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Old 01-12-2013, 01:52 PM
vintage42's Avatar
vintage42 vintage42 is offline
BMW CCA 1405
Location: Louisville, KY
Join Date: Jun 2007
Posts: 3,760
Mein Auto: 1997 BMW Z3 1.9 5MT
I started not thinking that replacing struts affected alignment. Then when I saw the "camber bolt" and the slightly oval top holes in the strut mount, it seemed the struts could affect alignment.

But now that I am into replacing my struts, and have removed them, I can see that mine at least cannot affect alignment. The oval top hole is just to allow for variations in the holes in the strut and the steering arm, otherwise it could be impossible to get the new strut on.

The strut is bolted without possibility of movement to the steering arm by 3 bolts. The bottom two bolts alone would prevent any movement between strut and steering arm. If there is a "camber kit", it would probably consist of a new steering arm with slotted holes.

To quote from the Bentley Manual on alignment:
Page 310-4:
(After replacing struts) Have car professionally aligned when job is complete.
And what that means is explained on Page 320-5:
The front axle is aligned in relation to the rear axle, then the front wheels are aligned in relation on another. This is known as a four-wheel or thrust-axis alignment.... Front and rear caster and camber are both fixed by the design of the car. Any deviations are usually the result of worn or damaged suspension or body parts.
The only adjustment possible explained on Page 320-6:
Front Toe-In... is adjusted by altering the length of the outer tie rods.
So replacing struts cannot affect alignment, and the recommendation is to have the "car" aligned after strut replacement, which means a four-wheel back to front alignment. This should not be necessary unless damage is suspected. If you take your Z3 for an alignment after replacing the struts, the shop can only check and adjust toe-in, which has nothing to do with the struts. I would only do that if the tires were wearing, cupping.

Edit: It was amazing how tight the two lower strut bolts were. It took all my strength on the end of a big torque wrench to back them out, and they resisted equally their entire length until the last few threads. It felt just like cross-threading. I know what 75 f-p feels like going in, so I estimate they took over 100 f-p to remove. The threads were OK but coated with pink cement, the remains of red LockTite. Most could be wire-brushed out, but I understand why new bolts are recommended: the old bolts were probably overstressed by removal and clean threads are needed to make room for new LockTite.

Last edited by vintage42; 01-13-2013 at 08:33 AM.
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