jack stand placement
#1
12-10-2016, 01:31 PM
#3
12-10-2016, 03:50 PM
Veteran Member
A point to note is that some people have had "leveling" problems after jacking the car up.
Quote from Don B :
"Your car had almost certainly entered "Jacking Mode" in which the air suspension is disabled to avoid unnecessary and potentially counterproductive adjustments while the car is on jacks or a lift. When the system senses one corner rising (on the jack), it first responds by lowering the suspension, but when it does not sense a corresponding reduction in height, it goes into Jacking Mode.
The document at the link below is the best explanation of the suspension behavior I have found, and it explains that to get the car out of Jacking Mode and restore air suspension operation you may need to drive the car above 2 mph:
http://www.mediafire.com/view/7rdkgg...on_Section.pdf
It may be possible to spin a wheel that fast while the car is still on the jack, but the manual doesn't make it clear whether the Air Suspension Control Module (ASM) sees the signals of all the wheel speed sensors or relies on only one sensor for road speed signals.
I don't know what jacking point you used, but the Workshop Manual and Dealer Training New Model Introduction manual specify the jacking points to be used and insist that two jacks must be used on an X350 to raise two wheels at a time so the aluminum monocoque is not harmed by being twisted too much. When I have to use one jack, I am careful to not raise the car any higher than necessary to reduce the amount of twist on the monocoque.
You can download the Workshop Manual in six sections from the 'HOW TO' quick links thread near the top of the home page of this X350 forum".
Quote from Don B :
"Your car had almost certainly entered "Jacking Mode" in which the air suspension is disabled to avoid unnecessary and potentially counterproductive adjustments while the car is on jacks or a lift. When the system senses one corner rising (on the jack), it first responds by lowering the suspension, but when it does not sense a corresponding reduction in height, it goes into Jacking Mode.
The document at the link below is the best explanation of the suspension behavior I have found, and it explains that to get the car out of Jacking Mode and restore air suspension operation you may need to drive the car above 2 mph:
http://www.mediafire.com/view/7rdkgg...on_Section.pdf
It may be possible to spin a wheel that fast while the car is still on the jack, but the manual doesn't make it clear whether the Air Suspension Control Module (ASM) sees the signals of all the wheel speed sensors or relies on only one sensor for road speed signals.
I don't know what jacking point you used, but the Workshop Manual and Dealer Training New Model Introduction manual specify the jacking points to be used and insist that two jacks must be used on an X350 to raise two wheels at a time so the aluminum monocoque is not harmed by being twisted too much. When I have to use one jack, I am careful to not raise the car any higher than necessary to reduce the amount of twist on the monocoque.
You can download the Workshop Manual in six sections from the 'HOW TO' quick links thread near the top of the home page of this X350 forum".
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Don B (12-11-2016)
#5
12-12-2016, 12:39 PM