noob question: effect of differential on wheels

[yomar]

Guys, a newbie needs enlightenment.

Yesterday, I raised the rear of my vehicle (two wheels on jackstands off the ground, front wheels on the ground). When I turned one rear wheel, the other moved the opposite direction. I read somewhere that this was normal because of the viscous coupling in the differential.

Today, I did the same procedure on my dad's 1969 mustang. I noticed that turning the right rear wheel also turned the drive shaft, but the left rear wheel did not move at all. When I rotated the left rear wheel, neither the right rear wheel nor the drive shaft moved.

Is this normal? if it is, can someone explain to me why? If this is not normal, where could the issue be?

additional info: both cars are rear wheel drive.

Thanks in advance!

 

[stangman16]

Sounds like an open rear end, no posi-traction or tracion lock if only 1 wheel is turning.

 

[tx65coupe]

I know that if you rotate one wheel and the other wheel rotates the opposite direction, that means that car has an open differential or one wheel wonder. If the other wheel rotates the same direction then it has some form of posi, which means that both tires spin when you step on the gas. I don't know what it means when the other wheel doesn't move. Was the car in neutral?

 

[Tanus]

open dif, fine for regular cars, actually good for people who have a good amount of HP but no driving skills- easy to go sideways and lose control on a posi car, open dif will spin without going sideways.

 

[yomar]

Thank you for the responses. Really appreciate it.

Yup, the gear was in neutral when I performed the tests. Do you guys think I need to have the diff repaired? I haven't found any resource on the net about this problem. Differentials can be really confusing

 

[woodsnake]

Your diff is working perfectly, you don't have problem...

YouTube - How does the differential work? Aroundth1937

 

[D.Hearne]

Your diff is working perfectly, you don't have problem...

X2 nothing wrong with it. Your Dad's car has a sticking or dragging brake though. if the opposite wheel's not turning.

 

[yomar]

Thanks so much for your inputs! I'll definitely check my brakes. I'm just waiting for the brake kits to arrive.

Happy holidays everyone!

 

[ron67fb]

OK I only visit here once every few months so pardon me for being late to the game, but:

When I rotated the left rear wheel, neither the right rear wheel nor the drive shaft moved.

How does that happen on something that is working "correctly"?

 

[Wart]

OK I only visit here once every few months so pardon me for being late to the game, but:

When I rotated the left rear wheel, neither the right rear wheel nor the drive shaft moved.

How does that happen on something that is working "correctly"?

(I wondered if someone was going to pick up on that.)

It doesn't.

I'm guessing Pops car has a buggered up locker.

 

[2+2GT]

Today, I did the same procedure on my dad's 1969 mustang. I noticed that turning the right rear wheel also turned the drive shaft, but the left rear wheel did not move at all. When I rotated the left rear wheel, neither the right rear wheel nor the drive shaft moved.

If you turn the LH wheel, and neither the driveshaft or RH wheel turn, it is extremely serious, either the differential or axle are broken and the car should be flatbed towed to a repair facility at once, as it would be hazardous to drive the car even in the driveway.

Either that or you need to look again.