Adjustable Front Strut

Jan Gullett

Jan Gullett

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My old bilsteins are sticking & I have an odd noise on speed bumps in one front strut. And if memory serves, some of the rubber dates from 1974. So time to redo these with new rubber and shocks. I have checked the sheet metal and don't see any cracks or evidence of weakness. These received a through redo when the car was restored (more than fifteen years ago now, but it seems like yesterday) so I think am structurally OK.

When preparing to order parts, I noticed my coupe has a pair of adjustable struts with a large round nut on threads below the spring perch to adjust them. Does anyone have any ideas on how to properly adjust these? I assume they are primarily for ride height adjustment? If my memory serves, a coupe fan produced a limited run of these for the community years ago but I don't know how to properly adjust them.

Perhaps related, camber alignment has always been off on this car. I know it has Carl's lowered springs and heavy duty sway bars. So I was going to move to adjustable camber plates so the alignment could be brought into spec. Does anyone have thoughts on Carl's fixed units versus the adjustables from Bav Auto? I presume these will work with my strut bar (best investment I ever made in my coupe, followed closely by the rear strut bar)

I love the handling as is so would rather not change ride height. So I was going to replace my shocks (I think they are the Bilstein comfort versions which are no longer available I guess) with new Sport versions. Any other suggestions?
 
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I put Sport Bilsteins a couple of years ago and they are not too hard. I read that harder shock can cause damage to the towers. I do not think I have an adjustment on mine.
 
Jan Gullett said:
My old bilsteins are sticking & I have an odd noise on speed bumps in one front strut. And if memory serves, some of the rubber dates from 1974. So time to redo these with new rubber and shocks. I have checked the sheet metal and don't see any cracks or evidence of weakness. These received a through redo when the car was restored (more than fifteen years ago now, but it seems like yesterday) so I think am structurally OK.
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Sticking? If the struts are not rebounding, or actually bind through otherwise normal travel, then replacement or rebuilding are certainly indicated. But the noise may indicate something entirely different.

When considering noise and camber issues on any particular corner, my first inclination might be to examine both the upper (usually rubber) strut mount and the control arm and strut rod bushings (and ball joints). If the rubber is deformed, or no longer pliant, it can result in strange camber settings. If the upper mount is worn or loose, it too, can result in suspension geometry changes and can make "odd" noises when compressing or expanding. Of course odd noise can also be caused by extremely loose: lug nuts, wheel bearings and anything that is part of the steering linkage. And let's not forget sway bar links. If loose or worn - they can make their presence known too.

If you are not familiar with what you have in the way of adjustable struts, you might consider posting a picture or two, and perhaps someone frequenting this board can fill in some of the blanks. It may be too much to ask after so much time has passed, but have you tried contacting the original installer for some of this information?

hth


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Carl's fixed camber plates work well with the springs he sells. They mount on top of the strut, but under the body, so you should have no issues with the strut bar.

I'd also like to see the adjustable strut body. Sounds interesting.
 
Adjustable Strut

The struts in my car came from Paul Cain. He manufactured these in January 1996. They were the subject of an article in the CS Register (Vol XI, No. 2, Pg. 14). These can be adjusted without removing them from the car.

The struts stick only on first bounce. They seem to be slightly stuck in place until you hit the first bump then they work fine. I was told that this was likely due to old rubber in the shocks which breaks loose and warms up on first bump then work fine until the car sits and the rubber cools, causing them to slightly stick again. Since the shocks are more than fifteen years old, it probably makes sense to replace them.

I have had a long term tire wear problem on the inside edge of the front tires, which I have dealt with by rotating tires and buying new ones. But since I plan to dissemble the struts, I thought this might be a good time to address alignment issues. My camber is out of spec. I have -0.6 degree front left and -0.8 degree front right. I believe the spec is +0.0 to +1.0 degree. I run toe of 0.11 degree versus recommended 0.05 to 0.08 to compensate for the camber. Cross caster is also out of spec at 8.5 degrees right and 7.7 degrees left. Adjustable plates would solve this. I would normally prefer Carl's fixed plates but I don't know that my alignment would be right given the combination of Carl's lowered springs and adjustable front struts.

The noise I have on bumps seems clearly related to the driver's side strut. I recently had the lower control arms, ball joints and radial control arm bushings replaced and the pros that did the work also felt the noise was in the strut. I don't think it is steering related since it does not vary with steering angle or steering use. Sway bar bushings seem to be tight. I don't think this noise is related to the sticking of the shocks because it continues after first bump. My theories are old rubber around the strut support bearing (it looks fine and centered but is more than fifteen years old), a loose screw ring allowing the shock to move in the strut, or movement of the lower spring perch which was modified to be adustable by Paul. It takes a pretty significant bump to cause the sound, but is only on the driver's side. It sounds like the shock nut is loose at the top of the support bearing but I checked this. These shocks are not in oil like the OEM installation if that makes a difference. I have had this noise for a while but is seems to be gradually worsening.

So my plan is to install the Bilstein sports given the lower than standard ride height, replace all of the rubber in the strut and add modified or adjustable camber plates to correct the alignment. I would normally go with Carl's fixed units, but not sure they would correct the camber since I do not know where I stand on ride height given the combination of Carl's springs and the adjustable struts. I would also adjust the struts but don't know what specification to target on ride height or how exactly to set these. Plus the coupe may have other issues given it's age and typcial body flex. But if I knew how to properly adjust the struts, I might go with Carl's fixed plates, since I assume the Bav Auto plates have less flex and may create more normal bump "thump" noise. Any comments on the Bav Auto camber plates would be appreciated (along with any other suggestions).
 

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You definitely couldn't use Carl's fixed plates as you are already running negative camber, they would give you even more negative. Adjustable plates are needed, you should be close to zero or slightly positive.
 
One of the uses of adjustable struts is to "corner balance" the car. This is usually done with a scale under each wheel at either the front or back, so that the weight on each front or back corner is the same (or different if you have knowledge to set up a car for a particular situation/track).

Think of it this way: if one of the struts is too long, it will try a little harder to push up that corner of the car. This upsets the handling by putting more stress on that wheel. Thus, one wants to get right and left strut lengths set correctly so as to equalize the weight borne at each corner of the car. This works right-left, not front-back.

If you find this is obvious, 'scuse me, but no one had addressed it yet.
 
MMercury,

question on those eibach coilovers. do those fit an e9? or are they for a different car.
 
MMercury said:

Photos were sourced from E36 board and used solely for illustrative purposes. To best of my knowledge E36 application only. (Eibach no. 52-12-1003-01) Sorry for any confusion.


http://forums.bimmerforums.com/forum/showthread.php?t=1604326
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thats ok ... just wanted to know if there was a serious application available for our cars that i wasn't familiar with. i have been looking to see if there were any setups to try to create a more modern suspension for our cars.
 
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