I have a 1969 with 350/350 and 4 speed (M20). Can't make out most of the differential numbers, I believe it is a 3.36. Does anyone know how to tell if positraction without disassembly or buring the tires??
Thanks in advance for any info.
Place a paint/chock mark on drive shaft. Place a second mark on the top of your rear tire. Rotate the rear tire one complete revolution. The number of time the driveshaft went around in that one turn of the tire is your "gear number." For example, if you turned the tire once and the drive shaft went aroud approx. three times and a third ... you probably have a 3.36. Very careful when you do this and have the motor OFF !!!
PS... up on jack stands ... if both rear wheels turn ... it's posi
Given that of the 38,762 '69s produced only 36,965 had Positraction... Odds are yours has it.
If your true question is, "How can I tell what gear ratio my '69 has?", you can jack it up and mark the drive shaft and tires, rotate the tires counting the... etc. or you can sqiggle your way under it and look for the code stamped into the bottom facing portion of the flange of the gear case (assuming of course that no one has stuffed your case with different gearing than the factory setup):
Small blocks: AK - 3.36 AL - 3.08 AM - 3.36 AN - 3.55 AO - 3.70 AP - 4.11 AS - 3.70
For those with big blocks who come across this message in the ~future ~: AT - 3.08 AU - 3.36 AV - 3.08 AW - 3.08 AY - 2.73 AZ - 3.55 FA - 3.70 FB - 4.11 FC - 4.56
If you have a very late production '69, you share the '70 rear axle codes: SB: CAL - 3.08 CAM - 3.36 CAN - 3.55 CAO - 3.70 CAP - 4.11 CAS - 3.70 BB: CAT - 3.08 CAU - 3.36 CAV - 3.08 CAW - 3.08 CAX - 3.36 CAY - 2.73 CAZ - 3.55 CFA - 3.70 CFB - 4.11 CFC - 4.56 CLR - 3.36
Here's waving to ya - \||||
Owen ___
'67BB & '72BB ___
"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger
Given that of the 38,762 '69s produced only 36,965 had Positraction... Odds are yours has it.
If your true question is, "How can I tell what gear ratio my '69 has?", you can jack it up and mark the drive shaft and tires, rotate the tires counting the... etc. or you can sqiggle your way under it and look for the code stamped into the bottom facing portion of the flange of the gear case (assuming of course that no one has stuffed your case with different gearing than the factory setup):
Small blocks: AK - 3.36 AL - 3.08 AM - 3.36 AN - 3.55 AO - 3.70 AP - 4.11 AS - 3.70
For those with big blocks who come across this message in the ~future ~: AT - 3.08 AU - 3.36 AV - 3.08 AW - 3.08 AY - 2.73 AZ - 3.55 FA - 3.70 FB - 4.11 FC - 4.56
If you have a very late production '69, you share the '70 rear axle codes: SB: CAL - 3.08 CAM - 3.36 CAN - 3.55 CAO - 3.70 CAP - 4.11 CAS - 3.70 BB: CAT - 3.08 CAU - 3.36 CAV - 3.08 CAW - 3.08 CAX - 3.36 CAY - 2.73 CAZ - 3.55 CFA - 3.70 CFB - 4.11 CFC - 4.56 CLR - 3.36
Here's waving to ya - \||||
Owen ___
'67BB & '72BB ___
"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger
Use caution here, if you are supporting the car at the frame then the A arms will fall to their lowest position cause they are hanging in mid-air. This will put the axle universal joints at extreme angles and can damage them if the drive train is rotated with the engine. But if the diff. has a limited slip assembly in it when you jack both rear tires off the ground, leave the trans in park if its auto, in 1st or reverse if manual, engine off, parking brake released, turn the tire on one side, if the differential is set up w/o limited slip the opposite tire will rotate in the opposite direction of the one you are turning by hand. but if the limited slip diff. has extreme wear on the clutch pads it may give you the same result. Or if the tire will not turn freely but rather has the feel of the car being in gear. its most likley going to be limited slip.
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