looks different. i know this is going to be on the MS6 post but i couldnt find a post on the how tos for the 3. below i added a video and some pictures to show you guys what mine looks like. they may be hard to understand, if you have any questions please let me know. also the color on my spring is a light blue.

I really want to do this but im scared of fucking it up lol.

this is a must have mod! I remember doing this as my first mod when i bought the car :) memories!!!!! :) but seriously it helps!:biggthumpup:

Just did this mod and it's a big improvement! I was nervous to do it, but once I got under there it really isn't that bad.

Just mark the stop bolt and actuation rod on one side and you're safe. If you screw up you can just back it out to where it was originally.

seems easy enough.

It is :)

Just remember you're adjusting where the pedal operates on the spring. When your done there should always be just a slight touch of free play between the actuator rod and the pedal. Doesn't need to be much, just enough to be sure the pedal releases the rod completely. No leaving pressure on the clutch.....

Anyone know how to adjust this on the MS3?
Edit:
The MS3 is non adjustable.

Does this make it easier to shift without jerking?

Need driver mod. Ms3 not adjustable.

has anyone who has done this notice an increased vibration on their clutch pedal?

Pedal vibes should remain essentially the same.

You're changing the pedal relationship to the spring. Clutch vibes that you see folks discussing are from bent rod(s) transferring the out of balance symptom through the crank and fluid back to the clutch pedal when you've got pressure on the clutch master cylinder.

So, just changing the pedal position should have no effect in that regard.

Thanks, I just did this last night and it made such a difference in driving. My concern for increased vibration was a bust. It was easy to modify and I wish I had done this sooner. Great feel, quicker shifting, overall satisfaction!

Ohhhh my god best thing iv ever done to my MS6. I have the act 6 puck sprung an I just did this on my lunch break and now it feels like a real clutch. lol thank u Thank u Thank u. The post was more than helpful.

Just did this mod and welll...I feel really dumb for not doing it sooner. Super easy thanks to the OP

Hi, I've just done this to my 6 and it worked like a charm!
I've not got much in the way of mechanical knowhow and I managed to do this in 5 mins, while on a tea break.

I can't thank you enough. I was really struggling with the high engagement point and now I'm pulling away like a champ.

I owe you a pint :)

What happened to the pictures? :(

@SpeedRebirth only 5min he says :D

just a (nother) retarded post.

you are not far behind.

thanks for the write up! doing this tonight!

THANK YOU !! Unbelievable Difference …. And some additional things you might like to try.
 

Thanks to the OP (bova). It saved me from potentially replacing the clutch, or even possibly selling the low mileage Mazdaspeed 6 that I just bought…. I was not happy with the clutch at all.

Let me explain (skip this part if you just want the technical details below).… I bought the car knowing that the early MS6 builds have a TSB against difficult clutch engagement. And the clutch set-up on the one I bought was indeed horrible. It was “grabby” and had a REALLY high engagement point; making driving it extremely challenging. Smooth starts and shifts were problematic and hills became dreaded. You had to constantly think about where the engagement point was; which sapped the fun out of the driving experience. I’ve been driving a stick for about 40 years and this was hands down the worst clutch I’ve ever come across ….. I was resolving myself to having to change out the clutch then possibly reselling my new MS6 and going back to my Mazdaspeed Protege, which is a blast to drive.
I came upon this post and figured I would try adjusting the clutch, which I knew would give it a lower engagement; but I believe it did more than that. Let me explain.

Here is what I did, and what I discovered …. (this worked for me and you can make your own decision whether it is right for you)
The OP was correct the large spring on the top of the pedal assembly is indeed VERY non-linear. In fact, it goes over-center and completely reverses the applied force during the pedal stroke. When the pedal is fully up (clutch engaged) the spring applies a force to help push the pedal away from the firewall. When the pedal is pushed approximately 1/3 of the way down, the spring force REVERSES and actually pulls the pedal down towards the floor. I verified this by removing the pushrod, so it was just the action of the spring acting on the pedal. I have never seen this type of set up before; so I decided to take matters into my own hands …..
1) I adjusted the pushrod adjustment nut to make the clutch engage about1” up from the floor. This lowers the resting pedal height to somewhat below the brake pedal, and results in a short pedal throw. (for me this required that I pretty much bottom-out the pushrod against the lock nut)
2) I removed the large spring on the top of the pedal assembly (the one with the white stripe). I did this because I could see no reason for the need to apply a down-ward force …..so I removed it. (where I had the pushrod adjusted was about at the inflection point of the spring, so it didn’t provide any retraction force).
3) Because the pedal height is so much lower, I had to replace the pedal stop bolt with a longer one (about ½” longer). I screwed it in until I could just feel a small amount of play when I pulled UP on the pedal. This assured that the clutch is not depresses when the pedal is not being depressed. As the OP mentions it is EXTREMELY important to assure some play remains in the pedal. (as a side note: this bolt limits how far the pedal can come back up, since I removed the return spring the pedal does not have a tendency to rise, so it probably isn’t really necessary, but I put it in anyway). There is a another small torsion spring on the pedal assembly that puts a small downward force on the pedal; the internal spring in the master cylinder is more than sufficient to assure that the pedal does not depress the master cylinder.
4) Again because the pedal is now much lower, I had to add a bumper to the pad where the cruise control switch makes contact with the pedal. This switch is used to tell the cruise control to cancel when the clutch pedal is pressed.
5) Finally I added a few felt pads to silence the pedal as it hits the floor board. (FFTs as the OP calls them… mine were 1” diameter heavy-duty felt protector pads that I bought at Home Depot). Because this raised the depressed pedal position slightly from where it was, the Clutch Depression Switch was not fully actuated and the car would not start. To resolve this I added a small spacer (actually a self-stick protective rubber foot) to make the switch actuate fully, and the car will start.

