ring gear

[pjbizjak]

Hello all, I have a 04a built 68 z/28 amaro and recently I pulled off the rear differential cover and want to know what the numbers on the ring gear mean...11 41 12 67, beside a date code do they have any other meaning, gear ratio?

[bertfam]

Yes, 11 41 means 3.73 ratio and 12 67 means December, 1967.

Ed

[KurtS]

11 41 is the tooth count. 41 / 11 = 3.73

[pjbizjak]

Then why did I have to turn the pinion 4 plus rottions yo get the wheel to mke 1 rotation? 4/11?

[Tx-Z 302]

Unless you have the tire marked and are very very careful the turning the pinion and you ring the tire spinsis very tricky between 3.73 and 4.11.

[olddragracer]

The procedure for checking the rear end ratio without removing the cover. Jack the rear of the car off the ground. With both wheels off the ground, transmission in neutral, hold one wheel from turning, mark the position of the  pinion and the other rear wheel, then turn the marked wheel two full turns. Count the turns on the pinion. Three and three quarter turns on the pinion would be 3.73. This procedure will take two people. If the car has a limited slip differential [positraction] you can try jacking only one wheel letting one being held by the ground. With positraction it will take an extra effort to turn the one wheel, should be 70 ft. lbs. or less with an original diff. case. To check the ratio with the cover off divide the number off teeth on the crown gear by the number of teeth on the pinion gear. 41 on the crown gear divided by 11 on the pinion = 3.73