Clutch travel issues - PICS & VIDEO
08-31-2011, 02:08 PM
#61
Drifting
Thread Starter
There's no way of extending it!
08-31-2011, 09:34 PM
#64
Burning Brakes
I'll see if I can fish my old dead master cyl out of the bin and measure it up....maybe also take it apart to see if there might be something internal that can limit the travel
09-01-2011, 05:13 PM
#65
Three Wheelin'
Ok, some measurements, from my working, if not 100% perfect, clutch pedal:
At rest the clutch pedal sits 1cm back from the brake pedal. Brake push rod is adjusted to have the pedal about as far from the seat as it will go, only a couple of threads visible at the end of the rod. Frank, if your brake push rod has lots of threads visible the difference between the brake and the clutch might just be because the brake pedal is set really "high".
The accelerator sits 3cm back from the brake pedal but that has plenty of adjustment in both directions so not really a reference point afaik.
Clutch pedal has almost zero movement pulling towards the seat. Consequently the clutch master cylinder rod doesn't extend any further when you pull on the pedal.
With pedal board fitted, the throw of the pedal is 13.5cm. The stopper on the pedal board is set in the "halfway" position. The first 1cm of throw has no real resistance but the clutch rod is moving. Feeling the end of the roll pin there was no play, so 100% of the movement in the pedal converts into movement at the MC push rod. Although I think my plastic bushings are worn as the "axle" does twist a little but we are talking millimetres.
From the very end of the MC rod "ball joint", to the mounting plate, where it bolts to the pedal box, is 13cm. The rod can't be extended any further by pulling the pedal (I didn't disconnect the rod from the bell crank, so I don't know if it is the pedal mechanism stopping it or that is just full extension of the rod). I think this is the key one, if this is significantly less that 13cm, pedal will be sitting much closer to the bulkhead at rest.
At rest the clutch pedal sits 1cm back from the brake pedal. Brake push rod is adjusted to have the pedal about as far from the seat as it will go, only a couple of threads visible at the end of the rod. Frank, if your brake push rod has lots of threads visible the difference between the brake and the clutch might just be because the brake pedal is set really "high".
The accelerator sits 3cm back from the brake pedal but that has plenty of adjustment in both directions so not really a reference point afaik.
Clutch pedal has almost zero movement pulling towards the seat. Consequently the clutch master cylinder rod doesn't extend any further when you pull on the pedal.
With pedal board fitted, the throw of the pedal is 13.5cm. The stopper on the pedal board is set in the "halfway" position. The first 1cm of throw has no real resistance but the clutch rod is moving. Feeling the end of the roll pin there was no play, so 100% of the movement in the pedal converts into movement at the MC push rod. Although I think my plastic bushings are worn as the "axle" does twist a little but we are talking millimetres.
From the very end of the MC rod "ball joint", to the mounting plate, where it bolts to the pedal box, is 13cm. The rod can't be extended any further by pulling the pedal (I didn't disconnect the rod from the bell crank, so I don't know if it is the pedal mechanism stopping it or that is just full extension of the rod). I think this is the key one, if this is significantly less that 13cm, pedal will be sitting much closer to the bulkhead at rest.
09-01-2011, 06:26 PM
#66
Drifting
Thread Starter
Ok, some measurements, from my working, if not 100% perfect, clutch pedal:
At rest the clutch pedal sits 1cm back from the brake pedal. Brake push rod is adjusted to have the pedal about as far from the seat as it will go, only a couple of threads visible at the end of the rod. Frank, if your brake push rod has lots of threads visible the difference between the brake and the clutch might just be because the brake pedal is set really "high".
The accelerator sits 3cm back from the brake pedal but that has plenty of adjustment in both directions so not really a reference point afaik.
Clutch pedal has almost zero movement pulling towards the seat. Consequently the clutch master cylinder rod doesn't extend any further when you pull on the pedal.
With pedal board fitted, the throw of the pedal is 13.5cm. The stopper on the pedal board is set in the "halfway" position. The first 1cm of throw has no real resistance but the clutch rod is moving. Feeling the end of the roll pin there was no play, so 100% of the movement in the pedal converts into movement at the MC push rod. Although I think my plastic bushings are worn as the "axle" does twist a little but we are talking millimetres.
From the very end of the MC rod "ball joint", to the mounting plate, where it bolts to the pedal box, is 13cm. The rod can't be extended any further by pulling the pedal (I didn't disconnect the rod from the bell crank, so I don't know if it is the pedal mechanism stopping it or that is just full extension of the rod). I think this is the key one, if this is significantly less that 13cm, pedal will be sitting much closer to the bulkhead at rest.
At rest the clutch pedal sits 1cm back from the brake pedal. Brake push rod is adjusted to have the pedal about as far from the seat as it will go, only a couple of threads visible at the end of the rod. Frank, if your brake push rod has lots of threads visible the difference between the brake and the clutch might just be because the brake pedal is set really "high".
The accelerator sits 3cm back from the brake pedal but that has plenty of adjustment in both directions so not really a reference point afaik.
Clutch pedal has almost zero movement pulling towards the seat. Consequently the clutch master cylinder rod doesn't extend any further when you pull on the pedal.
With pedal board fitted, the throw of the pedal is 13.5cm. The stopper on the pedal board is set in the "halfway" position. The first 1cm of throw has no real resistance but the clutch rod is moving. Feeling the end of the roll pin there was no play, so 100% of the movement in the pedal converts into movement at the MC push rod. Although I think my plastic bushings are worn as the "axle" does twist a little but we are talking millimetres.
