Adjustment instructions for Koni struts?

[kmead]

Good day all.

As the Koni struts I have came off a car in a boneyard back in the early 1990s, I don't have instructions on how to adjust them.

These are the instructions I found on the Koni website.
Are these correct for our old struts? Does anyone have the original directions for how to properly adjust them and if there is any info on what firmness or however Koni describes each step in the adjustment range? IE Full soft, 25, 50, 75, full hard? (my assumption given there are five steps).

Thanks, just wanted to verify before I start fiddling around.

Karl

Adjustment Procedure 76, 80, 82, 86, 87, 88, 90, 8040, 8240 Series

Rebound Adjustment Procedures

1. Remove the shock absorber from the vehicle and hold it vertically with the lower eye or pin attached in a vise. Use clamp plates to prevent damage.
2. Fully collapse the shock absorber, at the same time turning the dust cap or piston rod slowly to the left (counterclockwise), until it is felt that the cams of the adjustment nut engage in the recesses of the foot valve assembly.
3. Some shock absorbers include a bump rubber concealed under the dust cover and it must be removed prior to adjusting.
4. The damper may have already been adjusted. Therefore check whether the shock absorber is in the adjustment position or not by keeping it collapsed and gently turning it further to the left counting at the same time the half turns until a stop is felt. Stop turning then and do not use force.
5. Keeping the shock absorber collapsed, make 1 half turn (180 degrees) to the right (clockwise). In case of prior adjustment add the number of half the turns previously found. The total range is about 5 half turns.
6. Pull the shock absorber out vertically without turning for at least 1 cm to disengage the adjusting mechanism. The dust cap or piston rod may now be turned freely.

 

[Dr.Jeff]

That is the same technique for ours. Basically compress them fully so the end of the main rod engages with a slot on the valve body at the bottom end. As you rotate the top of the rod (while holding downward tension) you will feel when it drops another couple mm into the slot. You might have to remove the bump-stop to get it far enough collapsed. Then you can rotate it in either direction; clockwise for softer, CCC for firmer. Some models do not "click" in particular positions, they are infinite. Actually even the ones that do "click" are infinite if you leave it between clicks. Once you have set the position, raise the main rod back up enough to clear the bottom slot (a couple mm). Under normal use they do not collapse far enough to make contact so the adjustment stays where you left it. Koni offers a very vague idea of 'soft' to 'hard' but it isn't specific. The adjustment is fairly linear and you can feel a significant difference when you manually extend the rod. There is about 1-3/4 turns of adjustment (varies with different models and from shock to shock).

Here are some visuals:
The blue arrow tabs (first pic) need to engage with the yellow arrow slots (second pic) in order to make adjustments...

For a little more insight see this thread:
https://xwebforums.com/forum/index.php?threads/suspension-koni-strut-servicing.36142/#post-314591

EDIT: I just corrected the direction of adjustment from my initial entry. CC is soft, CCC is firm.

 

[Dr.Jeff]

Here is a little more info on it.

First, I just corrected my last post about the direction of adjustment. So reread that if you saw it before my edit.

Second, here is a rough graph of the adjustment curve as given by Koni. I'm not sure how accurate it is, the whole thing isn't to scientific. Basically there's a stack of small discs in the valve. When you rotate the vave (with the end of the main rod), you are screwing that stack of discs closer together or further apart from one another. That alters the ease at which the fluid can pass through the stack.

 

[kmead]

Thanks.

I will likely start out with full soft on the fronts and when or if I can do the rears I will adjust accordingly.

The X has been in the garage since December, this spring the roads are abysmal and my rubber strut mounts are massively deformed such that the rings at the top are hitting the steel of the strut tower. I have some SS doublers courtesy of the originator and will use those and new mounts when I can get at the car and the parts.

Expecting snow tonight so it won’t get done today or tomorrow...

 

[Dr.Jeff]

Before you mount them, try compressing and extending them manually off the car. The adjustment only affects the extension (rebound), so compare the resistance of the compression to that of the rebound. You typically want noticeably more rebound. With them in the full soft position the rebound may feel equal to, or even slightly softer than the compression. If that graph (posted earlier) is at all accurate, then you can see why. From the lower end of the curve (full soft) it first rises exponentially for a bit before leveling out to more of a linear rise.

Also these Konis are valved relatively soft overall. They were intended for regular street use on a stock car, not a performance set-up. Especially the later production ones. Furthermore Koni started out using hydraulic fluid around a 30 wt, but later went thinner and thinner until they eventually had close to 5 wt. That's a pretty big change. I could not get an answer why the change, but experimenting with mine I ended up putting a 30 wt in (even 20 wt felt too soft for me). So you may end up a little closer to mid range in the setting.

And be aware, when you first try to compress and extend the strut it will seem very easy to move. But after a couple of pumps it will get much stiffer. When they sit unused the fluid settles out of the valves. Especially if they sat on their side, the air pocket travels to the lower end where normally only fluid lives. So cycle them a few complete strokes of full range before assessing anything.

 

[Chad C.]

My god, Karl... SNOW? Oregon is a fickle state for weather but we have leaves on the trees, and I've got a sunburn from some hours spent on the riding mower. I wish you an end to cold soon!