wrong clutch slave pushrod?

[dtbaker61]

everyone has been very helpful.... and helped me make my mind up that either something is completely worn down, backward, or mismatched inside the tranny like perhaps the wrong clutch arm.

However, I am not going to take it apart right now to find out. I am going to slap on the new slave with an offset to move it a little closer, and drive the car thru the summer...

thanks again!

 

[Alpine 1789]

ok, my clutch slave saga continues, and the plot thickens. I got a new clutch slave (from taiwan thru VB), which has identical dimensions to the Lockheed I removed so I am accepting the slave itself is probably the right one.

I am sure this slave will be fine for now and get you through until your car is back on the road, but I wouldn't trust it long term. I bought one of those a few years ago when VB had them on sale. It worked just fine for a couple of years, then died one day on the road when the piston pushed out just far enough to let all of the fluid leak out. I was able to get going again by pushing it back in, refilling the master and bleeding the system, but I replaced the VB cylinder with a rebuilt stock one as soon as I could after that. (As I recall, the innards of the VB slave were unique and I had no idea where to even start with a rebuilding kit.)

When you have the clutch problems sorted out, I recommend cleaning up your original slave and seeing if it is rebuildable. If so, I'd carry it in the car for a spare, just in case your VB slave is no better than the one I bought.

 

[jumpinjan]

Mike,
I think that was Scott Christie's Series 3 and not Ian's Harrington. Here's the thing on these clutch arms.
If you use:
Series I, II 8" coil spring pressure plate you use: Short pedestal/large fork
Series 3, 8" diaphram pressure plate................; Tall pedestal/large fork
Series V, 7.5" diaphram pressure plate..............; Tall pedestal/small fork
Jan

Here's something to consider. When Ian's former B type Harrington was going back together I was a Jan's place while the engine and transmission were going back together. It had an original pressure plate assembly at the time that was being replaced with a new one supplied from one of our regular suppliers. And the release bearing arm moved too far.
The reason was that the replacement pressure plate was not as tall as the original, by half an inch or so, so the fork had to move further forward to work making the required slave travel too much.
I don't recall what we did, I think the pedestal was swapped for a later taller one and the forks swapped. But I can't say absolutely for sure as it's been too long.

 

[dtbaker61]

thanks jumpin.... excellent info for when I do pull things apart to see what I actually have.

In the meantime, I started putting things back together with a 1" offset, but am a little concerned about the amount of pressure the internal spring in the slave applies to the clutch arm when at rest.... It SEEMS like a lot, but maybe is probably only a few pounds.

I am looking for a little confirmation that when at rest there is 'significant' pressure from the slave holding the pushrod effectively with 'zero clearance'. I t is not a LOT of pressure, but seems like it would definitely keep things in contact all the time. Is this ok?

 

[dtbaker61]

ok, got it back together... thought I would summarize a few things n case people are searching threads later. I ended up added 11 washers and using 3" long 5/16 bolts, which offset the slave almost exactly an inch PLUS the thickness of the bell housing flange. It is a little more than required, I think 3/4" or 7/8" would have been fine too. With pedal at full depression, the slave piston is still well back in the cylinder out of danger of spitting out the back end.

- the 'throw' of the slave cylinder is only abut 1/2" from rest to clutch pedal to the floor. It seems BARELY enough to disengage. I am probably going to try moving the pedal pushrod pivot to the other hole to see if it generates a little more throw.

- I did install the bleeder at the top on the slave, and it bleeds pretty steady with just gravity... no need to pump this one!

- I did file/sand the pushrod shaft smooth so it wouldn't rip up the slave boot, and greased

 

[Ken Ellis]

Dan, I wouldn't worry about the short "throw" of the system. Even though you're at 1/2" at the end of the yoke, and the yoke is probably about a 2:1 pivot arm -- meaning your travel at the throwout bearing end is 1/4" (1/2 of the slave cyl. throw) all that's really necessary is for the throwout to depress the springs enough to move the clutch parts apart enough that they don't touch. That means 1/8" is enough, or even 1/16" or even less... Just enough that any runout of the flywheel/clutch plate system doesn't cause enough drag to rotate the trans shaft.

