Clutch release bearing question

[billjam]

For my 3.6 conversion, the stack of parts I have pulled together looks OK except for the release bearing lugs which seem a bit short.

I kept the old 3.2 G50 flywheel and clutch so I could use it to cross-check the positioning of ring gear and release bearing on the new clutch and flywheel.

Ring gear is no problem. Using KTL's method in post #2 of this old thread, I will swap the old ring gear across to the new assembly with some 4mm thick spacers between the ring gear and pressure plate. The spacers will also provide clearance under the ring gear for the rivet heads that can be seen in the pic below.

Where things don't look correct are with the height of release bearing lugs. The underside of the lugs (where the fork pulls against) are 7mm too short on the new assembly compared to the original 3.2 G50 assembly.

Kevin - if you are out there - did you find the same thing?
If so, I guess it wasn't a problem?

Anyone else got any suggestions here? Maybe there is another release bearing part number that is about 7mm longer?

The result could be that I run out of clutch travel, but I won't know until I put it all together and drive it.
If a longer release bearing isn't available, another option may be to fit a 7mm spacer between the slave cylinder and bell housing to compensate for the different position of the release bearing lugs. (This assumes that the clutch fork pivots at its centre - I don't have it handy to check.)
Anyone tried this?

[billjam]

The level of activity on this site is amazing sometimes. Posted this late last night (Perth time) and at breakfast time it is on page three already!

Come on guys ... any ideas on this?

Thanks for your response on the other thread Kevin, but not quite what I was looking for, but useful info for adjustment if I get that far.

[billjam]

I have the following options (and I'd just LOVE some thoughts on this):

1. Find a G50 release bearing with 7mm longer lugs (anyone got details?).
2. Accept reduced stroke on slave cylinder and hope it will be OK.
3. Space slave cylinder away from housing to compensate for shorter lugs (my current preference).
4. Try and get back some adjustment at the pedal end to compensate.

This diagram might help visualise the problem.
I may well be over-thinking this problem, but I don't want to get as far as installing the engine to find out if it is OK or not.

[rsscotty]

I am assuming in the photos above on the pressure plates that you have clutch discs installed on both setups and the pressure plates are torqued down, since this affects the position of the pressure plate fingers. We have done the conversion using the G50/01 trans. and used the same setup you are using, 964 RS parts. We have done nothing with slave spacing and everything works great.

Not many people may be aware of the modifications needed to use the 964 setup and use the 964 starter. The centerline of the G50/01 starter mount is actually 2mm closer to the centerline of the engine compared to the 964 trans. housing G50/03or G50/05. So to make a 964 starter work with the 964 starter ring gear in the stock position, you need to make an oilite bronze bushing to install in the G50/01 housing. The existing hole in the bushing position is not round, so we have drilled and tapped the trans. housing to install a set screw to secure the bushing. Also we have ground about 1mm off of the root and the outside diameter of the starter gear. You may also need to grind flashing off of the area where the starter gear travels in the bellhousing. If this is not done, the starter will bind and the engine cranks slow. I guess this is an option to using the 3.2 starter that does not use the bushing that the 964 starter uses.

[billjam]

Thanks Scotty,

Yes, both assemblies are complete and torqued down with the release bearing "circlipped" in place.
It is comforting to hear that you have had no slave cylinder problems with this combination of parts - that is my main concern.

As far as ring gear and starter are concerned, I won't have to worry about misalignment there because I will be reusing the original 3.2 G50/01 box, starter and ring gear. The ring gear in the top pic will be swapped across to the new clutch and spaced so that it will be at exactly the same height as it currently sits on the 3.2 clutch.