I spent all last night searching the forums...Can I swap the guts out of an open diff with a brand new ring & pinion and aftermarket lsd? I am aware finding a used rear with discs and lsd is not too difficult. Thanks!

 

Yes, you can use the lsd center in you existing pumpkin and retain your existing ring and pinion (at least that's what I think you are asking). The main differences are big vs small axle splines (79-83 is small, 84-85 is big).

Isaac

 

Sounds more like he has an open diff to me and just wants to swap the guts of the pumpkin to convert to an lsd without pulling the pumpkin. I dont know enough to offer up anything on the subject, but I'd love to be able to do this myself.

 

Thanks fellas, Jingkun is guessing correctly, it wasn't a very clear question. I want to retain my open rear pumpkin and simply place an lsd unit inside, i.e. Kaaz, quaife, oem, etc. I know the splines in my SA22 are smaller but I will not be making anymore than 180whp.

 

The answer is yes, good luck finding an aftermarket LSD for the small axle though. Only 83 gsl's have small axle stock lsd's.

 

If it has an LSD, it's not an open diff anymore. I haven't heard of any current aftermarket company making an LSD that will fit the small axles.

81-83 GSL trim level models have small axle LSDs.

 

Okay, I did a bit of web surfing... It seems true that your best option with an SA22 is to obtain an 84-85 trans and diff. Everything is a bit more bullet proof. I found only one drop in LSD unit for 79 - 83 rear diffs and it comes from Australia: gurumotorsports AKA Rotorsports. The way I figure it, these things are getting old and doing a GSL swap is changing old for more old. As long as your plans for horsepower are modest the Rotorsport LSD for 700.00 w/o shipping is not a terrible option. I read that most Aussie first gens never came with LSD so it makes sense they make a product to fit the earlier models.

 

UPDATE: Received an email from Rotorsports. Guru Motorsports is now xtremerotaries and they list the pre 83' LSD on the website but it also says on back order. Also, it is double the price now. So the lesson here is: find a gsl rear end and hope it was taken care of by last owner

 

bullet proof? not very much so, more of a .177 air gun proof vs and .22LR proof when it comes to the world of solid axles ...i,ve already found, much to my dismay that pre-'84 axles have jack **** for aftermarket support, while the '84+ diff "shares" internals to the 4.88 R&P of the Kia Sportage, the 4.44 diff of the 4 banger mazda B-series pickups, the LSD units of the non-turbo FC's, as well as the whole 3rd member of the NA, NB and even the NC miatas...talk about us series 1 and 2 owners getting shafted in the long run

 

dude it's already been said but yes .... I am running a S2 pumkin in my S1 axle on my SA ... looks correct as I have my drum brakes until my big happy feet result in two marks on the road lol

 

I never have owned an SA until recently (two 1984's) - looking at a gsl shell for the drivetrain this week

 

cool another local SA ... color?

 

Some info on axle sizes

Solomiata : Drivetrain : Interchange

differential shaft diameters and splines:
7" small axle = 25mm x 24 spline (808, RX-3, 79-83 RX-7)
7" large axle = 27mm x 26 spline
7" S2000 = 29mm x 28 spline
7.5" small axle = 27mm x 26 spline '84-03 B2000/B2200 & early 95-97 Sportage
7.5" large axle = 29mm x 28 spline ('98-05 Sportage)
8" = 31mm x 30 spline. TT/TII/929

With a little bit of luck it's possible to pickup a 7" miata torsen for a few hundred bucks. Sometimes they pop up on ebay, i've seen them sell pretty cheap at maztoy.com also.