KONI Sports for Classic Z's

[Av8ferg]

This was a interesting read.  Lots of issues people have had.  I just installed mine and made a video to see if you all think I did this correct based on the posts here and to help future members.   FYI I used the stock gland nuts because the ones supplied with my shocks didn’t work.  Everytime I attempted to toque them down they’d slip.  The threads were clean and no cross threads.  The stock ones worked fine but I only torqued to 70lbs because I was getting nervous about breaking something with any more force.  

 

[Zed Head]

11 hours ago, Av8ferg said:

FYI I used the stock gland nuts because the ones supplied with my shocks didn’t work.  Everytime I attempted to toque them down they’d slip.

Koni put a lot of effort in to getting those gland nuts made.  Wonder what went wrong.  The gland nut is meant to center the shock body in the tube in addition to clamping it in to the bore of the strut tube.

@KONI Lee @Joseph@TheZStore

[Joseph@TheZStore]

On 9/15/2021 at 7:09 AM, Av8ferg said:

I used the stock gland nuts because the ones supplied with my shocks didn’t work.  Everytime I attempted to toque them down they’d slip.  The threads were clean and no cross threads.  The stock ones worked fine but I only torqued to 70lbs because I was getting nervous about breaking something with any more force.  

 

Sorry you’ve had trouble. One manufacturer’s Strut Cartridges should not be used with another manufacturer’s Gland Nuts, so let’s see what we can figure out.

Which Gland Nut you used there doesn’t necessarily matter to what we’re trying to figure out here, but to cover all the bases, the one shown in your video is not an original Nissan 280Z Gland Nut. The original nuts had seals to keep the oil fill inside the shaft where the plunger rod was, and it would not fit down properly on top of the strut cartridge body (I was curious to see if we had an original Gland Nut here, and found one, so included images in case others wanted to see them).

When manufacturers started making physical strut cartridges to replace the original non-cartridge setup, they all included their own specific Gland Nuts, as they needed to match the shape of the top of the strut body. Just like with Koni, that Gland Nut is the exact inverse of the top of the strut body. Depending on what strut cartridge manufacturer made that Gland Nut, it may or may not be fitting well on top of the Koni strut body; which, if not, could allow strut cartridge movement and damage.

The only way that a Gland Nut could slip when tightening would be if they somehow were incorrect nuts (difficult to imagine, but not completely impossible that some random Koni application has Gland Nuts that are nearly identical but just slightly smaller, and were mistakenly put in the box), or if the threads are damaged on one side or the other (which you said the threads weren’t), or there is damage to one part or the other (even stress/wear/cracks/stretching/damage to the strut housing tube itself).

Also, in your video the top of the housing seems to be shiny clean as if machined somehow. It may not be relevant, but do you know what was done to the top of the housing tube there?

As far as the Gland Nuts you received, if you are able to measure them for us, knowing the exact dimensions and thread pitch/details would help us try to figure it out. Otherwise we could also just get those back here from you and confirm if they are correct. Since the Koni Gland Nut is the exact proper fit for the Koni Strut, then we should see what can be solved so that you can use Gland Nuts that hold the Strut Cartridge in the proper position.

Let us know.

(the first two images are of an original Nissan Gland Nut (with seal), and the third is the underside of the Koni Gland Nut shaped to fit the top of the Koni cartridge exactly)

[Av8ferg]

Joe, thanks for the post. Im overseas for work but can partly answer some of your questions. You are correct the gland nut I used wasn’t stock but the ones that I removed when replacing the old shock inserts. They were almost identical to the Koni’s except the number of threads. The Koni’s have about 1/2 the amount of threads that the ones I removed. The thread pitch was correct because I tested fitted the Koni gland nut prior to installing the shocks. When I put them on with the shocks, they would thread on fine but when I began hitting high torque values >50 they would pop and be loose again. Almost like they jumped a thread. It was very odd . It happened 3x I tried it and for fear of damage I decided they were unusable. Inspection of
The threads on the strut post those attempts showed no damage at all. There were marks on the top of the shock inserts where the gland nut was bottoming out. When I used the gland nut I previously removed from
The car they were able to bite more threads in the strut and thus not pop or jump threads at torque over >50 but I chose to stop at 70 ftlbs .
The silver ring you see at the top of my strut is a metal tape and a strip of flashing tape. They are there so that I didn’t damage the new powder coating on strut when installing the shocks in the gland nuts with the gland nut tool. There was no modifications to the strut. They’re were stripped with a blasting agent and powder coated.


