DIY - Easy clutch grab adjustment (~10 mins)

[HunterGreene]

I have my guess, but what does removing the spring do? I mean what is the physical difference, not just "it improves the feel."

Based on what I am reading, the spring makes the pedal come all the way up, whereas without the spring, the pedal only comes back as far as the clutch spring itself would force it. Only downside is that it could "flop" around at the top of the stroke. Am I close?

[Subscap]

Originally Posted by HunterGreene

I have my guess, but what does removing the spring do? I mean what is the physical difference, not just "it improves the feel."

Based on what I am reading, the spring makes the pedal come all the way up, whereas without the spring, the pedal only comes back as far as the clutch spring itself would force it. Only downside is that it could "flop" around at the top of the stroke. Am I close?

That's pretty much it, yes.

The reason that the feel is improved is that the factory pedal return spring is powerful enough that it (in my opinion, completely) masks the force from the clutch spring.

The slop is really minimal, likely no more than a quarter to half an inch at the top. The perfectionist in me would really like to resolve that slop, even though I don't believe it's enough to cause any functional issues. Truly after a few days I've stopped noticing it as much.

[HunterGreene]

Originally Posted by Subscap

That's pretty much it, yes.

The reason that the feel is improved is that the factory pedal return spring is powerful enough that it (in my opinion, completely) masks the force from the clutch spring.

The slop is really minimal, likely no more than a quarter to half an inch at the top. The perfectionist in me would really like to resolve that slop, even though I don't believe it's enough to cause any functional issues. Truly after a few days I've stopped noticing it as much.

Thanks alot, nice explanation. So do you think removing this spring could cause premature wear of the clutch spring over the long term, as the load of returning the pedal to the "out" position is now fully on the clutch spring instead of supported by both?

[Subscap]

Originally Posted by HunterGreene

Thanks alot, nice explanation. So do you think removing this spring could cause premature wear of the clutch spring over the long term, as the load of returning the pedal to the "out" position is now fully on the clutch spring instead of supported by both?

The pressure plate springs are going to be just fine.

The only plausible concern (read: incredibly unlikely) would be extra clutch disk wear from the weight of the pedal itself possibly exerting pressure on the hydraulic system and ever so slightly disengaging the clutch. Again - highly unlikely this would actually happen.

[HunterGreene]

Originally Posted by Subscap

The pressure plate springs are going to be just fine.

The only plausible concern (read: incredibly unlikely) would be extra clutch disk wear from the weight of the pedal itself possibly exerting pressure on the hydraulic system and ever so slightly disengaging the clutch. Again - highly unlikely this would actually happen.

I agree, the only way I could see this having significant impact is if the pressure plate springs are wearing out, which likely means your clutch is just about done anyways.

...so I think I may look into removing the spring now

[Subscap]

Originally Posted by HunterGreene

I agree, the only way I could see this having significant impact is if the pressure plate springs are wearing out, which likely means your clutch is just about done anyways.

...so I think I may look into removing the spring now

You're going to love actually having feedback from the clutch! Keep us updated

[Hyper4mance2k]

Originally Posted by Subscap

The pressure plate springs are going to be just fine.

The only plausible concern (read: incredibly unlikely) would be extra clutch disk wear from the weight of the pedal itself possibly exerting pressure on the hydraulic system and ever so slightly disengaging the clutch. Again - highly unlikely this would actually happen.

MTEC says they have been seeing premature seal failure in the slave due to spring removal, hense their light weight spring. Though, that could all be marketing. I want a spring about as strong as a ball point pen, one that just eliminated the slop. After reading the MTEC reviews, I doubt I'llbe happy with it.

[Subscap]

Originally Posted by Hyper4mance2k

MTEC says they have been seeing premature seal failure in the slave due to spring removal, hense their light weight spring. Though, that could all be marketing. I want a spring about as strong as a ball point pen, one that just eliminated the slop. After reading the MTEC reviews, I doubt I'llbe happy with it.

Not calling them out, but I sure would appreciate seeing proof of MTEC's claim (photos of wear and how many cars)... I may just be an old salty whenever I hear product businesses claims without proof - graphic designer created HP graphs don't count!

