what FC's have a clutch type diff.
 

I would like to know what FC's have the a clutch type diff because I found a parts car in a junkyard that has an LSD in it but can not find out what years had the clutch type diff. The car in question is an 87 GXL, four piston fronts and vented single piston with vented rear rotors in back. it has an automatic transmission if that makes a diffrence.

That's a clutch type.

86,87,88 are clutch type. information is in the FC3S faq thread in the specifications.

http://rotarycarclub.com/showpost.ph...27&postcount=4

Spin the tires...
If they both spin in the same direction, there's a diff on it.
Any 1986 - 1988 model that does this should have a clutch-type if it's still from the factory.


-Ted

Careful though, the diff might be worn out and in need of a rebuild in which case the rotation may not happen (i've messed with a few diffs that did that)... Speaking of which, i'll need to rebuild mine soon... :/

ok thanks for the info. but I would like to know if I where to put that rear end in my car would it be better or worse? I have an 88 SE with manual trans that has a 4.10 rear end and a open diff or the LSD which has the 3.90 in it.

i would keep the 4.10, remvoe the LSD from the 3.90 and install with the 4.10 ring. There is no messing around with pinion (which is the hard part of rear ends.).

why is that?

well you'll find that the car is slower with the 3.90 gears, but if taking the diff. assembly out and pulling just the differential and ring is not too difficult. Then you can replace the open diff. with LSD diff by just unbolting the 3.90 ring from the LSD unit and attaching the 4.10 ring to it. Then replace the LSD / 4.10 into the diff. assembly w/ pinion with the 4.10

ok thanks for the help and will be going to go pick up the diff soon, assuming that it is still in good condition.

The 3.90 gears are only in the convertible, and I think only automatics, but they all have LSD. This is one reason they are the SLOWEST RX-7.

All coupes (except the GTUs with 4.33's) have 4.10's.