Stag clutch pushrod length?

[Mike7777777]

Hi

The clutch slave pushrod and piston disappeared from my car whilst driving. The "U" link and pin was left on the operating arm. I've replaced the slave cylinder and slave pushrod, I've connected the rod to the middle hole on the operating arm. The piston pops out of the cylinder before the clutch releases. I now realise that the original pushrod had been modified, there is evidence of poor welding on the "U" link where it attaches to the rod, in fact I can't see any clean metal at the break!

The replacement pushrod overall length is 152mm / 6".

The operating arm has 15mm of freeplay, the distance from the centre of the centre hole on the operating arm to the opening of the slave cylinder is 130mm minimum and 145mm maximum.

Receipts show that the previous owner fitted a new clutch from Rimmers approx 12 000 miles ago. The clutch was working OK before the pushrod and piston went missing, although selecting reverse was bit crunchy if rushed.

Either:

a)  the modified pushrod was longer than the standard pushrod, the modified pushrod has broken and all I need do is fit another modified pushrod (hopefully!)

or

b) the operating mechanism for the clutch has broken within the bellhousing, perhaps the pin bolt for the clutch release fork, the operating arm has then travelled beyond full extension and allowed the pushrod to fall out of the slave cylinder and hit the ground, closely followed by the piston  .... which means gearbox out for repair :-(

I'd appreciate any comments regarding the length of the pushrod and the positioning/freeplay of the operating arm.

[wakaday]

I have had this happen once before on a customers car.. The  owner had tried all sorts of ways to make the clutch bite higher up on the pedal. He tried different lengths of rods and even spacing the slave cylinder but his problems lay a lot deeper. The cause was excessive Crank Endfloat. So much that the Thrust washers had fallen out and the Crank Shaft was milling the block everytime the Clutch was depressed. This resulted in both the Crank and Block being Scrap.
If you get it all working again, then check your endfloat before its to late just in case you have the same problem.

[Mike7777777]

Thanks wakaday, the receipts show that a Rimmer reconditioned engine was also fitted about 12 000 miles ago, so fingers crossed it's not excessive endfloat to the crank. Can the endfloat be checked easily?

I think the problem is a broken pin bolt on the clutch release fork, so that's my Christmas break sorted then, several (or many) hours on the floor of a cold lock-up underneath the Stag :(

[shenderson]

Crankshaft endfloat can be checked by levering the crank pulley forward and backwards.  I don't have the spec to hand but can find out if required, but any more than a few thou would be excessive!  I haven't heard of this problem affecting Stags but it was quite common on the Triumph 6 cylinder engines.

Much more likely to be the pin on the release fork, which has a habit of breaking.

Steve

[wakaday]

I must admit that  its the first and only Thrust Washer failure that I have come across on the Stag V8 but I have seen a couple on the Slant Dolomite Engines.

A quick way of checking when its all back together is to have someone press the Clutch up and down  with the Engine running and stare at the front Crank Pulley. If you can see it moving in and out  with the Clutch being pressed then you have problems.