Drive Shaft Turning In Neutral -One Wheel Off the Ground - YotaTech Forums



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Drive Shaft Turning In Neutral -One Wheel Off the Ground

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Old 08-10-2017, 10:53 AM   #1
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Drive Shaft Turning In Neutral -One Wheel Off the Ground

Hi guys,
While I was working on my brakes, truck was idling in neutral with one wheel off the ground and noticed the drive shaft turning with the hub. Stops when hub is stopped. Is this normal? Does the clutch have some engagement with flywheel even in neutral, or should I adjust something?
TIA
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Old 08-10-2017, 11:30 AM   #2
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"neutral" meaning... foot on the clutch? trans not in gear?

There are lots of little things rotating, and the light friction between them all causes things to spin. My truck did this (before I started my swap), I think you're fine.
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Old 08-10-2017, 12:11 PM   #3
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Originally Posted by irab88 View Post
"neutral" meaning... foot on the clutch? trans not in gear?
There are lots of little things rotating, and the light friction between them all causes things to spin. My truck did this (before I started my swap), I think you're fine.
Manual transmission in neutral. Yeah, I though the clutch and flywheel are so close to each other (like brake pads and rotor / shoe/drum) that there would slight rubbing.
Thanks, Irab!
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Old 08-10-2017, 12:43 PM   #4
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If one rear wheel is ON The ground and the other rear wheel is OFF the ground, the differential will "connect" the drive shaft to the wheel that is in the air

This is why you get stuck when you DONT have a "locker" or other traction adding differential

In theory, there should be VERY LITTLE frictional drag on the wheel that is in the air, any slight imbalance (pebble caught in the treads) should cause the wheel to rotate - which through the differential, will cause the drive shaft to spin via the pinon gears rotating in the diff

NOW - if you have a Locker or traction diff - things get different
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Old 08-10-2017, 12:53 PM   #5
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Originally Posted by ewong View Post
If one rear wheel is ON The ground and the other rear wheel is OFF the ground, the differential will "connect" the drive shaft to the wheel that is in the air.
Tnx, Ed.
I understand about the unlocked diff.
This is actually while manual transmission is in neutral.
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Old 08-10-2017, 02:15 PM   #6
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Originally Posted by RAD4Runner View Post
Manual transmission in neutral. Yeah, I though the clutch and flywheel are so close to each other (like brake pads and rotor / shoe/drum) that there would slight rubbing.
Thanks, Irab!
Wait, are you pushing in the clutch when you are seeing this?

If you are NOT pushing in the clutch and the transmission is in neutral, the input shaft of the transmission is still spinning at the same speed as the crankshaft of the engine, just like normal driving (without letting the clutch slip). When you are not pushing in the clutch, the clutch is fully engaged no matter if you are in neutral or in gear. I bet the little bit of friction from the fluid and parts inside the transmission is causing your wheel to turn.

How difficult is it to stop the wheel from rotation? I don't think it would take much because you just need to overcome the friction and movement of the fluid against the gears. (If I am thinking about this correctly ) If the transmission is in neutral, the gears are not physically connected from input to output shaft.

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Old 08-10-2017, 02:57 PM   #7
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Red face

Just why pray tell did you have the engine running while it was on Jack Stands ??

Inquiring minds would like to know??
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Old 08-10-2017, 03:26 PM   #8
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Originally Posted by old87yota View Post
...
...the input shaft of the transmission is still spinning ... ...friction from the fluid and parts inside the transmission is causing your wheel to turn.
AHA! There you go. Like the liquid coupling / fan clutch! I forgot about the clutch being engaged and input shaft turning.
Thanks, guys! [/QUOTE]

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Just why pray tell did you have the engine running while it was on Jack Stands ??
LOL! Don't worry, Craig; I have a Final Destination mind and had seen enough bloody safety training visual aids in the Navy, so I do it safely. I just needed to check something but now I forgot which one it was.

Last edited by RAD4Runner; 08-11-2017 at 08:08 AM.
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Old 08-12-2017, 02:41 AM   #9
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Red face

When it is a little Cool in the Morning around 0 F

The gear oil is thick enough with out the parking brake engaged the truck will move in neutral even more so if the transfer case is in low range
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