Alright.. so this has probably already been answered more than once but I didn't really look for very long. So the question is, does the N/A S4 LSD fit into the N/A S5? Any help on this will be much appreciated. Thanks.

Yes. As long as they're both n/a, it'll fit.

i believe that even a turbo diff should fit also but you need to change the shafts

I don't believe this is true. The turbo LSD is bigger, and won't fit in the pumpkin. You have to replace the differential housing with a turbo one. Also I believe the driveshaft and halfshafts have to be replaced. And if you replace the driveshaft then you also have to replace the transmission since the yoke won't fit. I think you can redrill the driveshaft though to make it bolt up...



*I think*



What I'm doing with my 89 n/a this weekend is putting a miata LSD in. It has to be from a 94+ miata. As far as I've read it's a direct swap.

I can't remember if I stated this before. But my 91 GXL has the TII swap done to it already with the S5 motor and tranny. I have the custom drive shaft from Mazdatrix for the TII to N/A rear end. So the only thing keeping me from buying it is if the S4 rear end is the same as the S5 rear end.

'86 to '88 LSD will fit into the '89 to '91. Depending on what you use the car for, you can actually view the S4 LSD as an upgrade since it's mechanical and not viscous.



Mechanical LSD will transfer torque better and provide better driver feedback (sometimes for the worse). A lot of drivers in drift, auto-x or time trials will take the mechanical version over the viscous just to get that feedback (and they're cheaper, lol).



A T2 LSD is bigger as stated before. You can swap in the entire pumpkin, halfshafts, driveshaft and tranny - but only the entire equation, not just part of it.



The redrilling of the flange works - but is HIGHLY not recommended due to safety. It leaves very little metal for the bolts to dig into and can easily break sending a driveshaft into the passenger compartment which at 6K RPM is going to be a bad day!

If you're putting an NA LSD into an NA rear end, you should be fine.

if you have a turbo engine and transmission why dont you put a turbo rear in the car?



why bother swapping NA diffs?

So in other words, you're saying that I can get a direct swap with the S4 LSD to change out my S5 N/A shaft since I already have the TII tranny and the Mazdatrix driveshaft makes up for the gap?

you still need the mazdatrix driveshaft as long as you stay with a NA rear end regardless if its s4 or s5.



if you go with a turbo rear you need the correct tii driveshaft, and of course halfshafts.