I'm still playing with ideas to get a super weak spring hooked up to ONLY eliminate the slop. If/when I get around to it, I'll definitely update.

[Hyper4mance2k]

Originally Posted by Subscap

Not calling them out, but I sure would appreciate seeing proof of MTEC's claim (photos of wear and how many cars)... I may just be an old salty whenever I hear product businesses claims without proof - graphic designer created HP graphs don't count!

I'm still playing with ideas to get a super weak spring hooked up to ONLY eliminate the slop. If/when I get around to it, I'll definitely update.

I always love seeing dyno graphs where HP & torque do not cross at 5252 RPM. I like it even more when people argue that they don't always cross at 5252 RPM.

[kbye]

FWIW I've had the MTEC spring in for a couple weeks and I'm quite happy with it.
The MTEC is just the right amount of compression, anything weaker probably can't hold up the weight of the clutch pedal.
I don't buy into the premature seal failure explanation, though. I wouldn't expect any long-term issues running springless but I don't claim to be an expert on the subject either.

[DocWalt]

The seal failure thing is baloney. The force to push on the master cylinder is coming from somewhere, either the assist spring or your leg...

[Ultramaroon]

Originally Posted by HunterGreene

I have my guess, but what does removing the spring do? I mean what is the physical difference, not just "it improves the feel."

Based on what I am reading, the spring makes the pedal come all the way up, whereas without the spring, the pedal only comes back as far as the clutch spring itself would force it. Only downside is that it could "flop" around at the top of the stroke. Am I close?

The assist spring is a compression spring that is part of an overcenter mechanism. Think of any old toggle switch. When you flip the switch slowly it first resists the motion. At some point, when the spring is at maximum compression the mechanism rolls "over center" and then the spring forces the switch the opposite direction.

At factory height adjustment, the clutch assist spring is ever so slightly over center so it pushes the clutch pedal away from the floor.

When the clutch pedal is depressed, very early in the arc, the mode changes so the spring, as it decompresses, applies force in the direction of pressing the clutch pedal. It pushes the same direction as your foot.

This is why some people who have aggressively lowered their clutch pedals without removing the spring report having to sometimes pull back on the pedal to raise it completely. The device never gets to that neutral point where it no longer applies downward force on the pedal.

edit: No. My above statement is BS. The mode does change early in the arc but the motion profile is shallow until well into the pedal arc. The assist spring doesn't do much until the pedal is about halfway depressed.

I believe this may also be the cause of some of these premature throwout bearing failures but have no hard evidence to support the theory.

edit: Nope. Nevermind. I was wrong.

[Celadrielas]

Originally Posted by Ultramaroon

The assist spring is a compression spring that is part of an overcenter mechanism. Think of any old toggle switch. When you flip the switch slowly it first resists the motion. At some point, when the spring is at maximum compression the mechanism rolls "over center" and then the spring forces the switch the opposite direction.

At factory height adjustment, the clutch assist spring is ever so slightly over center so it pushes the clutch pedal away from the floor.

When the clutch pedal is depressed, very early in the arc, the mode changes so the spring, as it decompresses, applies force in the direction of pressing the clutch pedal. It pushes the same direction as your foot.

This is why some people who have aggressively lowered their clutch pedals without removing the spring report having to sometimes pull back on the pedal to raise it completely. The device never gets to that neutral point where it no longer applies downward force on the pedal.

I believe this may also be the cause of some of these premature throwout bearing failures but have no hard evidence to support the theory.

I actually decided I was going to try to reset this back to stock. I've done my best but I've been driving with a slightly lowered clutch pedal for about a year, so I've forgotten. during a different service, I asked the dealership to see if they could "Check the clutch height for me".

My paperwork came back with the folowing note: "There is no clutch adjustment for this vehicle. While slightly lower than other FRS on the lot, there appears to be nothing out of alignment or harmful with the vehicle."

--- I guess, to me, that means if it WAS aggressively low, it could be damaging to the vehicle, in theory. Or the toyota mechanic was a complete idiot. But you know... which ever

[Atticus808]

I tried to do the clutch adjustment but the 12mm was so damn tight I couldn't loosen it. anyone else have that issue?