As title, is a box spacer needed and if so how wide does it need to be?
and i could do with answers for a single plate and twin plate clutches...

David.

 

Just curious. Why a f23?

 

Well I know the f23 uses different bolt pattern than the 35/lsj for the flywheel.

 

Shorter gears, rebuildable

 

Yeah shorter gears, its for drag racing and F23's in england are 10 a penny so if it breaks then its no worry.

David.

 

everyone says it wont work, however myself, im not sure why. i know the f23 will physically bolt up to the lsj, and i do know the f23 clutch wont bolt to an lsj. everyone also says the lsj clutch wont work with an f23 but dont give a reason why. when i did the clutch in my car i used the alignment tool i have for my old cavalier, so i know the input shaft and spline diameter is the same between the f23 and f35 (as well as the old cavalier isuzu 5 speed, getrag 282 in v6 j-body, and muncie 4 speed in the real early j-body/fiero). knowing that, the only thing i could think of why an f23 wont work on an lsj using an lsj clutch would be the slave cylinder. you would have to use an f23 slave cylinder, really the only thing different would be the height from the bellhousing to slave mounting surface and the throw of the slave cylinder.

what it comes down to is it seems everyone is guessing it wont work without any reason, aside from thats what they have read. would be interesting to see somebody try and show why it doesnt work.

 

from what i know it has to do with spline count, not diameter.

 

I will be swapping to an f23 on my turbo swapped 06 ss/sc this winter. I may come up with a how to. I run a f23 in my brothers 500+ hp cavalier. Only thing the transmission has done to it is a modified OBX LSD. The cav get driven HARD and never misses a beat!

Things you need
-You can use the lsj clutch/flywheel, you will need the trans spacer
-f23 axles
-f23 shift cables
-f23 front trans mount
-Modified lsj thermostat housing to clear the shifter cables
-f23 line from the clutch master cylinder to the f23 slave
-f23 slave cylinder

I think thats it. I Have a couple new f23's waiting for the OBX diff. I will be swapping the f35 out of my car to my brothers car 2.4 ss, thats where I am getting all my swap parts.

The swap has been done before, just never documented. (I will document mine when I do it in a month or so). I am building a couple OBX diff's for some guys on j-body.org. I will have a how to on that as well.

 

thats some good info there, do you know how thick the box spacer needs to be?
I look forward to a "how to" on the box conversion.

Thanks, David.

 

I'm pretty sure lsj flywheel is 8 bolts and f23 is 6. Zzp figured it out because the f23 stage clutches they sell are same just use custom flywheel with 6 bolt I'm almost certain.

 

yes its a known fact that the 2.0l crank uses an 8 bolt flywheel and the 2.2/2.4 crank uses a 6 bolt flywheel. this is the reason most say you cannot swap the transmissions. however really what it comes down to is using an lsj clutch with the swap. it seems that it will work, but without actually doing it, its hard to know if it will or wont work.

 

The lsj clutch/flywheel set up is a little bit thicker than the l61/le5 clutch/flywheel set up.

If you are using a lsj bottom end you need the trans spacer so the pressure plate will clear the trans case, no matter what trans you are using.

If you are using a l61/le5 bottom you dont need the trans spacer for either transmission.

The swap has been done before on here and on j-body so it is possible.