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[Av8ferg]

OBTW...I think the instructions supplied with Koni’s are beyond terrible. I get what they’re trying to do. Have instructions that don’t required 15 different languages but it’s not a lot of work to make instructions for the 4-5 major languages in the world. When you get on forums all of the internet for people putting Koni’s in other cars the SAME Questions come up over and over again so obviously the instructions are terrible. So how about they fix them so they make sure the customers are happy with their product and confident they did it right. Just an idea?


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[gundee]

Here is the gland nut from the 1970's Red Koni's.  FWIW

[Joseph@TheZStore]

On 9/23/2021 at 6:28 AM, Av8ferg said:

Joe, thanks for the post. Im overseas for work but can partly answer some of your questions. You are correct the gland nut I used wasn’t stock but the ones that I removed when replacing the old shock inserts. They were almost identical to the Koni’s except the number of threads. The Koni’s have about 1/2 the amount of threads that the ones I removed. The thread pitch was correct because I tested fitted the Koni gland nut prior to installing the shocks. When I put them on with the shocks, they would thread on fine but when I began hitting high torque values >50 they would pop and be loose again. Almost like they jumped a thread. It was very odd . It happened 3x I tried it and for fear of damage I decided they were unusable. Inspection of
The threads on the strut post those attempts showed no damage at all. There were marks on the top of the shock inserts where the gland nut was bottoming out. When I used the gland nut I previously removed from
The car they were able to bite more threads in the strut and thus not pop or jump threads at torque over >50 but I chose to stop at 70 ftlbs .
The silver ring you see at the top of my strut is a metal tape and a strip of flashing tape. They are there so that I didn’t damage the new powder coating on strut when installing the shocks in the gland nuts with the gland nut tool. There was no modifications to the strut. They’re were stripped with a blasting agent and powder coated.


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John, let us know when you're back, and we'll go from there for Gland Nut measurements, and/or getting them back here. As far as the ones you used, as long as the ID of the inner opening that seats down on the strut matches extremely close to the top of the KONI, we would assume you'd be ok, but there may be factors we're not thinking of. If there is any movement at all, the damage could grow over time.

We'll figure it out.

[JagoBlitz]

Hello,

I just received the Koni dampers for the 280Z and just want to double-check the orientation of the sleeve (marked in yellow).
In the photo it look like the large diameter is at the bottom, but in the CAD-model it is the other way around.

How is it supposed to be?
Thank you very much.

Best regards from Germany,

JagoBlitz

[Joseph@TheZStore]

2 hours ago, JagoBlitz said:

Hello,

I just received the Koni dampers for the 280Z and just want to double-check the orientation of the sleeve (marked in yellow).
In the photo it look like the large diameter is at the bottom, but in the CAD-model it is the other way around.

How is it supposed to be?
Thank you very much.

Best regards from Germany,

JagoBlitz

 

You are exactly right, sorry about that, I had forgotten all about posting that previously. I blame 2020, lol...

Koni made this setup with the sleeve because that is the way they did it back in the early days. So for these struts, they copied that same setup. Koni told us that originally it was done that way as some coil over kits would not work with the diameter of the shaft, and they therefore chose the sleeve design so it could be optional if necessary for custom setups/coil overs/etc. (Koni always tries to think of racers as well as enthusiasts whenever possible).

When the image on the left was posted, we had queried Koni and they agreed that was a proper way to set it up, and will work fine that way. When our drafting-talented customer made the image on the right, we queried Koni again about it. They had the engineers (i.e. smart guys) go through it all again, and their final determination was that once the weight of the car is down on the setup, it matters not which direction the sleeve is placed, as it ends up functioning exactly the same while in actual use. So if you install/installed them with the "flange/ledge" at the bottom, all is well. If you install/installed them with the flange/ledge at the top, all is well. The smartest guys in the room determined that it makes no difference.

