I may need to get a rear end and figured I may as well go with LSD in my vert. Will any year/model LSD fit?

 

S4 TII diff's come with clutch type lsd, which is torque sensitive.

S5 TII came with viscous {sp?} type lsd, which is speed sensitive.

FD's came with torsen and can fit in either or housings of the TII's.

same goes for n/a of each year. But n/a have a 7" casing while TII's have 8" (obviously you cannot mix up the two.)

Personally I like the S4 clutch type lsd better.

For the axles, you need it for whatever year you buy the rear end for.

 

ALOT of good information. how ever, to the OP get an s4 GXL diff. The 5 speed's will have a 4.1:1 LSD, and the auto's will have a 3.909:1. i have the 3.909 on mine. Only the GXL's will swap without modifcation, you could use a turbo diff, but you'll need to drill the shaft or flange for the n/a shaft to meet the turbo DIFF.

take your pic, it's a direct swap for s4 or s5 verts( which you did not indicate).

 

Drill the flange. There's more meat on the flange than on the driveshaft, unless you have a turbo car and are using an n/a diff.


As far as fc's go, they came from the factory with all kinds of diffs regardless of trim.

However, the clutch types are s4 and the viscous are s5. The cars from the factory did not have those mixed between the generations.

Gearing also varies. I was under the impresson that all n/a open diffs have 3.90. The n/a lsd's are coupled with 4.10 units and the turbos and gtu's had 4.30. Maybe fd's also but dont quote me on that.

 

I would never quote someone, THAT far off .
only the GTUS has a 4.3. all else had a 4.1, unless it was an auto, you got a 3.909, but verts( even auto verts) got the 4.1.(i've been told, yet to be confirmed)

RX-7 Stock Rear Axle Ratios
Year / Model Ratio
79-82 3.909
83-84 12A 3.933
84-85 13B GSLSE 4.076
85 12A 3.909
86-88 5-spd All 4.10
86-88 Automatic 3.909
89-92 Turbo 4.10
89-92 non-turbo, non LSD 4.10
89-90 non-turbo, viscous LSD, "GTUs" only 4.30
93-95 w/manual trans 4.10
93-95 w/automatic trans 3.909

http://mazdatrix.com/g5.htm


EDIT=I'll also give you some personal experiance with an S4 N/a LSD, after multiple abusive clutch drops, doing donoughts, and slidin, and 6k rpm clutch drops at the drag strip, the WEAKling N/a transmission blew first gear apart before i had a breakage in the diff, infact, it held up for another 8k miles in another car before i sold it. this was at about 170HP. even the N/a diff's in my opinion pretty tuff.

 

Thanks guys.

Now I will have to hunt down the one I want. :p

 

I have an 88 GXL N/A to my understanding it has the LSD. Is the Turbo 2's of the same year stronger i mean can they handle more power/torque?

 

infini 4s from japan came with torsen diffs and 4.3 rear ends i heard...

 

I know this is true but confused about my car. Its a 86 n/a with a T2 rear end but has 4 lug. (I bought the car with a entire T2 swap besides the 4 lug, I have the t2 driveshaft from the car and a n/a driveshaft.

I know its a T2 rear because i had to cut slits into my n/a driveshaft to make it mate to the diff. "It has a n/a engine now""" (I have a T2 driveshaft laying around and that mates fine, but wont go into my n/a trans)

I went to do my rear 5 lug swap today, using s4 gxl lower control arm, axle, hub, ect. Everything mated fine and noticed my old 4 lug had n/a axles like my 5 lug swap.

===HOW THE HECK IS THE DIFF/DRIVESHAFT FLANGE T2 BUT THE HALF SHAFT FLANGE IS N/A??

Sorry for the small thread jack...DOH!

 

^^
Because the spline count on the rear wheel hub is the same as N/a to TII. What differs from 4 lug and 5 lug, is obvious braking system and 4 lug. But other then that no difference.

What the difference between n/a and tii axles are lengths. Since the TII case is bigger, the axle will be shorter, then a n/a.

 

I know that's the same.

But how is it that my n/a axles mate to the t2 diff without any modification unlike my driveshaft? Is it possible the previous owners put in the n/a stub shafts into the t2 diff? Are those the same spline count?

 

If you are looking for used differentials, keep in mind that most of them are toast by now, or soon will be. It costs about $800 in parts to rebuild an S4 differential, and S5 differentials are not rebuildable.

Most racers either use the S4 LSD or an aftermarket racing LSD (Kaaz, Quaife, etc.). The stock open differential is just fine for street and autocross use.

The wheel bolt pattern is based on the hub, not the spline.

NA and TII axles have a slightly different bolt pattern. NA axles will not mate to the T2 differential without modification. Your car probably has T2 axles. If not, then somebody probably ghetto-rigged NA axles to fit, which is possibly a dangerous condition. Since you have already created a dangerous situation by slitting your driveshaft to fit, then there isn't much point in worrying about the axles.

You can check your axles if you have calipers (dimensions are approximate):
T2: 26.35mm shaft diameter / 88.51mm outer race housing diameter
NA: 24.20mm shaft diameter / 82.04mm outer race housing diameter

 

I took the old axles off when doing the 5 lug swap. I swapped the entire axle, hub, control arm, ect.

The old axles were the same size as the other ones i put on. I guess they were both n/a axles. But strange how they both mated to the diff no problem but yet my n/a drive shaft needed to be modified to fit the diff. (had to cut the driveshaft holes outward)

I guess this is a frankenstein rear without showing signs of modification or some crap. I'd like to add the ghetto driveshaft wont be on much long since im doing a t2 swap in under a month. Thanks for the info thought.