Searched to no avail. Will a differential from a 85 GSL-SE fit in my 83 GSL. I know there was a change in rearend sizes between 82,83 and 83.

 

i think it will bolt right in.

 

No, you have the early "small" axle (79-83); not the latter "big" axle (84-85). Unless you want to rebuild the LSD with the smaller side gears (available from Mazda, but over $100), you need to find a 81-83 LSD unit. The only change from 82 to 83 was the transition to the larger companion flange, which continued through 85 (same driveshaft 83-85).

 

so if i get a 82 rear pumkin then I'd need to get a 82 drive shaft also? This is becoming such a pain in the ***. I still don't know what the noise from my rear end is. I'm just guessing its the ring and pinnion. I thought it was the lower links, but when i took then off i found it wasn't cracked that it was just undercoating making it looked cracked.
I hate cars.... I'm gonna buy a Honda civic so i never have to touch my car again..

 

Not to mention that the SE diff has one clutch plate versus the GSL's two... Or so I'm led to believe... Lemmie dig up the thread. Someone more reputable than me said it.

EDIT: https://www.rx7club.com/1st-generation-specific-1979-1985-18/gsl-vs-gsl-se-lsd-346525/

 

Even if that's true (never noticed it, myself), it makes no practical difference. The unit will bolt into any axle-matching setup and work just fine.

Yes, if you go with an earlier pumpkin, the driveshaft would also need to be swapped...or, you can just swap the companion flange if you're up to it. Personally, I think it's easier to just swap driveshafts. Anyway, welcome to the 83 nether-year syndrome. Honestly, I like the '83s best of all the years. Still has the stronger axle housing (despite the smaller axles, it's the housing that prevents axles from breaking!), the 79-83 interior (which I highly prefer over the later stuff), bolting in the later "big" axle units (e.g. GSL-SE, with bigger brakes) is a snap because you don't need a new driveshaft, it has a 130 mph speedo, etc. I've owned at least three '83s that I recall (plus a '79, 82, and a pair of '85 GSL-SEs).

 

arrrrgggg i don't want to have to spend money I don't have! expecially if the noise isn't from my diff. arg!!!

 

How big of a hurry are you in? I think I may have a 79-82 driveshaft down at the shop in Portland. Yours free, if I can find it. I'm going down next weekend and could see if I can dig it up, but no promises. I have so much crap, it's hard to keep track of it all. Frankly, I'm thinking it might have gone in the scrap metal bin...

 

if the 3rd member driveshaft flanges match up then yes, you can swap them

 

That's not entirely true, as I already stated. The '83 year was a 'tweener with the latter style flange and the older, small axles.

 

I think 680 has a point. If you get an 82 (or earlier) diff, then you can take the drive shaft flange from your 83 and swap it with the 82 diff. You will not need another drive shaft.

On another note, I would isolate the noise before you swap the diff. First gens seem to eat the axle bearings and they make quite a bit of noise when they go bad.

 

Will the SE ring and pinion fit into a earlier pumpkin?

 

ring and pinion fit no problem.

 

Sweet, I'm gonna do it just for something to do, lol. I know where one is sitting, It just never occured to me that it would fit since everything else doesn't.