title says it.

which is easiest way to have lsd? for swapping stock stuff that is. i want to junkyard one.

 

I have never done it, but I believe you can put the Miata Torsen in the NA diff housing. The easiest, however, would probabably be to get a turbo rear end and buy a custom driveshaft to mate to the NA tranny.

 

what about s5 n/a lsd. found complete diff at junkyard here. just wanted to know if that was the way to go. would that be drop in swap i guess is what i wanna know.

 

Yes, just verify that it has a functional lsd.

 

No

The easiest way is to swap in the S4 n/a clutch-type limited slip. Just swap the entire diff. Everything will work with your current setup. Done.

If you get a S5 GTUs(4.3), or S4 automatic(3.9) diff you will need the associated speedo gear off the tranny as your open diff is a 4.10.

The Miata TORSEN needs to be swapped into the n/a housing with the RX-7 ring gear; not exactly noob friendly.

 

Thanks Yani for correcting my misinformation. I forgot about the gearing on there.

 

The only S5 n/a rear end with LSD is the GTUs. Good luck getting a hold of one of those. All TII diffs have LSD and in my opinion is a better choice. IF you can drill new holes in the flange for the N/A shaft it will save you bit of trouble. But you will have to use TII axles with the diff.

Another thing to remember; S4 LSD's are clutch pack and S5's are viscous. S4 GXL, GTU,and TII models had the lsd (I think even the autos did). And Only GTUs and TII S5 models had LSD. All others are open diff. 3.90 (auto) 4.10 (TII and 5 speed N/A) and 4.30 (GTUs only) And LSD differentials will have a tag hanging off the backside of the pumpkin.

 

i love my gxl... theres a writeup on an lsd rebuild right?

 

The S5 lsd's are viscous, as was mentioned by flamin; which means odds are good it works as an open diff by now, since the silicone in a viscous sheers down over time, and can't be replaced. Better choices are an S4 na clutch-type, or the Miata Torsen swap - swapping the ring gear itself is not a big deal, but if you're not experienced, you should have someone setup the ring and pinion for you. The S4 na lsd, on the other hand, can simply be left in the pumpkin and swapped whole into the car. Be aware, though, clutch LSDs wear over time, and may need to be rebuilt by now - in which case, there's little to recommend S4 over Miata swap.

 

T

 

The FSM has everything you need.

 

Racerca and all,

Sorry for threadjacking, but since the q' has been answered, here I go:

Where can I get info on parts to rebuild an S4 LSD? What kind of $ are we talking?

Thanks!

 

You can rebuild the s4 clutch type with shims from a coke can. Money is, lube, coke can, and labor. There's a write up somewhere around here....

 

Someone found this thread, linked it and IT IS ARCHIVE WORTHY with PICTURES! Shows an LSD swap in a 1st gen., then ends up being a rebuild of an S4 diff.

Moderators, can we add this to the archive for us planning on rebuilding S4 clutch type LSD's?

https://www.rx7club.com/1st-generation-specific-1979-1985-18/my-85-rx7-non-turbo-lsd-rebuild-question-thread-815576/