This sounds like a lot of trouble, but the results are WELL worth the effort. I went from being certain the I would have to change the clutch out (and pedal assy per the TSB), and if that didn’t work likely selling the car …. to being able to modulate the clutch (even on steep hills) and breezing thru the gears and really enjoyed driving the car.

I think the modifications did a few key things.
-It lowered the engagement point making it more controllable (more predictable)
-Removed the non-linear behavior of the spring (although I don’t think the force was appreciable, it did add to the unpleasant feel of the pedal)
-The new, lower engagement point (slightly) changed the geometry of the pedal to help alleviate some of the grabbiness (this is an educated guess based on how the geometry is laid out).

Overall I think this is how Mazda should have set-up the clutch. For me is made a phenomenal difference.
Thanks again to the OP (bova) for providing the inspiration for these mods….. I wholeheartedly suggest that everyone make the adjustment, or at least try it. The other mods are for your consideration.

Just a quick up-date….
 

After my initial euphoria with the results of the clutch adjustment, I find I am still unhappy with the On-Off (grabby) clutch, so I am trying to figure out what is going on with the Mazdaspeed 6 Clutch.
I’ve even replaced the original clutch (Pressure Plate, and Clutch Disc), and Flywheel. all with Factory (LUK) parts, per the TSB… no small task and expense I might ad. My MS6 is an early production model so it also called for replacing the Pedal Assembly. After performing these time-consuming (and expensive) fixes it is better, but only incrementally and still less than optimum. FYI: It turns out the TSB recommended pedal assembly is exactly the same as mine, but they have removed a torsion spring, which is easy to disconnect anyway; so save your money, of you have an early production model. II thought I would get that information on the Forum in case it is helpful for anyone. I will try to post some pictures soon.

On a more important note …. I may have found the holy-grail for solving the MS6 clutch issues: I am experimenting with larger clutch slave cylinder bores. The stock slave cylinder bore is ¾” diameter. I am currently running a 7/8” diameter bore, and the difference is Night and Day (the area difference results in a 30% reduction in pedal effort and a 30% increase in the ability to modulate the clutch). It is nearly a drop in replacement, but it does take a few tweaks, and I am not yet happy that the re-work is ready for primetime yet.
After I try a 13/16” bore , and work out the kinks, I will report back (and post some pictures).

Where did you get that larger slave from?
The MS3 slave cylinder also works on the MS6 and it also has a larger bore.

I currently am running a 13/16" dia slave from a Toyota Celica. It is (nearly) a bolt-on installation. I had to cut the rear mounting hole into a slot, use some spacers to adjust the offset, and transfer the boot and pushrod, but other than that it is a drop in installation (took 30 minutes to do, and cost $25).
From what I've been able to determine, you are correct the MS3 uses a larger 13/16" slave (vs 3/4") and probably has the correct bolt spacing ... so it might be a "better" choice long-term). Although, I would have had to find a way to adapt to the Quick-Disconnect fitting for the MS3 (front the threaded MS6 fitting), and they are pretty spendy... so I chose the easier path to do some experimentation (the slave cylinders I have cost under $20 each).
I was running the 7/8" bore for a few days (from a Toyota Supra), and have switched that out for the 13/16" bore. Both offer a lot more clutch modulation, and a lighter pedal. I'll probably switch back to the larger bore in a week of so and see which I like better. And report what I've found.

A friend of mine gave me the a MS3 slave and while it does have the same mounting points to the engine, the port where the line connects is different. The Speed 6 is an screw on and the MS3 seems like it snaps into place and gets held by a clip or something. I guess I could have made it work by getting a new line but I dont know what modifications I have to do to make it work, since the hard line for the Speed 6 have a coil design.

https://lh3.googleusercontent.com/g2...=w1080-h607-no

Yes, you have to modify the hard lines. But its doable.

http://i1211.photobucket.com/albums/...ps7f32fa02.jpg

http://i1211.photobucket.com/albums/...ps07f633a8.jpg

http://i1211.photobucket.com/albums/...ps69c9b415.jpg

http://i1211.photobucket.com/albums/...ps91d56a54.jpg

http://i1211.photobucket.com/albums/...ps1f67a766.jpg

What exactly have to be done?

