Z3 Front Struts/Alignment

I'm planning to put front struts in my 98 Z3 2.8 this winter. Probably Bilstein Touring. Removing and reinstalling the struts shouldn't be a problem and I have a local shop that with a spring compressor that will help me out. The Bentley manual advises an alignment after strut replacement but it also says that the alignment is not adjustable other than toe. I currently have no alignment issues, the car handles great. Do I really need to have an alignment done after replacing the struts?

Thanks in advance for your advice.

The three mounting holes in the bottom of the strut are not slotted so I don't see how changing a strut could affect alighment.

I just put the bilstein touring shocks on my car. I'm happy with them. I am planning on getting an alignment.

Originally Posted by briano72

I just put the bilstein touring shocks on my car. I'm happy with them. I am planning on getting an alignment.

Do you think installing the shocks somehow changed the alignment?

Originally Posted by vintage42

The three mounting holes in the bottom of the strut are not slotted so I don't see how changing a strut could affect alighment.

I agree. I think after the strut change I will drive it for a while and see if I can detect a difference. I was just wondering what kind of experience other members of the forum have had.

Originally Posted by Dheilman

I agree. I think after the strut change I will drive it for a while and see if I can detect a difference. I was just wondering what kind of experience other members of the forum have had.

Yes, you must get an alignment. There is adjustment on the strut that will change your alignment, camber IIRC. Both my cars were out of alignment after front strut changes. If you only change the rear shocks, an alignment is not necessary as there are not any adjustments to be made on a stock car.

Ditto on Wertles comments. I have also slotted the top mount hole on the strut to give me more flexibility to remove excessive camber. I used aluminum to shim between the strut housing and spindle to insure it did not slip back.

One question for the gurus, which I'm sure that has been addressed before. When doing the alignment on the Z, do you need to have the 150# in each seat and weight in the trunk typical to checking the ride height? Thanx in advance for your sharing of knowledge.

Originally Posted by smayo964

One question for the gurus, which I'm sure that has been addressed before. When doing the alignment on the Z, do you need to have the 150# in each seat and weight in the trunk typical to checking the ride height? Thanx in advance for your sharing of knowledge.

150 lbs in trunk, 30 lbs in trunk, and a full tank of gas

See http://www.bimmerfest.com/forums/showthread.php?t=95521 for more details.

Originally Posted by Wertles

Yes, you must get an alignment. There is adjustment on the strut that will change your alignment, camber IIRC. Both my cars were out of alignment after front strut changes...

Did you change your struts yourself? And did you find slotted holes?
Or did you have a shop change your struts, they told you the alignment should be checked, so they did that, and found it was out?
Whatever they found, and whatever they did, I don't believe could be related to changing struts, because there is nothing disturb-able or adjustable in a strut change.
They could have found a pre-existing condition from hitting a curb or whatever, out of toe in or camber, but loosening and "adjusting" a strut's mount is not possible. There is no movement there (unless someone has slotted the holes).

Originally Posted by Wertles

... If you only change the rear shocks, an alignment is not necessary as there are not any adjustments to be made on a stock car.

I removed my rear shocks this morning to put on reinforcing plates. The point is not whether there are any rear adjustments to be made (there aren't), but that the shocks have no way of affecting alignment, any more than the struts.

Originally Posted by vintage42

Did you change your struts yourself? And did you find slotted holes?
Or did you have a shop change your struts, they told you the alignment should be checked, so they did that, and found it was out?
Whatever they found, and whatever they did, I don't believe could be related to changing struts, because there is nothing disturb-able or adjustable in a strut change.
They could have found a pre-existing condition from hitting a curb or whatever, out of toe in or camber, but loosening and "adjusting" a strut's mount is not possible. There is no movement there (unless someone has slotted the holes).

I changed all the struts (and shocks) myself on both my cars. The third bolt, the one that runs in the front to rear of the car on the bottom has adjustment. For anyone who doesnt believe me, go out, jack up your car, loosen that bolt and prove me wrong. This was for both my 99 M Coupe and the 02 Z3 roadster.

I have changed over front struts a few times and there is normally there is nothing to adjust on a Z3. BMW do sell a camber correction bolt, so if you see an eccentric bolt in there or some washers between the two lower bolts and the hub then an adjustment has been made at some time. If not then you are good to go

That said. For piece of mind I would always get an alignment check after changing major suspension parts. Better that than killing a tire in a few hundred miles.

Originally Posted by siwilson

That said. For piece of mind I would always get an alignment check after changing major suspension parts. Better that than killing a tire in a few hundred miles.

After the various responses, this makes the most sense......Thanks everyone.

Originally Posted by Wertles

I changed all the struts (and shocks) myself on both my cars. The third bolt, the one that runs in the front to rear of the car on the bottom has adjustment. For anyone who doesnt believe me, go out, jack up your car, loosen that bolt and prove me wrong. This was for both my 99 M Coupe and the 02 Z3 roadster.

This person did not find the third bolt adjustable:

Originally Posted by siwilson

I have changed over front struts a few times and there is normally there is nothing to adjust on a Z3. BMW do sell a camber correction bolt, so if you see an eccentric bolt in there or some washers between the two lower bolts and the hub then an adjustment has been made at some time. If not then you are good to go...