It's not unusual to expect the slave to have much more travel -- because your foot sure moves a lot under the dash when actuating the clutch. But there's a ratio there, too -- due to the pivot point of the pedal in relation to the actuation point of the clutch master.

The only adjustment I need to make on mine is to move the clutch friction point (with respect to pedal travel) a little higher off the floor. Right now, all the action seems to happen in the bottom 1" of pedal travel. (Might be a little more, but it's way down there.)

The most important bit is, of course, you're back on the road for the holiday weekend (hopefully!)

Ken

Upon reflection -- another possible source of throw "compression" may be the ratio of slave piston diameter to the master piston diameter. Are your old slave and new slave cylinders the same diameter? If the new one's bigger, it'll move less than the old one.

 

[Thor 1211]

The throw arm

My series V has an aftermarket slave and it seems to work fine except when freewheeling in neutral the clutch rattles like a can full of rocks. The slightest depression on the clutch silences it. The clutch arm seems to be loose on the pivot pin and you can rattle it around with your hand and it seems that there is no tensions at all on the system until you depress the pedal al little. Im thinking that if I put a couple of washers behind the slave I can shim it forward and put pressure on the system and silence the chatter. This would mean that the bearing would be in full time contact with the release plate. Is this ok?

 

[puff4]

Dan, maybe I missed this somewhere, but did you ever check the end-play on your crankshaft?

 

[Thor 1211]

end float

The end float is at 005 which is right on the money. So when I found that out I went looking elsewhere and found this sloppy clutch arm. If it's not going to cause premature wear to the throw out bearing I'm going to put a little contact pressure on the arm to take up the slop.

 

[dtbaker61]

Dan, I wouldn't worry about the short "throw" of the system. Even though you're at 1/2" at the end of the yoke, ... Right now, all the action seems to happen in the bottom 1" of pedal travel. ... another possible source of throw "compression" may be the ratio of slave piston diameter to the master piston diameter. Are your old slave and new slave cylinders the same diameter? If the new one's bigger, it'll move less than the old one.

new slave has same bore as old cruddy one. seems to shift fine, just BARELY disengages when I depress pedal to the floor, but seems ok. I am curious to know if travel of the slave yoke should be more than 1/2"; if so, then I'll need to take a closer look at the master! Seems 'good enough' for now though.

 

[dtbaker61]

Dan, maybe I missed this somewhere, but did you ever check the end-play on your crankshaft?

I could not feel any play on the pulley. but it is pretty awkward to get much leverage on that. I did NOT pull oil pan or anything like that... I really just want to get thru the summer and then pull things apart over the winter!

 

[dtbaker61]

thought i would post a picture of the replaced slave cyl. It is a copy from Taiwan that I got from VB ($40) and measured the same as the lockheed I removed for stroke (close to 2" possible) and bore (1") diameter.

The washers add up to pretty close to 1" offset. I think I could have used less, but was allowing for an inch of travel and not wanting the slave to pop out the end. Turns out the travel is only about 1/2", so I probably could have gotten by with 1/2" of washers... just didn't feel like undoing everything again.

 

[mickjj]

Your push rod actually looks longer than the rod in my SV. My pushrod is 4" from end to the clevis pin, yours looks to be 4.5"

As others have suggested you may not have a SV release fork/pedestal. Especially the pedastal, as I think maybe the earlier versions are shorter and would put the release lever farther away causing your problem, maybe somebody else can clarify this.

Here is a pic of the stuff from my car:

I have a somewhat similar dilema in the fact that the fork and release bearind are larger than the contact area on the pressure plate. I have a fork of a series V ( mine is Series I) which matches the plate. I am right in assuming I can just swap the forks?

 

[mickjj]

OK I have bitten the bullet and changed the arms and installed a new bearing. I have now relised that the hole diameters on the bearings are different the new(all synchro) one being 1/8" smaller though the shafts are the same diameter. Will this cause a problem?