Clutch again

Rocky If you look the bone is the same way around as the one on the provamo site in the first Pic.

Sent from the Clutch asylum UK.

I am hesitant about adding my thoughts as it seems I get things more confussing, BUT, it is not in my nature to not jump in

as for the master cylinder rod, there was a TSB article that implies the original had to be replaced with a shorter one (and remove spring to prevent it going coil solid)

my "opinion" is that the MC rod adjustment is to get you close, but the adjustment has to be to set the initial angle. If too shallow, the link LOCKS, Too great, and the full stroke is reduced

Thanks for that info, I will again remove my clutch master cylinder and check its length.

Feeling a little better now I have a definite to chew on.

Peter,

Your "dogbone" is installed correctly, so you can rule that out as a possible cause of your clutch difficulties. You're on the right track. It looks to me like your clutch M/C pushrod is too long, causing the linkage to bind when you depress the pedal. This is how it should align, if your pushrod is the correct length.

I can't help myself, even though no one proably cares, I'll post the graph of the linkage kinamatics I did back when I was still able to do such.

IF the clutch rod is adjusted so that "b & c" are in line (the white line), this is the 0,0 of the graph an implies that even though the amount of mechanical travel advantage is its greatest, the force required to push the pedal is tremendous (ie if is LOCKED).

the clutch rod needs to be adjusted so the starting angle is as indicated by the white arrow. HOWEVER, if the angle is to great, the mechanical advantage is nill. this is the graph for when pedal travle is greater than 1

Thanks David, thats something, also I had the rod adjusted at 79mm which I thought was its shortest length!

After removing the cylinder I found some more adjustment to go to 73.9mm

will fit tomorrow, and cut the rods extra unwanted threads,

JFB thanks for the rod length post again, your reasoning is logical, but I am a simple soul and still find "pressure beyond" difficult to understand in Hydraulics!

best Pete.

was there a spring on the MC rod?

Hey JFB,

In your diagram that shows the effort reduction kit geometry, the "dogbone" is backwards! The part number should be visible from the passenger side of the pedal assy.

I got that photo online from "JB1490".

During Peter's last clutch discussion, the fact the dogbone was not symetrical was brought to my attention.

the sad thing I discovered at that time was I could not remember how I did the calcs to see how much differene it makes.

If "c" is made longer (by reversing dogbone, that might prevent the ability to adjust for the "b & c" to go straight line and lockup

quote:

Originally posted by JFB #05177:
was there a spring on the MC rod?

No the spring had gone.

quote:

In your diagram that shows the effort reduction kit geometry, the "dogbone" is backwards! The part number should be visible from the passenger side of the pedal assy.

That particular "dog bone" does not have any numbers on either side. As pictured above, it has been in service for 40k miles.

John

John,

It's still the wrong way around. The lower hole should be offset towards the front of the car. It will work both ways but it works better in the correct orientation.

Here is the News.

I fixed the length of the MC rod at 73.9mm
My Sachs clutch is light as a feather, and gears engage well.

I have 1mm play between the fingers and the throw out bearing, when the clutch is engaged.

AND its as light as a feather to operate.

so thanks to all you forum people who have put up with my Clutch woes for far too long, your assistance HAS been extremely valuable.

Thanks also to Roland Jaekel in Hamburg for his quality products that worked so well for me.

If anyone would like a trip over to Manchester England sometime the beers are on me!!!

quote:

Originally posted by David_Nunn:
....but it works better in the correct orientation.

(First PLEASE David, don't take my comment serious, but as the jocularity intended)

One of my pet peeves with the "techincal" reports of others is the phrase "made it better"...My peer review reply is "... you need to quantify the degree of better"

Peter, on my wish list will be that beer (and I don't drink)

Here's what I based my information on. Mike Drew is the author of this info document.

quote:

Originally posted by JFB #05177:

quote:

Originally posted by David_Nunn:
....but it works better in the correct orientation.

(First PLEASE David, don't take my comment serious, but as the jocularity intended)

One of my pet peeves with the "techincal" reports of others is the phrase "made it better"...My peer review reply is "... you need to quantify the degree of better"

Peter, on my wish list will be that beer (and I don't drink)

I can do saspirella.
again my clutch isn't a bit better its working properly! Geronimo I believe is said in such circumstances.

I replaced mine recently and purchased a aluminum one. Arrow points forward

Linkages installed

Another picture

quote:

Originally posted by GT5KR:
I replaced mine recently and purchased a aluminum one. Arrow points forward

I am amazed that the original has no method of lube when the forces generated are so high.

So would you mind letting me know where you bought the alloy one from and its cost?

best Pete

with the alloy piece, with its needle bearings, are HARD pins provided.
normal steel pins will "knurl" with the concentration of contact force

Every designer prioritizes their objectives and considerations differently. I have never been fond of element bearings in such an application

Peter, I bought this for 90 US from Pantera Performance in Colorado. Before installing the pins just lube them up with a smear of grease.

JFB, I know what you mean, I was a little skeptical about this too. But they say it was good as the original bellcrank.
This is my third bellcrank, the other had elongated holes and the machine shop made a bushing for it, but only lasted a few years.
I'm trying this one out.

Thanks for the info GT5KR.

it may help a pal now having his casting rebushed

I would think it an improvement over the Standard unit just because it has lubrication.
and the cost isn't too prohibitive.