1964*Air*Coupe

I don't understand the Rear Axle Codes. On a 1964 Rear carrier you can have a code "CA" which is a non-posi 3.36:1. You could also have a "CB" which is a posi 3.36:1.

Not totally understanding Posi, but this is what I'm thinking:
If you have posi, it seems that both wheels will turn. ie one main drive shaft turn will case the half shafts on each wheel to turn.

On a non-posi, it seems like only one 1 half shaft would have drive. ie one main drive shaft turn will case only one half shafts on each wheel to turn. The other seems like it would be dead and not used.

So that's my thought. Now the question is:
Is what I'm thinking is correct? Why the heck have two half shafts on a non-posi car? Why do you need it?

I know you guys are thinking: This guy is ~ha

alexandervdr

no need for laughs, this video explains the concept of limited slip. . Watching it I learnt something myself (the point about torque pushing the bevel gears out), so thanks for asking your 'stupid' question

Frankie the Fink

I think that video doesn't quite answer the question; both solid axle and independent rear suspension have posi AND non-posi rears. The half shafts provide independent suspension regardless of the posi or non-posi rear end. Meaning one side of the car can 'float' or 'rebound' over bumps/obstacles, etc, without much affect on the other side.

One reason solid axle cars are also sometimes 'live axles' by old-timers ... anything happens to one side its solid nature transfers it to the other.

MikeM

As long as neither drive wheel slips, a non-posi rear will divide the drive torque equally between the rear wheels.

65GGvert

AND, if you only had one half shaft, the other side wheel would fall in toward the center of the car. The half shafts do more than drive the wheels.

GTOguy

How about simplifying things and making it a three wheeler, like a '30's Morgan?

AZDoug

Just a note:

After 50 year, stamped codes don't mean much, too many internal parts can get and have gotten swapped around.

Doug

JohnZ

The "sliding pillar" suspension units on Morgans have a whole new litany of issues to deal with.

stratplus

OK, I have to admit, I had to look up what a sliding pillar is.

GTOguy

And apparently, the Morgan is a Sliding Axle suspension, and not a sliding pillar, per the article! (All I knew was that they were 3 wheelers with that cool *** motorcycle engine up front and that Perter Sellers drove one in "The Party"!)
Thanks to JohnZ for teaching me about a suspension system I had never heard of.....and I'm into really old and arcane stuff, too!

ghostrider20

I think the question is, when you do a burnout with a limited slip does just one wheel lay down rubber, and with the posi unit, both do?

- Mark

still cruzin

Mark,
Limited slip IS positraction! During straight away burnouts both wheels will spin. Think about it...when your car is making a turn the wheels will be rotating at different speeds. (inside outside) The limited slip clutches allows one wheel to take over at this point.

Non-posi (non-liminated slip) you only have one drive wheel! So only one wheel will put the rubber down. The other wheel is just there for the ride.

Bob

Donny Brass

better explaination

MikeM