From the very end of the MC rod "ball joint", to the mounting plate, where it bolts to the pedal box, is 13cm. The rod can't be extended any further by pulling the pedal (I didn't disconnect the rod from the bell crank, so I don't know if it is the pedal mechanism stopping it or that is just full extension of the rod). I think this is the key one, if this is significantly less that 13cm, pedal will be sitting much closer to the bulkhead at rest.
I'll have a measure up tomorrow eve! We'll see...
09-01-2011, 06:40 PM
#67
Three Wheelin'
I'm out of poxy image quota .... flickr to the rescue
http://www.flickr.com/photos/67059665@N07/6104500460/
http://www.flickr.com/photos/67059665@N07/6103955715/
http://www.flickr.com/photos/67059665@N07/6104500460/
http://www.flickr.com/photos/67059665@N07/6103955715/
Last edited by alexjc4; 09-01-2011 at 06:56 PM.
09-05-2011, 08:47 PM
#68
Drifting
Thread Starter
Still haven't got round to measuring up, will have some time soon. Thanks for the pics Alex. PS I'm very jealous of your symmetrical pedal arrangement right now!
Completely by coincidence I fell upon this post, trouble is I can't understand a thing he's going on about - but it seems like a lead? Can anyone decipher the post? And what the hell is a "kinematic construction" ?!?!!?!!!??!??!
"
What I did next is very easy.........and......it worked without any costs.
No replace of cilinders, clutch or any kind of those things.
Take a 4mm [imbus on Dutch] tool and turn the srew on the left side of the kinematic construction from the clutch pedal, 4x 360 degrees to the left.[against the clock]
What you do, is make free space that the pedal usualy has before the clutch cylinder starts to work, smaller.
This it enough to have plenty free space left for you clutch cylinder starts to work, and enough to move out of your 'flip over' area!!!
It works fine!!!! I tested it this afternoon, the clutch worked as it should be, no hanging pedal any more.
(MY CAR NEEDED 4X 360 DEGREES TO THE LEFT, MAY BE OTHER CARS NEED 3X 360 OR 5X 360 DEGREES TO THE LEFT!!]
I am very happy that I can tell you all this, may be somebody can use this also on his car.
This is risk free, as long as us leave enough free space before the cylinder starts to work!!!!
[otherwise you can damage your clutch, it will not come totaly free!] "
https://rennlist.com/forums/964-foru...al-solved.html
Completely by coincidence I fell upon this post, trouble is I can't understand a thing he's going on about - but it seems like a lead? Can anyone decipher the post? And what the hell is a "kinematic construction" ?!?!!?!!!??!??!
"
What I did next is very easy.........and......it worked without any costs.
No replace of cilinders, clutch or any kind of those things.
Take a 4mm [imbus on Dutch] tool and turn the srew on the left side of the kinematic construction from the clutch pedal, 4x 360 degrees to the left.[against the clock]
What you do, is make free space that the pedal usualy has before the clutch cylinder starts to work, smaller.
This it enough to have plenty free space left for you clutch cylinder starts to work, and enough to move out of your 'flip over' area!!!
It works fine!!!! I tested it this afternoon, the clutch worked as it should be, no hanging pedal any more.
(MY CAR NEEDED 4X 360 DEGREES TO THE LEFT, MAY BE OTHER CARS NEED 3X 360 OR 5X 360 DEGREES TO THE LEFT!!]
I am very happy that I can tell you all this, may be somebody can use this also on his car.
This is risk free, as long as us leave enough free space before the cylinder starts to work!!!!
[otherwise you can damage your clutch, it will not come totaly free!] "
https://rennlist.com/forums/964-foru...al-solved.html
09-05-2011, 09:26 PM
#69
Burning Brakes
I think what he's done, is adjust the tension on that massive return spring arrangement behind the pedal to increase the spring rate and push the pedal past this sticking point (I didn't even know it was adjustable, but it sounds like that's what he's done).
In your case, Frank, it sounds like it's not quite the same issue...
01-12-2012, 11:56 PM
#70
Three Wheelin'
Did you ever get this worked out?
It is not uncommon. There was a Porsche TSB that covers it:
As I remember, clutch travel should be 14.5-15.5 cm to achieve full disengagement. If you are only getting 13-14cm it's not enough. There is, apparently, some adjustability, however it isn't clear where since it was a common enough problem to issue a TSB. Were you able to get full excursion?
It will make a big difference in shifting, and who doesn't love shifting?
It is not uncommon. There was a Porsche TSB that covers it:
As I remember, clutch travel should be 14.5-15.5 cm to achieve full disengagement. If you are only getting 13-14cm it's not enough. There is, apparently, some adjustability, however it isn't clear where since it was a common enough problem to issue a TSB. Were you able to get full excursion?
It will make a big difference in shifting, and who doesn't love shifting?
01-13-2012, 08:45 AM
#71
Drifting
Thread Starter
Did you ever get this worked out?
It is not uncommon. There was a Porsche TSB that covers it:
As I remember, clutch travel should be 14.5-15.5 cm to achieve full disengagement. If you are only getting 13-14cm it's not enough. There is, apparently, some adjustability, however it isn't clear where since it was a common enough problem to issue a TSB. Were you able to get full excursion?
It will make a big difference in shifting, and who doesn't love shifting?
It is not uncommon. There was a Porsche TSB that covers it:
As I remember, clutch travel should be 14.5-15.5 cm to achieve full disengagement. If you are only getting 13-14cm it's not enough. There is, apparently, some adjustability, however it isn't clear where since it was a common enough problem to issue a TSB. Were you able to get full excursion?
It will make a big difference in shifting, and who doesn't love shifting?
All in all a worthy upgrade if your pedal assembly packs up.
