Clutch confusion

[MerlynIIa]

6970I am in the process of building a "bitsa", made up of a 1974 Series III and a 1965 Series IIa. I am using an altogether different vehicles engine, that has a serial number indicating it was build around 1960-61. My question is this. I am using the IIa tranny, serial number 5249189C. the Series III tranny was frozen up and the IIa tranny is apparently good shape. I took it to a transmission shop for a check up and, after new gaskets and seals, it was declared in great shape. I purchased a 9" clutch disk and pressure plate off of Ebay (some of you may have recently seen the sale), as I understood that a 9" disk is appropriate for the 1965 IIa. I pulled the old clutch disk and pressure plate and the disk measured 9.5"! The pressure plate, to add to my confusion, is a Borg and Beck unit and list the size as 9/9.5". The tranny is different from the Series III tranny and has the slave cylinder on the right side. It has the old style clutch actuation mechanism also. Will the 9" work???

Second issue. the old pressure plate has an odd (to me) set up in the center, with a large bushing that is held in place by three straps. The large bush meets surface to surface with the "throw out bearing" type bush that is thrust forward by the clutch actuation mechanism. This is different looking than the pressure plate that I recently bought, which has no such bush and looks like the ones for sale listed for this vehicle. What is up with this unusual (to me) set up?

The IIa appears to have been set up for some heavy use. It had what appeared to be an original soft positrac type locker, Warn MII hubs, and home made winch bumper and early Warn 8200 winch. perhaps there was a heavy duty clutch option?? Any wisdom or information or advice appreciated. :) After a long time working on things, I am finally getting ready to install the tranny and then the engine. I dont want to mess this up!

[MerlynIIa]

To reply to my own thread, and probably showing massive amounts of ignorance, I had a possible idea. Perhaps a heavy duty clutch option was available that put a 9.5" clutch where a 9" clutch was standard. the set up in the middle, with the large bush, was an adapter to allow the larger unit to fit in the older style set up. I have probably just embarrassed myself with this theory, but guess I am willing to for the sake of my Rovers.

[SafeAirOne]

You can use either a 9 or 9 1/2 inch clutch setup so long as the pressure plate matches the friction disk. Series IIA clutch throw bearing contraptions require the type of pressure plate that has that odd piece in the middle, like in your pic. That's the first one I've seen with the straps though. Most just have that odd piece just sitting in there, IIRC. Nice, modern Series III clutch throwout bearings do not require that odd piece in the middle of their pressure plates.

[MerlynIIa]

So I can go ahead and use the 9" clutch and pressure plate then. Does our host sell the "odd piece"? I looked at clutch parts on line and did not see it and did not know what to call it to order one. I had thought a 9.5 clutch only came with later Transmissions that were full synchro. I think i had seen some post suggesting you had to change the bell housing and front shaft to use a 9.5. Thanks for your reply.

[SafeAirOne]

Does our host sell the "odd piece"? I looked at clutch parts on line and did not see it and did not know what to call it to order one. I had thought a 9.5 clutch only came with later Transmissions that were full synchro.

It doesn't require any different bellhousing or input. Just pick a 9 or 9.5 SIIA clutch. The odd piece is an integral part of the SIIA pressure plate.

[MerlynIIa]

"The odd piece is an integral part of the SIIA pressure plate. " posted by Mark, above

When looking at a IIa pressure plate from our host, it does not show the "odd piece". The pressure plate i bought is a bit different, but I have seen it also on a different site without the "odd piece" Here is Rover North's pic. http://www.roversnorth.com/p-17157-9-inch-clutch-pressure-plate.aspx The one I bought does not have the piece. I am confused.

[SafeAirOne]

Ahh. OK. You didn't say your new pressure plate was a Borg and Beck style pressure plate (as shown in the RN link) instead of the more common (nowadays) diaphragm style, like the one shown in the pic of your original. Just to confuse you, Borg and Beck also made diaphragm-type pressure plates, as in the pic or your old one.

I've never seen anyone re-install a new 9" clutch before, (everyone 'upgrades' to the more common 9.5") so the old 9" pressure plates are probably all B&B style and I suspect that since all of the 9.5s are diaphragm style they need that odd piece in the middle of the spring fingers to work on the IIA throw mechanisms.

Not sure if the Borg and Beck style needs something in the center for use with IIA transmissions or not--I don't have a IIA parts Catalogue. I doubt it does, but if noone with specific knowledge of this setup chimes in, I'd just give a quick call to our hosts. They'll be able to tell you pretty quickly.

Check out: this (http://www.competitionplus.com/03_25_2004/clutch_univ2.html) and this ("http://www.carcraft.com/techarticles/clutch_basics/) .

[Les Parker]

Attached are the pics. of the 9" and 9.5" Pressure plates.

Fully interchangeable, providing the flywheel is machined to suit and the corresponding friction plate is used.6975

The one on the left is the original style 9" the later 9.5" is shown on the right.

[MerlynIIa]

Thanks Les and Mark. I have the Three prong in the middle like the one on the left. I did not realize I could use a 9.5 inch disk or probably would have gone with that. However, since I now have a nice 9" one, i will go ahead and use it. Thanks for clearing up my confusion!