is the spiget bering the same size for a
manul gear box as it is for an auto

no, a series autos dont use a spigot bush or bearing. Reason being, the torque converter is bolted to the flex plate. ( the auto input shaft doesnt touch the crank. )

so if i take the fly wheel ect from my manul a12
ant fit it to my a14 motor which was previosly fitted with an auto will i need to fit a spiget bering to the end of the crank or will the shaft just slide steight in

If you plan to run a manual box you need a spigot bush. ( still avaliable at nissan ) Otherwise the input shaft will slap around in the crank.
The cranks are all the same - So you just need the bush and it will fit

no worrys thats what i thaught just whanted to be sure
i am going to put my a14 in the green machine as i am sick of the a12 already.
I was going to work it first but i cant wait that long so i will have to find another one to do the work to, maby an a15 this time

THERE ARE manual AND auto spiggot bushes on A series motors, my farm hack 120Y "The Defect" has both!

everone scratches their head!?

simple "The Defect" was an auto, and recently had a manual conversion, but when the flywheel was put up to the back of the A12 the flyweel was a small spiggot and the A12 was a large spiggot which was remedied by machining the flywheel to the large spiggot

the flywheel was also machined to fit over the auto spiggot bush, to prevent the flywheel "going on holiday, via leg"

I am sure the part you are refering to, is in the centre of the flex plate pictured below. And you should have simply removed it from the end of the crank and your flywheel would have gone straight on without any machining. I am also sure that with this part left in place you will not be getting full clamping force on your clutch plate since the clutch is now further inside the bellhousing and the throwout bearing would have started to engage the pressure plate fingers as you bolted the gearbox up to the engine.

Part number "32202 - 18000 Bushing - pilot" is the spigot bush that goes into the hole bored in the back of the crankshaft to support the foward end [or spigot] of the gearbox input shaft /primary shaft / first motion shaft or "assembly - gear, main drive" [pick one]

The standard flywheel will fit directly over the auto crankshaft once the "12330 - 20300 pilot - converter" is removed from the back of the crank. This piece has a lip that goes over the seal surface of the crank & it provides a larger diameter face for the relatively thin "assembly, drive plate & gear" [flex plate] to mount against. Next is in turn is the "plate - crank converter" which is simply a disc that goes on the rear face of the flex plate. The bolts then pass through all three elements & hold all of these tight to the crank, so the flex plate does not actually touch the crank or the mounting bolts.

It sounds like someone should have looked a little closer when converting from auto to manual.

So lets get it steight, the spiget bering is the small brass bush that fits inside the back of the crank. It's not fitted to auto trans models as it's not needed, however, buying one as a spare part & fitting it will convert the crank to a manual trans compatible one.

By removing the three elements of the flex plate from the crank, you will be able to fit a standard flywheel straight to the crank. Be sure to use the correct flywheel bolts as the ones for the flex plate are diferent.

Couldn't be easier.

I t never occured to me that part was on the end of the crank... Someone should have written an auto to Manual coversion article and I would have found the correct info, then again asking dad if he could "machine a few thou off the back of the flywheel might have been a good thing...

but "The Defect" is back together again, and I have only had one chance to have a drive of it, it seems fine the clutch works correctly, and "The Defect" seems more powerful- almost TOO powerful I shouldn't have lightened it off so much as a auto!

"The Defect" doesn't get driven much anyway so it should last a while anyway

I am hoping to get another 120Y complete less motor and gearbox, and I hope to have an A14 or A15 in that one...

I have Definitely learnt that there isn't 2 crank spiggot sizes but there is a machined piece on the end of the crank on auto A12's.

however with the flywheel/clutch issues Phunk...

"sooner or later... Time will tell"