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Discussion Starter #1
Hello,

I noticed somebody mentioned suspension air bags in the towing thread. I understand that you can't put a lot of weight in the back of the car (in particular, when not using weight distribution). However, since I am towing fairly heavy trailer (with weight distribution) air bags would be helpful to give some rest to the suspension.

Does anyone know about aftermarket air bags solution for X5?

Thanks!
 

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Nuclear engineer
02/2012 X5 35d M57Y CPO 98K miles NOKIAN WR G3 12K miles
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Utter bafflegab! Moment (length times force) is conserved and the sum must be zero where there is no motion.
 

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Discussion Starter #3
Thanks. Anybody else with more practical suggestions? :)
 

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Limited options as all the air ride kits come with front and back. I think the cheapest solution would be to purchase arnott bags and just put together an air management system yourself.

I've been down this road and as much as I love the idea of going with an aftermarket air ride setup, the cost just doesn't seem practical.
 

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Resident Curmudgeon
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,

air bags would be helpful to give some rest to the suspension.
Can't help with a vendor...but the airbag systems usually sit on top of the springs- so it doesn't give the suspension annoy 'rest'.

Let's say your trailer plus crap in the back is 700 lbs, and the rear is rather low.

With airbags, it is still 700 lbs and the springs are still compressed- however you can infant the bags to level the rear.
 

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Discussion Starter #6
OK, then I do not see that much benefit in my case. I do not have that much squat. Just thought that the air bags will be taking some load instead of the springs and shocks.

Thanks!
 

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Discussion Starter #7

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I called the manufacturer and they told me that if I provide the diameter of the springs plus the height, they should be able to recommend proper airbags.

How to measure the diameter and the height of the springs when the car is on the ground (not on the lift)? I looked below the car and you can hardly see the rear springs, so I have no idea how to get the measurements...
 

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Nuclear engineer
02/2012 X5 35d M57Y CPO 98K miles NOKIAN WR G3 12K miles
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From the part number? Get the PN from RealOEM, then use the PN to search aftermarket vendors for replacements that usually have further specifications.
 

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Discussion Starter #10
Thanks. Maybe diameter I can get from the specs, but would rather not get the height under load. Therefore, I need to crawl somehow under the car to get this measurement.
 

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Nuclear engineer
02/2012 X5 35d M57Y CPO 98K miles NOKIAN WR G3 12K miles
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Loaded length is NOT intrinsic to the spring as it requires the extrinsic load that is not standard or known accurately.
 

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Discussion Starter #12

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Nuclear engineer
02/2012 X5 35d M57Y CPO 98K miles NOKIAN WR G3 12K miles
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I found this.
Important!
Both coil springs on the relevant axle must be replaced only in the event of corrosion breakage!
For all E70/E71/E72 vehicles: When replacing coil spring, always renew spring pad at bottom

Note:
The coil spring is allocated in the Electronic Parts Catalogue (EPC) under the "Spring table" menu item after the vehicle identification number has been entered and the optional equipment of the particular vehicle has been selected.
[my emphasis]
 

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Discussion Starter #14
I checked the airbag route - it appears to be doable, however, the surface at the top and bottom of the spring (inside the spring, where the airbag would be installed) is not flat.

To fix this I thought that maybe the yellow parts from the kit could be used

https://thmotorsports.com/i-2429200.aspx?2429200-BMW-X5&gclid=Cj0KCQiAi7XQBRDnARIsANeLIesH3VPzNNEv1YLmlnWvO7xXSjj1SQ9OJcVNFSJecbjDawJpqzFRBs0aAgbHEALw_wcB

For now, I decided to add those inserts. I will be installing them over the weekend and towing on Wednesday. I will report back how they work.

https://www.amazon.com/gp/product/B009JC42PE/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1


I called the manufacturer and they told me that if I provide the diameter of the springs plus the height, they should be able to recommend proper airbags.

How to measure the diameter and the height of the springs when the car is on the ground (not on the lift)? I looked below the car and you can hardly see the rear springs, so I have no idea how to get the measurements...
 

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Discussion Starter #15
Update after 400 miles towing. Inserts are working very well, keeping the car level with 3 adults / 2 kids / a dog / the trailer attached. I have not noticed difference in driving quality when driving without the trailer - the car is a bit stiffer, which I like.



 

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Reviving an older thread- Kanar, I have aftermarket bags in the base coil rear in my X5. I do a lot of 5 to 7k lbs of towing, long distance with my X5D. I tow my drift car around a bunch. Aftermarket bags are WONDERFUL and make the towing experience so much more enjoyable.
 

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I have a 2011 BMW X5 diesel and a 1973 25 foot airstream trade wind with a curt 17499 hitch. https://www.etrailer.com/Weight-Distribution-Hitch/Curt/C17499.html?gclid=EAIaIQobChMIzLHs8ube6QIVHh-tBh0HwAoGEAAYASAAEgIjtfD_BwE The tongue weight is 600 lbs and the dry weight is 4100 lbs. With the Curt system, do I need suspension airbags? It looks like some of the suspension airbags mentioned are not available. I am looking for suggestions on what suspension airbags are best and if they should be professionally installed? Thank you for any insight.
 

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Having aftermarket airbags allows you to balance/trade off how much or little weight transfer you use from the hitch and still maintain the correct front/rear ride height.

I prefer to use some but not a lot of WD and anti-sway, because it improves the overall towing performance without overly stressing the hitch and hitch attachment to the body.
 

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Discussion Starter #19
As far as I understand this, air bags do not transfer weight from the rear axle to front. Only weight distribution hitch can do this. Air bags can actually mask the problem with heavy tongue weight and light front axle.
 
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