I know..........LSD........HAHA. Ok. On to the serious issue. I have a 80 SA I just brought back from the dead yesterday. Well, I've spent the last week transpalnting a 81 12A from a donor, and I decided to use my RB intake, Holley carb, and RB header. I have a rear end that came out of my 83 GSL that I replaced with a 84 SE. The right side axle is bent in the GSL rear end. I have heard that the small axles are the same in the disk or drum rear ends. The only differance is the brake backing plates. So, can I use the axle out of the drum rear in the disk rear? If it will not work, then can I use the LSD out of the disk rear in the drum rear? I really don't care about using the disk rear in the SA because I would need the right park brake cables, and the proportioning valve. I guess the main question is about using the LSD in the SA rear end. Thanks guys. Sam.

 

You can swap the diff and be on your way. Leave the pinion nut alone and you will be fine.

 

Sweet. Dude, you are on the roll. I always fell safer hearing your responce first. Thanks trochoid!

 

rock on with that, let me know how it goes!

 

Keep in mind that the big/small axle still applies during the swap. They must be the same.

 

Now that You mention amall axles, If not from an Rx-7,(we didnt get LSD overhere untill the big axles) which car will have a LSD diff that fits the small axles on my car?

Thanks

 

Just an FYI, I put in a GSL rear disk from an 85 in my SA and kept the SA proportioning vale and it works great.
But if you use a 83 LSD it will fit in all 79-83 axles. And if your using a 84-85 it will only fit the 84-85.
I say just swap the LSD in as the rear disk is not that much of an upgrade. Just easier to replace brakes later.

 

use a gsl rear end from a 81, 82 or early 83 to get an lsd that fits the small axle cars

 

The 83 disk rear I have is the small axle rear end. The SA axles are the same right? I am just scavenging parts that I already have to keep from putting a wad in this SA. I still have to pick up the Turbo FB from the painter this week. The SA was never supposed to be ressurected. It was just dumb luck running across an engine and trans. I gave $100 for the car. $150 for the drive train. $90 for the RB intake. $50 for the RB header. $50 for the Holley. About another $100 in misc. parts. Pissing of the neighbors taking the car down the street and back with only a header................priceless!

 

[QUOTE=bad 83]The 83 disk rear I have is the small axle rear end. The SA axles are the same right? QUOTE]


how do you know its a small axle rear end?

axles from 79 to early 83 are the same size(small axle)
late 83, 84,85 are the same axle size(big axle)

 

The bearings told me so.

 

Classic. ^

 

Also, the small axles have 24 teeth and the big ones have 26 teeth.

I'm about to do this swap with an '83 LSD into an 82 S.

 

[QUOTE=680RWHP12A;6842895]How would someone know if their 1983 RX7 is a early or late, for axel size?

 

don't know if there is a way to tell other than taking things apart to see/measure. really would have to know where in the born date, sticker on the door, this change took place.

 

[QUOTE=82GS-383;12547375]there is no such thing, people get confused about 83 because its not the same as 79-82 or 84-85
79-82 is a small driveshaft flange, small axle
84-85 is a big drive shaft flange, and big axle
83 is the big driveshaft flange but small axle

 

[QUOTE=j9fd3s;12547380]That's what I thought, but I figured it wouldn't hurt to ask.