Rearend Problems
 

sorry to keep starting so many new threads, but once again i searched on this, but didn't have what i was looking for. i have an 84 rx 7 and the rear end is stripped out. does any know what years are interchangeable? we got a rear end out of an older rx but it was a little wider and the axels and where the drive shaft bolts up were smaller, if someone could help me out i would really appreciate it.

thanks.

does anyone know?

a 79-80 rear end has a smaller pinion yoke/bolt pattern than the 81-85, but other than that, they are identical (i just put an 85 rear in my 80) (except for the gsl-se ones, which have revised control arm mounting points)

you can change the pinion yoke so you can use your current driveshaft, cause i did that too. :bigthumb:

i have no idea 'bout rx2/3/4 rear ends, but all 79-85 are interchangeable with a little work.

Actually, the driveshaft/companion flange changed in '83, so '79-82s are the "small flange" ones and the 83-85s are the "big flange" ones. The axle diameter changed in '84, so '79-83 are "small axle" and 84-85 are "big axle" (ironically, the "small axles" are stonger because of the beefier housing). The axle size is not really important unless you are swapping, say, an LSD or replacing axles. The flange size is also not such a big deal because you can just swap driveshafts or the companion flange. There were also disc brake (GSL, GSL-SE) and drum brake rear end options. In those cases where you are going from drum to disc brake rear ends, you need the e-brake cables that go from the calipers to the clevis/pin union just inside the frame rail. A lot of work, but no real stumbling blocks. All the rear ends are the same widths and essentially interchangable. Early (79 only, I think) may have an odd brake line pitch.

79-80 have the 1.25mm pitch instead of the FB 1.00mm pitch.

what a whore of a problem that posed for me.

i just assumed the pinion thing was SA/FB, cause there's tons of different crap between them, and it all bites me in the ass when i work on my SA :(

so if i get a rear end out of an 82, it will work?

let me rephrase that, will the axle out of an 82 be the exact same as the 84? sorry

nevermind, i read where blake said it.

ok, this is my last question, so it will be ok to take a rear end out of an older 7 and put in my 84?

Yes. Ideally, you would get one from 83-85, so you have the simplest swap. If you get one from an 81-82, then you also need a 79-82 driveshaft (matching flange). If you get a 79-80 rear, then, in addition to the driveshaft, you have the issue of brake fitting compatibility (different thread pitch), so try not to go there.

we got the rearend in, all we had to change was where the driveshaft bolts to it. other than that, it fit in fine. thanks for the info.