Rear Decode Help
Thread Starter
Pro
Joined: Sep 2007
Posts: 735
Likes: 1
From: Harleysville PA
Rear Decode Help
i pulled a posi rear out of a 75 and need help decoding to determine what gears it has - the codes on the maincase are OA2 W7E1 and 8899143. Anybody know what gears it came with? thanks for the help
also, how do i verify that the gear ration has not been changed?
also, how do i verify that the gear ration has not been changed?
Drifting
Joined: Oct 2007
Posts: 1,458
Likes: 1
From: Collinsville MS
St. Jude Donor '08
its been a long weekend so you may want to get some other input, but according to my Chevy parts and illustration book the OA identifies it as 3.08 out of a 76 or 77. The only true method to be sure is to count the teeth and do the math. Sorry not more help, I am just give out tonite.
Drifting
Joined: Oct 2007
Posts: 1,458
Likes: 1
From: Collinsville MS
St. Jude Donor '08
Count the number of teeth on the ring gear and divide it by the number of teeth on the pinion. I am reinstalling my rear this week and checked it against the stamp, it was correct 3.55 for mine. I dont know if I would trust the stamp if you are not the original owner as someone may have swapped it out before, or replaced the gears. Good luck
Original codes for 72-75:
LR, AX =3.36
AC = 4.11
AB = 3.70
AA = 3.55
AW = 3.08
AV = 2.73
76-77 codes:
OA = 3.08
LR, OD = 3.36
OB = 3.55
OC = 3.70
Original codes for 72-75:
LR, AX =3.36
AC = 4.11
AB = 3.70
AA = 3.55
AW = 3.08
AV = 2.73
76-77 codes:
OA = 3.08
LR, OD = 3.36
OB = 3.55
OC = 3.70