Sent from my SM-N900T using Tapatalk

Buy a MS3 hard line.
Cut, bend and flare as in the picture.
Screw into corksport SS line.

Thanks, I actually missed the last few pics.. I already got another Slave which I havent installed yet so I will see what is the better option.

No offense, but where did you learn to English? I'm having a hard time trying to follow along with this post

Fixed!

Spanish is my first language, and some times when I write in English I tend write the way I structure sentences the way I would write it in Spanish.

O por eso se leía rara jaja.
Has anyone else swapped slave cylinders?

Thought I would post a few pics of the Clutch Slave cylinders I am messing with .. (hope they show up, it's my first upload of pics):

Here is a comparison of the 13/16" cylinder and the stock 3/4" cylinder:
Attachment 221870

Here it is ready for installation with the MS6 boot and pushrod, with bolts and spacers.
Attachment 221871

Here is a comparison of the 7/8" cylinder and the stock 3/4" cylinder
Attachment 221872

Here it is ready for installation with the stock boot & pushrod, with bolts/spacers and a 3/16" hardline-pigtail.
Attachment 221873

I am going to experiment using these before settling on the bore diameter I like best. Regardless which one I go with, I'll replace the cylindrical metal spacer with a single, solid metal metal spacer ... the spacers I show, I believe should be okay, but a solid metal spacer will be better. I'm pretty confident that there should be no issues with either set-up. I do like the stock MS3 slave installation posted above; if your considering going with the 13/16" slave, I would have complete confidence in that set-up.

Hey guys I need some help understanding this, its almost a full week since I installed the new Pedal, master and slave Cyl. Nothing I have done have made it work. I have bleed the system for more than 4 days, and played with the pedal..

My initial pedal setup was I had it where the rod had almost no gap before it touched the the Master cyl piston.. At this point after bleeding it I was able to get the pedal to return but it still did not had enough pressure.

After reading the how to a second time, this graph got me confused.
http://www.mazdaspeedforum.org/forum/foru...entdiagram.jpg
Does the rod need to be almost out side of the piston hole or the amount of play the graph refers to is the amount of travel before the rod makes contact with the piston? The graph makes it look like the rod its completely out side when the pedal is up which is the part that confused me.


I think I might have a major problem(TOB or PP), but before I go ahead and drop the the money on a new clutch kit I am going to try exchanging both the slave and master just to make sure..

If you have the system properly bled (no air), you should be able to see movement of the clutch fork (and slave cylinder) when someone pushes the clutch. If there is about an inch of movement your the problem is likely elsewhere (but that would seem unlikely to me). If you don’t see movement you don’t have all the air out….
After you get the system bled….
The rod should be just about touching the master cylinder. There should be a small amount of pedal travel before the rod touches the master cylinder. If you look at where the rod makes contact with the master cylinder you should be able to see that the master cylinder is all the way up (not yet depressed) when the pedal is fully released.
Regarding bleeding … not to insult, but just to make sure .... Unless you installed a speed-bleeder (a bleeder with an internal check valve) on the slave cylinder, you’ll need to get some help with bleeding. The procedure: open the bleeder; have someone push down and hold the clutch pedal to the floor; shut the bleeder, then have them release the pedal … repeat until you get a steady stream of fluid (no bubbles).
Something to note: the torsion-looking spring on top of the pedal could be an issue. I KNOW it is an issue with the 7/8” bore slave. The spring is there to assist with the pedal effort: it actually pushes the pedal to the floor. With the 7/8” bore the pedal effort is so light that the spring will not allow the pedal to return fully … so in that case it NEEDS to be removed (again perhaps only with the 7/8” slave). I took mine out as I have a fundamental problem with it 8-). You are probably okay with the 13/16” (MS3) slave you are using. But to be sure, pull up on the pedal and make sure it is returning all the way up.
Here is the basic steps to clutch adjustment:
1) Make sure that the clutch master cylinder is not being depressed; by back out the Clutch Pedal Arm Stop
2) Adjust the rod length so that the clutch pedal is about the same height as the brake (this gives you full stroke for bleeding purposes)
3) Bleed the system
4) Adjust the rod length so that the clutch engagement is where you like it (for me ~1” from the floor)
5) Screw in the Clutch Pedal Arm Stop until you have just a bit of play (assuring that the master cylinder is not being depressed).
(again make sure the torsion-like spring on the top of the pedal assembly is not messing you up; if you have to pull up on the pedal to get it to release fully … if that is the case, you’ll have to remove it)

I want to believe it still have air, I tried bleeding it using the method you described, with the help of a friend and nothing. I am to try to play with the Pedal again and then try to bleed it again.

Here a quick video I took the last time I tried bleeding it with my friend.