S4 B8 Control Arms
Author
Discussion

luisjsy

Original Poster:

446 posts

173 months

Monday 16th September 2019
quotequote all
Hi Guys,

Can anyone help me understand something please.

Everyone says that Control arms have to be tighten only when the wheels are under load but i don't quite understand why.
This is the kit https://store.034motorsport.com/density-line-contr...

As you can see every bush has a metal sleeve so when you tighten them it wont affect the bushes and they will be able to rotate with suspension travel.... or am i missing something?

Thanks in advance

shtu

4,577 posts

176 months

Monday 16th September 2019
quotequote all
The metal sleeves are bonded solidly to the rubber parts.

When you tighten the bolts, the inner sleeves are clamped solidly in place to the body - there's no slip or rotation.

Tighten them up with the arms in full droop, then lower the car, you've either

a) applied a 20-30 degree preload "twist" to each bush, which will shorten their life.
b) torn the inner sleeve out of the bush, which has ended their life.


eta - you might want to look at Meyle HD and\or Lemforder components.

Edited by shtu on Monday 16th September 15:30

luisjsy

Original Poster:

446 posts

173 months

Monday 16th September 2019
quotequote all
shtu said:
The metal sleeves are bonded solidly to the rubber parts.

When you tighten the bolts, the inner sleeves are clamped solidly in place to the body - there's no slip or rotation.

Tighten them up with the arms in full droop, then lower the car, you've either

a) applied a 20-30 degree preload "twist" to each bush, which will shorten their life.
b) torn the inner sleeve out of the bush, which has ended their life.


eta - you might want to look at Meyle HD and\or Lemforder components.

Edited by shtu on Monday 16th September 15:30
Thanks shtu,
If the inner sleeves are clamped solidly in place to the body when you tighten the bolts then surely when you jack the car up the wheels wouldn’t drop down as they usually do....

There's has to be some slip or rotation no?

shtu

4,577 posts

176 months

Monday 16th September 2019
quotequote all
luisjsy said:
There's has to be some slip or rotation no?
No. The bush will twist to a certain extent.

What you are avoiding by torqueing at normal ride height is the bush being forced from full droop to full compression.

luisjsy

Original Poster:

446 posts

173 months

Tuesday 17th September 2019
quotequote all
shtu said:
No. The bush will twist to a certain extent.

What you are avoiding by torqueing at normal ride height is the bush being forced from full droop to full compression.
I get it, thanks for that mate smile