Lotus99

I'll admit I've not read the manual yet...

My friend's Allroad you have to lock the air suspension before you jack up the car, otherwise you can mess it up badly from what I've heard, so considering our cars have the adjustable air suspension in the rear, I thought to ask if I need to do anything before jacking up the car to swap over my winter tires?

Also, on my 335, the body is stiff enough that if I raise the car using the rear jack point high enough, both the rear and front wheels lift off the ground, so saving me having to jack up the front separately later.

I'll need to do it a lot higher given the extra ground clearance on this car, but if possible, would it be bad for the suspension to jack up the car using the rear jack point high enough to lift the front wheel too?

How about for the tires? Is that putting too much pressure on the opposite side tires' sidewalls for the 15 minutes or so I'm swapping the other side?

Anzafin

I don't have the touring version of our car, but this is what I think:

1) I don't believe you're able to do this. Just lift one end at time.

2) Read above. Besides, the car's own jack is crap, use a proper floor jack.

3) No.

- Antti -

crewzer

1) Make sure the jack pads are in place. If it appears that yours are prone to falling out, then you may want to order an extra one or two to keep with the car jack.
2) Consider using a jack pad adapter and a floor jack.

HTH,
Jim / crewzer

Lotus99

Thanks guys. So it sounds like for the suspension at least, there's nothing I need to worry about before jacking up the car.

I do have a proper floor jack, and an adapter, as my other car's a 335, and I'd bought the stuff for swapping my winters, so I'm set that way. After swapping a set of winters on two cars myself for just one year, the investments paid for themselves, compared to going to a tire shop.

Kell

It shouldn't take 15 mins with the car in the air.

I've not changed a wheel myself for years, but I was always told that yoiu keep the car jacked up for the minimum amount of time. Loosen all the bolts with the car on the floor so they're nearly off.

Jack it up.

Get the wheel on as quickly as possible and do all the bolts up so they're tight but not necessarily at the correct torque.

Lower car. Finesse the bolts while it's solidly on the ground.

mmitev

Please allow me to make one "correction" here, although it's just my personal opinion:
1. Raise the car so that the wheel still touches (albeit firmly enough) the ground.
2. Only now loosen the bolts a bit, only to the extent that they can rotate freely.
3. Jack up another inch so that the wheel is in the air, and only then loosen the bolts completely and remove wheel.

The mounting of the wheel should happen in the reverse logic - i.e. tighten the bolts as much as possible in the air. When wheel touches firmly the ground, tighten bolts to correct torque. Only then lower the car solidly on the ground. Now you can check the torque again, but it should not be really necessary (ideally you should check the torque again after a day or two).

tom_il

Very good question. when changing to my winter tyers i could hear the compressor switching on.
I am not sure if the height control is also working, also when the ignition completly off. If it is the height control wants to compensate when jacking up the car. I had the tailgate open when jacking up, not sure if this had influence on the height control beeing active or not.

Lotus99

What's the logic behind why you can't loosen the bolts using a breaker bar with the car fully on the ground, then lift car?

I remember all the hissing and stuff as well from the last time I rotated my tires (car might have still been off too), which is why I was wondering.

A90

Don't forget to open the car. The alarm will go off otherwise (happened in my case)

yeewiz

There's 3 arguable points to this jacking up the car thread. I agree with mmitev on all 3:

1) Do you break the wheel nuts free with or without jacking up the car. If you partially jack up the car leaving the wheel firmly on the ground, you've lightened the 1000 lb load (4000 lbs car / 4 wheels) on the nut and wheel making it easier for you to break the nut free.

2) How much do you loosen the nuts after you beak them free: IMO, all you have to do is break the nut loose. Once you have the wheel in the air, it will spin off without any more effort. To "loosen all the bolts ... so they're nearly off" means you have to figure out when they nearly off and is just unnecessary extra work.

3) (This is probably the most important of the 3 questions) When do you torgue the wheel nuts: Torgue the nuts after you've lowered the wheel so it's firmly on the ground but not completely on the ground. Torguing with the wheel partially on the ground means you get a more accurate torgue reading because you're not trying to tighten the nut with 1000 lbs of pressure between the nut and wheel.