Gearbox swap series 2 into sIII

[Kjman55]

My sIII was originally a 2.6. It had a Holden 186 fitted at some stage, and it looks like a Johnstone conversion to suit the 6 cylinder bell housing.The gearbox was not working and I have pulled it down and found it is simply not worth repairing there is so little salvageable. The car came with a (spare)good series 2 box with a 4 cyl bell housing and a new (Roevers) series 3 diaphragm clutch ( pressure and driven plates) The flywheel has ""283"(I think) stamped on it so I assume it is from the small v8 which I understand allows a bolt on series 3 clutch pressure plate. The clutch fits it.
I suspect a bad misalignment was the cause and am pulling the engine out this weekend to sort out that aspect.
Here is my question...what is involved in fitting the series 2 gearbox into a s3?
I know I will have to change the bell housing and I have cleaned up a s2 6 cyl bell housing and throw out assembly ready to bolt on.
I have also got s2 the slave cylinder ( new PBR) and the series 2 slave brackets etc. I know I will have to reroute the hydraulic line to the other side for the series 2 slave.
Specific questions...
Is there a clutch plate I can use with the series 2 box that will bolt onto the Holden flywheel without re drilling it?
Would the diaphragm series 3 clutch be compatible with the s2 throw out bearing arrangement?
Has anyone done this before, and if so I would appreciate any pointers.
Cheers,
Keith

[JDNSW]

The easiest way to change is to fit the front of the gearbox to a Series 3 one. This is possible if it is a late Series 2a box with the same size layshaft as the Series 3. That way the clutch mechanism can be left the same as it is.

More and more evidence seems to be emerging that Holden engine adapters have been an issue with alignment, and you need to very carefully check the alignment when installing the gearbox, modifying the adapter as necessary.

John

[mick88]

Keith,
firstly when you mention the small V8 are you referring to a Holden or Rover engine. Do you mean the small Holden V8, in that case it is a 253, however I am not sure if they had a larger diameter, or heavier flywheel, than the six cylinder engines.
A Holden flywheel is about 5mm in overall diameter short of taking the 9.5" Land Rover pressure plate. The bolts to hold the pressure plate on will be right on the edge (just inside). However you can shrink a metal band on the outer circumference (similar to a ring gear) to overcome this.
A Holden (six) flywheel measures approx. 280mm dia and a Land Rover two and quarter is approx. 285mm dia.
So if the flywheel you have measures around the 285 mark across the face you are in luck.
Another good idea when you have it all apart is to get a steel bush turned up to fit into the centre of the flywheel so that you can use a standard Land Rover spigot bush, rather than a modified bush specific to the conversion, which fits into the rear of the crankshaft.


Good luck.
Cheers, Mick.

[Kjman55]

Thanks John. Unfortunately it is the older a 2 box with the series 1 type big front lay shaft bearing.
Thanks Mick. I double checked the flywheel...looks like it says 253 not 283 as I thought so probably the small Holden v8 flywheel. I read somewhere on the web ( can't find it again now!) the 253 flywheel fit the 6 Cyl crank ( 6 bolts) and that a Land Rover compatible clutch bolts on. It's a 9.5 inch clutch ( suits the s3 box). I am wondering if I can simply bolt the s2 box onto this clutch...the s2 original clutch had 3 "fingers" around the centre to engage with the throw out bearing while the s3 clutch uses a diaphragm type with about 10 or so ( I haven't counted them) much lighter " fingers".
Keith

[mick88]

Sorry Keith,
I don't know the answer to your clutch question.
Hopefully someone on here will be able to help you.
If it is not too much trouble could you post a couple of pics of the 253 flywheel and also weigh it please.

Cheers, Mick.

[JDNSW]

The 9.5" clutch was optional on the 2a, but the pressure plate is different. It is still a diaphragm clutch, but has a spacer on it to fill the gap between the release sleeve and the diaphragm fingers. P/N GCC112 for all engines.

John

[Kjman55]

Thanks John. So if I can get the "pad" [GCC112] that is presumably pressed (?) onto the diaphragm fingers, the s2 box should bolt on ( hopefully). I am on a steep learning curve here, and I owe many thanks to all who have responded.
I will post some pix of the flywheel as requested by Mick over the weekend. Will,weigh it when I get a chance ( still fitted to engine) but a Google search suggests around 13 kg

[JDNSW]

The "pad" is not separate, it is part of the pressure plate (or "cover" in Landrover speak), so you need the new pressure plate.

John