I'm sure people will add their own thoughts, which is part of what forums are great for. In our own non-engineering minds, having it with the ledge at the bottom might hold the bump stop (at least our urethane bump stops, which we recommend with these struts) in a bit more favorable position. At the same time, having the ledge at the top might work better with different bump stops, and to be extremely non-technical, "looks" better and more natural to us, and might make initial installing slightly easier due to the pre-compression height of the parts while installing (possibly useful if you have stubby fingers like I have).

But literally, direct from the Koni engineers, when it comes to how the strut assembly functions, the "ledge/flange" part of the sleeve is irrelevant as to position. Both are Koni engineer approved.

[jonathanrussell]

I agree that you can install the sleeve either way but I believe that the only right way to install is with the wide section of the sleeve at the top....as shown in the drawing above.

FIrst, the wide section of the sleeve gives the strut insulator a more firm surface to rest on.

Second, if you install the sleeve with the wide section down, the bump stop could get damaged and it seems like the strut would bottom out against the sleeve instead of the spring perch top.

J

Edited October 6, 2021 by jonathanrussell
clarify

[Joseph@TheZStore]

1 hour ago, jonathanrussell said:

I agree that you can install the sleeve either way but I believe that the only right way to install is with the wide section of the sleeve at the top....as shown in the drawing above.

FIrst, the wide section of the sleeve gives the strut insulator a more firm surface to rest on.

Second, if you install the sleeve with the wide section down, the bump stop could get damaged and it seems like the strut would bottom out against the sleeve instead of the spring perch top.

J

I can't speak for the Koni engineers (and I'm certainly not one, lol), but as best as we understand it:

The strut insulator does not impact on the Koni sleeve either way it is installed. The insulator impacts on the strut bearing in the front (or the strut spacer in the rear), and they in turn impact on the top of the spring seat. The Koni sleeve sits slightly under the top of the bearing or spacer (otherwise it would grind when you make a turn), and is not impacted.

The bump stops were originally bonded to the underside of the spring seat. If you bottom out, the bump stop takes the impact between the strut body (Gland nut) and the upper spring seat, the Koni sleeve is in-between and isn't impacted either way.

As far as damage to the bump stop, that is an engineer question for sure, but it *seems* like the only time there is pressure on the bump stop is when it bottoms out, and then all the stress is between the top of the bump stop and the spring seat, and the bottom of the bump stop and the Gland nut.

I'll try to get this discussion seen by those engineers to get their corrections/thoughts.

[jonathanrussell]

Thanks for the info.

So, I just stacked all of the parts (strut insulator, spacer, spring seat, bump stop) together....and then installed everything over the koni strut rod sleeve...which is installed at the top of the strut rod. I experimented with both ways to orient the sleeve.

The strut insulator gets bolted firmly against the top of the strut rod sleeve we are discussing.

The strut rod sleeve slides through the middle of the spacer OR bearing. I

So, I don't understand what you mean by your 2nd paragraph above.

With everything stacked together, if the wide portion of the koni strut rod sleeve is oriented downward, then it protrudes about 1/4 inch below the bottom of the spring seat.

Based on this, I doubt that the 1/4 protrusion would ever damage the bump stop.

I do now wonder whether the wide portion of the sleeve, if installed downward, could get hung up in the hole of the spring seat when installed on lowering springs, the car is lifted up, and full droop causes the spring seat to drop below the wide portion of the sleeve.

I also compared the parts with KYB and old Bilstein struts I have on hand. Both are the same diameter at the top where the threads end/start as the narrow portion of the Koni sleeve. And, both widen permanently at about the same spot where the wide portion of the Koni sleeve would rest if installed downward. The difference though is that if the wide portion of the koni sleeve is installed downward it kind of serves as something that the spring seat could get hung on as described above. 

So, for me, in balance, I think I will continue installing koni strut inserts with the wide portion of the sleeve on the top.