Need guidence on rotating driveshaft/wheels while car is on lift

[UnhandledException]

I am trying to diagnose a strange noise coming from the driveterrain in slow speeds which feels like something is rubbing somewhere. As a test I want to put the car on jack stands and put it in neutral and rotate the tires and driveshaft to see if it freely rotates and if any rubbing or strange noise is present.

I have some questions:

- Once I lift the car and its on jack stands, I release the hand brake and put the car on neutral.
- At this point the driveshaft is disengaged from the transmission.
- Do I need to go under the car and rotate the driveshaft OR can I simply rotate one of the wheels and both the other wheel and the driveshaft will also turn?
- Instead of doing this by hand, can I run the car on 1st gear and very gently release the clutch to simulate the driving motion? Is this harmful to the car?

Any other tips are welcome

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[TaraFirma]

You can rotate the DS and turn both wheels.
Depending on how much you trust your jack stand setup, you can run the car in gear. I would be VERY CAREFUL when doing this though.

 

[UnhandledException]

You can rotate the DS and turn both wheels.
Depending on how much you trust your jack stand setup, you can run the car in gear. I would be VERY CAREFUL when doing this though.

Will both the driveshaft and other wheel will rotate if one wheel is turned?

 

[JAJ]

Will both the driveshaft and other wheel will rotate if one wheel is turned?

That depends on how much resistance there is in the driveline - if you're turning one wheel, something else has to turn as well. If the driveshaft/gearbox output shaft has the most drag, then the other rear wheel will turn backwards as you turn the one near you forwards. If the other rear wheel has the most drag, then the drive shaft will turn. It's possible that if the two drag pathways have about the same resistance to turning. In that case, both will turn.

If I was to speculate, I'd guess that the driveshaft will turn before the other wheel because of drag from the brake pads on the rotor. That said, you can stick a screwdriver into one of the vent holes on the brake rotor to block the opposite wheel from turning and that will force the driveshaft to turn. If you put the transmission in gear, you can force the other wheel to turn.

 

[fpa1974]

If it is in neutral and up in the air, if you rotate one of the rear wheels the other rear wheel will spin in the opposite direction (limited slip diffs do this vs open where both wheels spin in the same direction) and the driveshaft will spin.

 

[TDC]

I had a flap/thrum sound from the driveshaft tunnel. Turned out to be the driveshaft label coming loose.

 

[GreenS550]

The old rule with positraction which your Mustang has is that if you rotate a wheel, it will rotate the opposite wheel the same way and turn the driveshaft as well. So, yes, you should be able to rotate the driveshaft by turning the wheel.
However, with that said, I personally would get under the car and rotate the DS by hand to visually examine the DS and center mount, Joints, etc. There will be a front and rear Ujoint for each half of the driveshaft with a center bushing. On the S197s sometimes the center carrier would get sloppy and cause issues.
Under NO circumstances would I try to figure it out with the car running in gear on jackstands.

 

[Zombo]

Will both the driveshaft and other wheel will rotate if one wheel is turned?

Yes, both wheels will get locked together and the driveshaft will turn. The 350 employs a self locking Torsen differential.

A household example of the locking principle of a worm gear design would be an adjustable wrench.

[ame]

 

[UnhandledException]

Interestingly when one wheel turns only the driveshaft turns the other wheel doesnt. If I turn the driveshaft, both wheels turn.

Anyways, I couldnt figure out where this noise is coming from. Every single one of my brake pads make a hissing sound from the rubbing to the brake disc. 2 of them make this noise unevenly while the other always make. I dont know if thats the noise or something else.

Best way to describe the noise is when the car slows down to say 10-20mph, you feel this strange rubbing noise thats clearly coming from a rotating surface. I can feel it on the brake pedal as well. I think I always had this since day 1 or early ownership but since I put aftermarket wheels on (signsture wheels), it seems to be more noticeable.

 

[fpa1974]

Interestingly when one wheel turns only the driveshaft turns the other wheel doesnt. If I turn the driveshaft, both wheels turn.

Is the car in gear?

 

[UnhandledException]

Is the car in gear?

No its on neutral and hand brake disengaged

 

[fpa1974]

No its on neutral and hand brake disengaged

I think if you put it in first it will spin both rear tires. I know I wanted to test for a rubbing noise myself and went through the exercise.

 

[scannon]

Best way to describe the noise is when the car slows down to say 10-20mph, you feel this strange rubbing noise thats clearly coming from a rotating surface. I can feel it on the brake pedal as well.

That is a typical symptom of warped brake rotor(s).

 

[Demonic]

That is a typical symptom of warped brake rotor(s).

It's my understanding that warped rotors are exceedingly rare, and more often attributed to pad deposits.
http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

But either way, it sounds as if he's saying he feels the rubbing through the brake pedal, but that it's still also present even when not braking, in which case I don't see how it would be associated with pads or rotors. Unless the hand brake is somehow partially engaged?

 

[fpa1974]

And sometimes the vibrations/rubbing feel will travel through the chasis and be felt in the brake pedal even if it has nothing to do with the brake. It is difficult to assume either way without proper diagnosis (but a good starting point in the elimination game I guess).

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