How To: Clutch Pedal Adjustment

[zogy]

That looks like plenty of play as far as I am concerned. So I don't think it's just trapped air. Trapped air would basically show up as a mushy pedal and inadequate clutch slave travel. You look like you have plenty of motion, so I think you need to look elsewhere.
If the clutch is not releasing, then you've got something else going on; I would venture to guess: broken fork, throw-out bearing failure, or pressure plate issue. Do you feel any resistance in the pedal (to indicate that it is doing something ... like depressing the spring in the pressure plate)?

[f15ms6]

Originally Posted by zogy That looks like plenty of play as far as I am concerned. So I don't think it's just trapped air. Trapped air would basically show up as a mushy pedal and inadequate clutch slave travel. You look like you have plenty of motion, so I think you need to look elsewhere. If the clutch is not releasing, then you've got something else going on; I would venture to guess: broken fork, throw-out bearing failure, or pressure plate issue. Do you feel any resistance in the pedal (to indicate that it is doing something ... like depressing the spring in the pressure plate)?

The last pedal setting I had when I recorded the video, it only had it had only 1/4 of the normal pressure, just enough for the pedal to slowly come back up.. Yeah I was afraid it was the throw out bearing or pressure plate..

I am just going to go ahead and just order it.. I have 131k so sooner or later I was going to need a clutch job. It sucks because the clutch felt good for the mileage, until the pedal broke and shit hit the fan..

[mpslover]

Originally Posted by zogy 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.

Did this mod to my MPS 6 today and it now feels like a normal clutch. The helper spring removal makes all the difference and the pedal adjustment gives a better grap height.

[richard nash]

On my 2012 Speed 3, I have trouble engageing the clutch on steep hills. The clutch does not egage until my foot is way off the floor. This makes it difficult to get started without rolling backwards (risk of hitting the car behind me) or giving it excessive gas (risk for clutch wear). I drive another 2007 Mazda 3 (not a speed) & I have no problem on the hills. Can the engagement point be adjusted?? Is this a sign of clutch wear (car has 45000 miles)??

[himurax13]

No.

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