And this video does not show the third (or upper) bolt as being able to cause any adjustment, either. Starting at the 5:00 mark the bolt is inserted using a screwdriver aline the tight holes for it which allow no adjustable play.
http://www.youtube.com/watch?feature...&v=4l3rfGbxvlM

Perhaps your car has been modified so the hole for the upper bolt allows movement for adjustment of alignment.

Item 5 camber correction bolt. What you would normally use is called the fit bolt.

http://www.realoem.com/bmw/showparts...18&hg=31&fg=10

Originally Posted by siwilson

Item 5 camber correction bolt. What you would normally use is called the fit bolt.
http://www.realoem.com/bmw/showparts...18&hg=31&fg=10

RealOEM lists the same-named bolt for my 1997 1.9L. So I opened a box with a new Sensen strut to look at that third or top hole, and the hole(s) are slightly oval. So I now see that due to the range of movement in the oval, changing struts would most likely change the camber part of alignment. Especially if the holes in the car were also ovalized. The tie rods would adjust the toe-in part of alignment, but are not disturbed by strut replacement.


The APX Sensen video at http://www.youtube.com/watch?feature...&v=4l3rfGbxvlM on installing Z3 struts therefore has two omissions:
1. It does not mention the oval strut holes which affect camber.
2. The strut that is removed does not have a rubber bumper or plastic cover, which are necessary original equipment and fit together. The Z3 used for the video must have lost these in a previous strut replacement:
Bumper 31331092670
Protection tube 31331137932

Bilstein struts cannot use the OE bumper and cover, as they are designed to bump-stop internally and have an accordion cover.

I replaced the front struts on my Toyota Highlander. It to had camber correction bolts. What I did was mark the bolts and the struts with a marker so that I can reinstall them exactly as removed. I never did a realignment. I have over 60,000 miles and my tires are wearing beautifully. I would expect the same would hold true for the Z3.

Originally Posted by nfunk

I replaced the front struts on my Toyota Highlander. It to had camber correction bolts. What I did was mark the bolts and the struts with a marker so that I can reinstall them exactly as removed. I never did a realignment...

Did you replace the struts yourself?
Did the struts have oval top holes?
Why do you call your bolts "camber correction bolts"? Where did you see that term for your bolts?
What is the point of marking the bolts -- they just turn?
On the Z3 struts, the oval-ness of the holes is very small, maybe too small to mark. How oval were the holes on your Highlander?

Yes, I replaced them my self. If I remember there were two bolts that were cam shaped that when turned in the hole would adjust the camber. The reason for marking the bolts prior to removal was so that they would be exactly orientated the same when I install the new struts.

Originally Posted by vintage42

So I opened a box with a new Sensen strut to look at that third or top hole, and the hole(s) are slightly oval.

I have new Bilstiens on order and I will check them closely to see if they have the same.

Originally Posted by vintage42

... Bilstein struts cannot use the OE bumper and cover, as they are designed to bump-stop internally and have an accordion cover.

As more detail, I got that from Turner Motorsports after I raised the issue. Here is their email reply to me:
==========
I have contacted Bilstein directly and they said this shock does not require an additional bump stop as there is one internally built in to the shock absorber itself. That’s why the shock looks the way it does and the dust cover WOULD NOT accommodate the factory bump stop.
Thank you!
Jason Gannett
Sales Manager | Turner Motorsport
978-388-7769 x-137
/ // Parts and Performance for BMWs
www.turnermotorsport.com
==========

Originally Posted by nfunk

... there were two bolts that were cam shaped that when turned in the hole would adjust the camber. The reason for marking the bolts prior to removal was so that they would be exactly orientated the same when I install the new struts.

That explains why the Z3 bolts are specifically called camber bolts. They may not be not plain round bolts.
But I don't understand what may be two conflicting requirements of those bolts:
- They have to be tightened to a certain torque.
- But if they are eccentric, what if the required torque does not put their eccentricity at the right camber point?

I wonder if those camber bolts are round or eccentric?

I remember when I tightened the nuts I had to hold the bolt so that it would not rotate which would change the cam angle.

Originally Posted by vintage42

That explains why the Z3 bolts are specifically called camber bolts. They may not be not plain round bolts.
But I don't understand what may be two conflicting requirements of those bolts:
- They have to be tightened to a certain torque.
- But if they are eccentric, what if the required torque does not put their eccentricity at the right camber point?

I wonder if those camber bolts are round or eccentric?

Remember not all Z3s have the camber bolt. Most don't need it, they just use the standard 'fit bolt' which has no cam action, it's just a round bolt. Even if you have or need the camber correction bolt to make an adjustment torquing it up in the correct position is not difficult. just put a spanner on the head of the bolt to hold in place and a torque wrench on the nut.

BTW, the nut and the two lower bolts are one time use and not expensive.

Originally Posted by nfunk

I remember when I tightened the nuts I had to hold the bolt so that it would not rotate which would change the cam angle.

I see, turn the bolt until the camber is right again, then hold it there and tighten the nut.