Sway Bar End Links

[Guy_H]

The failure is all about the length of the sway bar link, the angle of the head (the way it pushes up with a twisting force twists / sideloads the coilover bracket).

You need to have the correct link for the application, and generally the stock one wont work & cause a failure (because of the above) unless the coil over was designed to use stock mounts.

To work out the length you need (if you are making your own), you need to have the car sitting level (loaded), the sway bar set to its intermediate movement position, and then set the sway bar link length from that. Once the length is set, then position the ball head in the centre of the steering movement plane, so there is no side load from turning. This is the part that starts to flex the mount on the strut & causes the failure.

Here is a pic of the links supplied with the VWR coilovers, being installed on a customers Golf R. You can see the adjustable heads / ends.



Nolathane make a good adjustable product, you need to measure the bolt hole size for your application - but they are a great cost effective solution:

Nolathane 42790 Front Sway bar - link assembly

[dylan8]

Instead of going to the expense of adjustable drop links you can actually have the standard ones shortened to suit your setup.
You wont get as many "Scene points" but it will be just as functional if not better. (you still need to ascertain if there is any length issue here. The standards ones may be just fine.)

I disagree, more scene points for custom stuff!
We made some custom ones for my mk4 (bit longer then stock in my case) after my whiteline ones failed within the week.

second Tim, can you confirm you need shorter or longer? is the sway bar hitting on something?
Answered by Guy

[Guy_H]

P.S. in some of the previous failure pics in the thread, you can see it was a sideways force that has twisted the mount to start with.

[Idle]

Quite agree with Tim.

Pic's show signs of metal fatigue — always a sign of lack of rigidity (but then, if you make them too rigid you shift the motion somewhere else...)

[Tim]

Im no engineer but if you have a look at a bilstein strut for instance you can see the force is then distributed to the shock body which is cylindrical stainless steel. Not only that. It then has multiple weld points which help resist shear forces which what cracks welds.

[noone]

I'm not clear on how long an ideal bar length / angle should be. I feel the link should be as vertical as is reasonable whilst ensuring the force into the bar makes the bar twist (the bar ends vaguely horizontally in line with the mounting (bushing) locations. Does that make sense?

[Guy_H]

I'm not clear on how long an ideal bar length / angle should be. I feel the link should be as vertical as is reasonable whilst ensuring the force into the bar makes the bar twist (the bar ends vaguely horizontally in line with the mounting (bushing) locations. Does that make sense?

That's exactly why you need to measure it - loaded, unloaded, and allow for full travel, full droop & full steering angle.

[thezoneR32]

.........You need to have the correct link for the application, and generally the stock one wont work & cause a failure (because of the above) unless the coil over was designed to use stock mounts.

Thanks for all your contributions fellas good stuff. But getting back to my issue...paraphrasing Guy above "unless the coil over was designed to use stock mounts". In my case they are saying that the struts were designed to be used with the oem mounts (end links) but also the oem sways which I wasn't using.

I've done a bit of physics research and it seems the transfer of forces in a corner goes from heavily loaded axle to the end link via the strut, through the anti-sway bar, then to the end link on the other side through the strut and back into the axle. So does the adjustable end link need to flex and reduce the torsion from one strut on one side and back into the strut on the other? I would think not as any flex in the end links would diminsh the rigidity of the sway bar negating their existence?

I'm just trying to work out if there's really any point to these adjustable end links, whats wrong with the oem ones? It seems to me that this KW strut juts didn't do its job.