E46 Fanatics Forum banner

Powerflex centered FCAB problems

19K views 51 replies 10 participants last post by  tomoyer 
#1 ·
Got all my new suspension stuff installed, but have a problem with the FCAB. It seems to that as i drive at least one side will wiggle up the control arm and unseat from the FCAB lollipop. This makes the car shimmy under braking and squeak when i hit any bumps.

I saw the washer in the package, but to be effective it would have to be gigantic. The black insert piece sits way too far back on the arm for the little washer to work.

Any ideas here, or have i just hosed up the install somehow?
 
#4 ·
Ok, looks like they are staying put now, all the way in the carrier. I now have a "clunk" on the RH side...:banghead: Every single part up there is new and tight. Anything else i should check? Here's what i've replaced in the past 3 weeks.

Shocks, shock mounts, control arms, inner ball joints, powerflex fcabs.

The tie rods are ~8 months old.

I cannot get any movement out of the wheel/hub in the air, but you hit the slightest bump, and clunk clunk clunk.
 
#6 ·
Yep swaybar link was the problem.

But... no matter what i do, as soon as i brake hard, the RH FCAB slips up the arm.. I've had it off now 4x. If i drive like a grandma all is well, but if i have to brake at 50+ there is an audible "pong" noise and the black piece slides up the arm (i put a mark, it is being covered). I cleared the arm of anything (grease whatnot) and put it back on, but after ~20 miles, same problem.
 
#9 ·
ok, i have those centered pf bushings as well and installed them with ease.

You just need to be careful and precise at the point where the carrier bolts rest, and dont slide the bushing too far.
I didn't use soap and water on the control arm like most people do. however i did use the washer with a clamp behind it for a peace of mind in case the black piece slides out.
Six months so far and mine haven't moved a mm. They are solid.
 
#13 ·
Ok guys... Sanded the bejeezus out of the arm ends, way more than before. So far so good. Hard braking tests done and no movement on the bushings, they're still in the bore. Thanks for all the info.

Jason-- Thanks for those pics. I'll keep that in mind if the center piece slips again.
 
#15 ·
I've had no problems with my PowerFlex Bushings since putting in. To install on the Lower Control Arm, I used a lil bit of dishwashing detergent and water to act as the lube. When the water/detergent dries, its solid, and will not "run" up Control Arm Shaft. I have about 25,000 mile on mine so far.
 
#19 ·
Carter22, was the inner hole in the AKG Bushing Set OFFSET? Can not tell in your photos. At least with the PowerFlex Bushings, the correct ones for an XI have the center hole slightly off center, whereas for the 2 WD Models (not sure about the Ms), the inner hole is centered. That is about $14.00 cheaper than the PowerFlex. Were the AKGs 2 piece?
 
#20 ·
They are one piece with a centered hole. Kubica had referenced that he had an alignment with caster sweep pre and post changing to centered hole e36 bushings, with the specs being identical. Stock bushings are very slightly offset. Return to center, high speed stability, nothing at all has been negatively affected so far as I can tell.
 
#21 ·
The "centered" or "off-set" hole in the bushing has little to nothing to do with Caster and has everything to do with Camber. The only real way to change the built in Caster is to use a set of adjustable camber plates at the top of the struts, not only will they allow for about +1 degree to -3 degrees of camber adjustment, they will also allow for caster adjustment. So, the caster would not be affected using the centered hole E36 Bushings, the camber would be affected.

Caster: the angle at which the steering axis deviates from vertical, the steering axis is an imaginary line about which the front wheels turn. most cars are designed with a steering axis which is inclined toward the rear at the top (positive caster +), giving them directional stability and self-centering steering. NON ADJUSTABLE

Camber: is the angle at which the wheels tilt away from vertical as viewed from the front or rear of the car. wheels that tilt in at the top display negative (-) camber, whereas wheels that tilt out at the top display positive camber (+). camber influences corning and directional stability. a difference in camber between 2 front OR 2 rear wheels may cause the car to pull to on side, misadjusted camber will cause uneven tire wear. Slight adjustment can be made without optional parts.

Toe: is the measurement of the amount that 2 wheels on the same axle piont towards each other (toe-in) or away from each other (toe-out) in their direction of travel. Toe is fully adjustable. toe affects directional stability and tire wear, and also has some effect on how the car responds to steering input. too much toe will cause tires to "scrub" and wear unevenly and more quickly, whereas, too little toe (to near zero) may cause the car to be less stable and wander slightly at highway speeds.
 
#22 ·
The "centered" or "off-set" hole in the bushing has little to nothing to do with Caster and has everything to do with Camber.
I disagree. Moving the control arm inwards or outwards at the rear mount affects the fore and aft movement of the wheel in the wheel well. The arm pivots around the subframe mounted balljoint.




Either way and change is negligible and works great.
 
#23 ·
Not at all, it affects how much pressure is put on the control arm, moving it away from or towards the center of the car, thus changing the CAMBER ANGLE, not eh Caster. The control arm pivots between the inner and outer ball joint, not just the inner.
Now if you could put longer or shorter control arms in the car, you would be changing the Caster Angle as you would be either pushing or pulling the bottom of the strut towards or away from the vertical line as in your diagrams of CASTER. This is what Adjustable Camber Plates allow you to do, slightly change the top of the strut away from or towards the vertical, as well as letting you adjust the CAMBER.
Even removing the "pin" will not allow you to change Caster, but will let you slightly adjust the Camber.
You may disagree with me and the definitions of Camber, Caster and Toe, but then you are disagreeing with automotive engineering and physics. Glad it "works great", but you may well find out several 1000 miles down the road.
 
#24 ·
I'll throw it on the alignment rack tomorrow and compare that to the alignment I did last week before the bushings. I'm not saying you are completely wrong, that's just just how I've always known the front ends of these cars to be affected with offset bushings, e30,e36 etc.
 
#25 ·
Older, American built cars that had upper and lower control arms or torsion bar suspension had adjustable CASTER as well as CAMBER and Toe. Once the McPherson strut came on the scene, CASTER has been built in and NON-ADUJSTABLE, the front shock/strut towers are built such that the angle is included and the lower control arms and mounting points are made to go a long with that pre-determined and non-adjustable angle to give an overall good CASTER Angel to fit the average driver.
A car with front strut suspension WILL have the CASTER affected if the shock/strut tower(s) are damaged.
 
#26 · (Edited)
I can't believe what I just read.
Tomoyer,, I recommend you do a little experiment next time you have your car in the air: remove the control arm bushing bracket bolts, dislodge the bracket from the subframe, grab the control arm at the bushing, move the arm inward towards the centerline of the car while watching how the outer control arm ball joint reacts. The caster changes before your very eyes. Also I would like to reference E30 325I control arm bushings compared to E30 M3 control arm bushings, the affect on caster is visible. Know your facts. End of rant.
I would also like to add that your are correct, about adjusting caster at the strut mount, but control arm bushings also affect caster.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top