Volkswagen Passat Forum banner

1 - 8 of 8 Posts

·
Fore!
Joined
·
1,564 Posts
Discussion Starter #1
Can someone explain how the control arm bushings can be damaged during a suspension install if you tighten all the bolts without the weight of the car on the wheels? This is what bentley implies.

And specifically, which control arms would be affected. I am guessing its the bushings where the two upper control arms link into the wheel bearing housing. It seems to me that the pins shouldn't really rotate when you put the wheels back on the ground, but maybe I'm missing something?
 

·
Registered
Joined
·
5,564 Posts
Bentley is referring to the lower control arms. The uppers canot be accessed with ful weight of the car so there is a "preset" distance the upper arms are to be set to in relationship to the lip of the upper mounting plate; IIRC, it's approx. 45mm +/- 2mm.

The lower ones are easy to get to; well, "easier" if you've got access to shop lift. I tried doing this with ramps and it's just not enough clearnance for me and my breaker bar; it's something like 56 ft-lbs. + 90 deg. more; it's that 90 deg. more that kills me. I guess if I had our govenor's strength, I could do it with a shorter one. :)
 

·
Registered
Joined
·
73 Posts
I'm not trying to hijack the thread, but is there a link to the installation instructions for the upper & lower control arms on the site. I searched for "install control arms" and got 1511 posts.

I wouldn't likely take this on myself, but I'd like to show the thread to my mechanic. I believe I saw this once (before I needed new CAs) and there was discussion about pre-loading to prevent damage, etc. These things are pricey and I don't want to buy another set. Thanks!
 

·
Registered
Joined
·
10 Posts
HermanH is right, the last 90 deg is a pain. I wish VW just gave us a torque spec on these. I did mine 3 weeks ago but had access to a lift which made everthing that much easier. We lowered the car down on to 18 inch high blocks and tightened away on the four bolts. VW designed the bushings to be "pinched" and the inner bushing rotates as the arm travels up and down with the rubber than absorbing the rotation. If you do not relax the bushing by loosening and then retorquing with the weight on the wheels, the bushing will prematurely were out.
 

·
Fore!
Joined
·
1,564 Posts
Discussion Starter #5
Thank you for your replies. I was under the impression that when installing new struts and springs (and not control arms) that one or more of the nuts had to be tightened with the wheels on the ground. Your responses are giving me the impression that this isn't the case, and that this applies only to actually installing new lower control arms.

So, am I ok if I installed my springs and struts as per HermanH's instructions, and tightened the bolts connecting the strut to the lower control arm, and the upper control arms to the wheel bearing housing, without lowering the car onto its wheels?

Sorry If I am missing an obvious point.
 

·
Registered
Joined
·
10 Posts
Not quite. If you are lowering the car it will have a new neutral point on the control arms and if you do not relax and retorque the lower control arm bushings, they will be preloaded and prematurely fail. So, if you are lowering your car you will need to relax and then retorque your lower control arms. You will feel them relax when you release the torque. BTW, I also torqued the lower bolt on the strut when the car was sitting on the wheels. So actually 6 bolts on the fronts were torqued when the car was on its wheels. Good luck.
 

·
Registered
Joined
·
56 Posts
OK, it's 6 years later but what the heck. I just installed Koni yellows and H&R sports all around on my B5 30V Variant. I actually used HermanH's instructions! It sounds like I need to relax the 2 lower control arm bolts on each of the front wheels (4 bolts in total for the front) and then re-torque them once they are weighted. How about for the rear? Do I need to loosen and then retorque (when weighted) any of those control arm bolts??
 

·
Registered
Joined
·
606 Posts
With the wheel removed, you can jack on the bottom hub carrier, and establish the full weight on that corner, and verify it is properly pre-loaded by measuring the hub center to the fender lip. Then it is very easy to access all the control arm bushings, upper and lower, and properly tighten them. Simple, simple, simple.
 
1 - 8 of 8 Posts
Top