Strengthening 944 Transaxle

my research on the AOR indicated that its not the input shaft itself thats shot peened, its 1st and 2nd gear thats shot peened. the shot peening removes stress risers, doing it would make the teeth of the gears less prone to breaking. that being said, ive never seen pics or heard of anyone breaking 1st or 2nd gear in any 944 transaxle, the weak part seems to be the ring gear. the case is weak in the non turbo transaxles, excluding the s and s2 (aos and aot) as they are the same as the turbo transaxe aside from the final drive ratio. the problems with the case on these transaxles is actually the bearing support in the center, the pinion loads rear bearing and it breaks the casting, this is what the reinforcement plate is designed to stop. turbo transaxles (and aos/aot) didnt have this problem as they beefed up the casting.

imo, i dont think the aor is that much better than any other turbo box if your not considering the lsd or cooler. now adding those things in, the lsd in the aor is the strongest of any of the 944 transaxles. that being said, none of the diffs themselves are that weak, and you can mix and match the clutches to come up with more holding power on any of the diffs.

as for cryo treating, ive built a lot of transmissions and never done it, so its hard for me comment. a lot of people claim it does a lot. imo if your gonna strip it down to get the ring and pinion out and cry them, may as well strip the input shaft down to and send all the gears and shafts in.

just one more thing to add, as the turbo transaxles will take quite a bit of a beating, dont expect to be doing line lock burnouts all the time, you will kill it. no matter what we do with these transaxles we are still limited by the size of the parts inside, and they just dont take shock loads from 2-3x the torque than the cars came with.

i went back and re-read some info, one source says "the input shaft, 1st gear were shot peened for added strength". another source said "1st and 2nd gear are shot peened". so who knows exactly.

the plate is quite possibly redundant in the turbo transaxle, ive read info saying its not needed, others swear by it. i have an AOR going into my swap (its a little different, its a gm 2.2l ecotec, currently putting down 325 whp, next year ill be upping the boost to around 450 whp, and an ultimate goal is around 600). when i pull it apart im going to be putting the reinforcement plate in.