Hi Folks,
I am fitting a type 9 that has had its shifter position to fit into a +2. It’s not a voigts modified box.
Anyhow it had has a longer V6 input shaft and therefore a spacer between the box and bellhousing. It is also has a Milton concentric clutch slave fitted.
My long shot is… does anyone have a similar set up and knows what spacers the slave needs to give the required the correct tolerance to the pressure plate fingers.
Tim
Tim
I tried this years ago and it wouldn’t fit , rear mounting , has yours been removed?
John 
I’ve done a concentric cylinder installation (using a different gearbox). I would say there is no ‘universal’ spacer dimension as it will depend on the gearbox used, the thickness of the adaptor plate used, and the specific design of the concentric slave cylinder. So you need to measure the distance from the throwout bearing face to the operating interface (fingers) of the pressure plate and then fabricate a spacer (or spacers) that is that distance minus whatever the normal throw out bearing clearance should be (1-2mm?). Obviously it’s nearly impossible to do this measurement with everything assembled, so one way is to install the bell housing and adapter plate and measure from the rear mounting face to the pressure plate, then measure from the gearbox to bell housing mounting face to the throwout bearing face (with the throwout bearing fully retracted, of course). Also obvious is that careful and thoughtful measurement is required here, so your old school ruler won’t do.
OK. I kinda thought this as I also suspected that the clutch pressure plate would have significant influence. Luckily you can buy spacers. So will get measuring.
Tim
Hi
I went through this recently with my type 9 with concentric clutch. Mine also has had the lever relocated into the correct spot. I didn’t have the longer input shaft on this box (but do on another) have you considered cutting it down to remove the need for a spacer on the bellhousing?
If the box is out of the car there is a way to measure for the concentric clutch spacer. I cannot remember what it is but the information is out there. I bought a 12mm spacer but it was too big and had it turned down to 7mm I think it was. You can get 7mm ones I think but it was no prob for me to have the work done. It does make a difference whether the clutch is self adjusting or not as if is not you will have to make sure you have enough travel to accommodate for clutch wear over time. I used a Mondeo mk1 clutch which was not, but mine is a Zetec engine. I did use one of those cheap inspection cameras to make sure I had clearance between the bearing (a Saab item) and the clutch cover forks and to see that the the mechanism behaved as expected. I also have a remote bleed for the clutch slave to make bleeding super easy.
By the way, does your type 9 have a spring on the lever? Mine does and it is far too strong. I have to use two hands to push the lever down to get into reverse. I’m looking to get a weaker spring and are seeking suggestions. The one one on there looks like a valve spring.
I might have written some of this up on this site. I cant remember. I do have videos of the clutch mechanism at work somewhere.
All the best
Berni
Thanks folks.
I too use one of the cheap micro cameras (see attached image)
The cylinder came with a few spacers but it is still too short so have ordered a larger spacer from burton power. Hopefully by using different combos I can get it to fit.
Tim
OK fitted a 25mm spacer and it gives me about 3mm gap between the thrust bearing and the tips of the clutch cover fingers.
I think that’s enough.
Tim
Hi
That sounds like it will be fine! What are you doing about a propshaft?
All the best
Berni
I have a modded one which came with the box when I bought it. The only other concern I have is that the previous owner of the gearbox claimed to have run it in an elan but when I mated it up to the engine the input shaft was too long. So I have fitted a spacer between the box and the bell housing. Question I now have is it too long now. Will try test fitting this weekend so we will see.
Tim
Can I ask a very amateur question?
I have installed two concentric slaves, one in an Elan. Both had a spring which pushes the bearing toward the fingers. Both bearings settle lightly on the fingers when the clutch pedal is out. The bearing spins in the normal course of operation similar to a lever style slave.
If I were to have a gap at rest then there would not be enough stroke length to get complete disengagement so I made ally spacers to get the right movement of the slave. The manufacturers of the slaves also warn not to have the extended length close to the end of the tube in the middle of the slave. The Elan one has operated for 3000klm and clutch works well. The other is in a Porsche which also operates ok.
In both I installed larger master cylinders to get the correct pedal movement and weight I wanted ie short and firm.
As Terry mentions concentric slaves work a bit different compared to the external style with an adjustable rod. As wear happens they need to self adjust, and this moves the piston deeper into its bore. The spring Terry mentions is used to keep the thrust bearing pressed lightly against the clutch fingers and the fluid behind the piston takes care of the adjustment. The question is, and I don’t have the answer, how much further will the fingers move towards the piston as the clutch assembly wears? I believe the pressure plate finger lever ratio is somewhere between 1.5:1 and 2:1 So this should give you 1.5-2.0mm of wear allowance with a 3mm gap.
Tim,
As Terry and Snowy stated the adjustment is automatic. I shared your concern about movement and the lever ratio that Snowy mentions and was not happy with my calculations. I remembered advice from my working life “do not calculate what you can measure”. I removed the flywheel to the bench, assembled the clutch pressure, friction plates with all bolts installed and used a large bolt through the centre of the flywheel to the pressure plate fingers so that I could measure how far the fingers/thrust bearing needs to move in order for the friction plate to become free. Being me I did not make any notes, but I was surprised at how little movement of the slave was necessary. I suspect that when the pressure plate is bolted up the diaphragm spring changes shape in some manner that I don’t understand to give a different lever ratio to my initial calculation. Next I assembled gearbox to engine with clutch and checked that it worked hydraulically which it seems to.
Hope this helps,
Richard Hawkins
I checked the positions of the fingers with the clutch cover bolted on to the flywheel with the friction plate and without the friction plate. The movement of the fingers was not a lot. So 3mm clearence shoule be enough.
Tim
