A&Q about 350Z
Q:
hi guys i am new to this site so thanks for your help. i purchased a 61 vette and am trying to find out the rear end gear ratio. it came with 6 different sets of gears from the factory. { 3.08-3.36-3.55-3.70-4.11-and 4.56}. there should be a tag on the rearend that tells the gears inside {you go by the shape of the tag} but its missing. the only thing i can do is count the tire rotation and drive shaft. the tire goes around once and the drive shaft turns 1 3/4 times. can anyone help me to figure this out. thanks for your help in advance
A:
I've never had much luck with that method for the exact reason you just experienced. I don't know why, but it never worked for me; limited slip or not.
The best way is to pull the cover off. Turn the ring gear until you see some stampings. That is the ratio of ring gear teeth to pinion teeth. If its 41/10 (sometimes listed as 10/41) its a 4.10 ratio. 41/11 is 3.73 and so on.
A:
Limited slip, live axle rearends are super simple. If both tires are jacked up in the air, and if the limited slip clutches are even partially functioning, and the brakes aren't rubbing, you'll get a result like; 1 tire revolution and three revs of the pinion.
It HAS to work this way.
If it does not, there is a problem in the limited slip unit, or you do not have limited slip ("Positraction").
If the limited slip clutches are toast, the opposite tire may be revolving in the opposite direction than the tire that you are turning (again, providing the car has both rear wheels in the air) . This'll give you a low revolution count at the pinion, or none at all.
Disclaimer--
If you have some sort of horrible, abortion style of diff., like a Detroit Locker or some such, well... I have no experience there.
A:
I agree.
I expect only one rear tire was rotating when katlou was counting.
If this is the case, the rear end ratio is 3:55 to 1 and the posi is either really worn/broken or does not exist at all.