|
|
SUPPORT ZPOST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS! |
Post Reply |
|
Thread Tools | Search this Thread |
11-14-2016, 01:50 PM | #1 |
Private First Class
26
Rep 195
Posts |
Rear wheels spinning in neutral?
I had my baby up on jackstands with the wheels off. With the engine idling in neutral the rear hubs were spinning slowly. Easy to stop just by holding the hub by hand, but I've never noticed this before. Of course, I rarely run the engine while the car is in the air. Is this normal? An indication of clutch wear? Should I be worried?
|
11-14-2016, 05:06 PM | #2 |
Colonel
877
Rep 2,543
Posts
Drives: Z4MC-X3-35i-525i, Corrado G60
Join Date: Nov 2007
Location: MD
|
Since all the gears in the trans are spinning, yes the the wheels can turn from oil drag on the output shaft of the trans. I've seen it with other cars, though I never tried it on my Z4.
|
Appreciate
0
|
11-14-2016, 05:12 PM | #3 |
Midlife Crises Racing Silent but Deadly Class
1820
Rep 5,337
Posts
Drives: 2006 MZ4C, 2021 Tesla Model 3
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day
|
Normal. All manuals will do this.
If my understanding of manual transmissions is correct, while in neutral the driveshaft is disconnected to the input shaft, but the entire clutch/pressure plate assembly is spinning freely while immersed in transmission fluid. That motion influences the output shaft and cause it to spin despite the two shafts not physically being connected. While on the ground that motion is easily overcome by the friction of the tires vs. surface. When up in the air, enough energy gets transferred over to cause free hanging wheels to spin. EDIT: What Pungo said.
__________________
Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
|
Appreciate
0
|
11-16-2016, 12:28 PM | #5 |
Private First Class
86
Rep 166
Posts |
|
Appreciate
0
|
11-20-2016, 11:14 AM | #6 |
Captain
433
Rep 753
Posts |
Agreed on theory, but our clutches are dry and sit outside the "transmission" so to speak. And, I have observed the same on my car when on stands.
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|