This question has probabaly been asked before but I have really no clue what gears I have in my car. 1989 GTA. Posi and rear disk. I would guess it's 3.23's but I don't know. The RPO codes are missing so I can tell. Is there a way to find out besides pulling the cover off? Thank's
Phil
EDIT: I should also add that I want to change the gears at some point this summer. I went from a 245-50/16 to a 285-35/19 in the rear and I would like to get it geared lower than it was to begin with. Is there a way for me to figure out what gears would bring me back to stock with these new tires and then figure out how to get them lower than that? Thank's
Phil
EDIT: I should also add that I want to change the gears at some point this summer. I went from a 245-50/16 to a 285-35/19 in the rear and I would like to get it geared lower than it was to begin with. Is there a way for me to figure out what gears would bring me back to stock with these new tires and then figure out how to get them lower than that? Thank's
AlkyIROC
Moderator
close
Jun 5, 2026
Crawl under the car and look to see if you have a 9 bolt or a 10 bolt diff.
What engine? What transmission?
According to the TGO database, if your GTA has a 5.0 and a T5, you should have a 9 bolt with 3.45 gears. If you have a 5.7 with a 700R4, you should have a 9 bolt with 3.27 gears.
What engine? What transmission?
According to the TGO database, if your GTA has a 5.0 and a T5, you should have a 9 bolt with 3.45 gears. If you have a 5.7 with a 700R4, you should have a 9 bolt with 3.27 gears.