KONI Sports for Classic Z's

[Zed Head]

I have read about this same thing happening.  I think it's on the site somewhere.  Search around.  I'll post it if I find it.

Found it -

 

Edited April 7, 2021 by Zed Head

[madkaw]

I believe this was mentioned by someone else in this thread . I decided not to use their supplied nut for that reason of seizing 

[lapriser]

24 minutes ago, madkaw said:

I believe this was mentioned by someone else in this thread . I decided not to use their supplied nut for that reason of seizing 

You are right, I see it now on page 7. I thought I read through the thread fully but it's possible I read through a different thread somewhere else or browsed through this one too quickly. Thanks for the heads up.

[Zed Head]

@KONI Lee @Joseph@TheZStore @James@TheZStore

Just notifying the guys that should know.  

[Joseph@TheZStore]

24 minutes ago, Zed Head said:

@KONI Lee @Joseph@TheZStore @James@TheZStore

Just notifying the guys that should know.  

Thanks Zed, always appreciate you looping us in. Lee already knew, as Koni has been conversing with this customer directly this week. Lee himself will be in soon with a direct response. James is on a leave of absence, which is why there haven't been any responses from him for a while.

Thanks again!

[KONI Lee]

Actually Joseph and I have been talking on the phone about this during recent posts.  Lapriser had as also reached out to our KONI tech staff at info@koni-na.com, which is what we would prefer that you do if you have a technical issue such as this.  I also saw the post notification when it popped up on the forum.

First off, clearly I am sorry to see of the issue that had occurred with the stripping of the threads during installation.  We (KONI and Motorsport Ind.) have already made a plan to get a new replacement unit sent out to lapriser at no charge listed officially as a "customer courtesy" replacement due to an installation error that hopefully we can all use a teaching/ learning example and not actually as a warranty situation caused by a product manufacturing issue.  

Looking at the photo, it is pretty clear that the nut was not cross threaded from the beginning as the threads are only truly destroyed down in the area where the nut sits in the tightened position.   The instructions state that the nut should only be tightened to 37 ft./lbs. which is where we feel that things went wrong here. Normally we only see issues of mounting threads being stripped in place (it is quite uncommon though) when someone uses an air or electric impact tool and bangs away to a much higher torque and also gets the very common side effect that the damping adjuster tab and mechanism also gets jammed from the hammering effect of the impact tool.  Although the adjuster did get stuck in this case, lapriser did state that he had only used hand tools so must have been solely from manually tightening to much greater number than recommended.  Of particular note, the top mounting threads used by the Z cars are use  D -shape on the quite small in diameter (12mm vs most strut mount threads at 14mm) with a pretty fine thread 1.25 pitch.  The flat area of the D means that about 25% of the circumference has no threading which will also mean that there a not a lot of threads available to hold excess torque without damaging the threads.  The D -shape is required by Datsun's upper mount shape which was not uncommon in the 1960s and 1970s but went away for the vast majority of cars after that and now 360 degree threads are the norm for several decades.  Extra care should be used if you are installing the D - shaped mounting pins in a spherical bearing camber plate as well that doesn't have the D -shaped mounting hole.

Laprise did make the comment that the insert appears to no longer be damping now which is probably evidence that difficult and escalating process of getting the thread damaged nut and mount separated had also cause the strut's piston to become untorqued  and open up or bypass the valving flow paths.  Normally we only see this when someone uses and impact tool and it aggressively spins the piston rod inside the body or it the car has experienced very high side loading force or top mount bearing failure under use.

So we will make sure that we get a fresh units to laprise for his car but would very much like to caution people during installation to be careful and be aware of the following:

• Use only hand tools and not impact tools as you can overtighten and cause internal issues that you may not notice at that time
• Use only 37 ft/lbs when tightening the top nuts .  If you don't have a torque wrench available, better to be ion the conservative side than the too aggressive side
• The Z car's 50 year old top mounts require a small diameter, fine thread and a D shape top mounting area with about 25% of the circumference having no threads so again, please do not overtorque it or you can damage the threads and have a tough time getting it back apart.
• The provided nyloc nut is there to hold the mount properly tighten and not loosen so there is no need to tighten beyond the recommended amount.  Earlier in this thread someone projected that the KONI nyloc nuts were made of stainless steel and the cause for galling but that is incorrect.  The KONI nuts are actually chrome plated mild steel and not stainless (much more expensive and not used in damper hardware) so dissimilar metals of different hardness is not an issue here. 

Sorry for this being long but I am trying to be thorough with the explanation.

[lapriser]

@KONI Lee @Joseph@TheZStore

Thank you for your responses and I appreciate the comprehensive explanation. I will be sure to be more cautious when installing the next ones and am super excited to get these installed and on the road. These seem like genuinely good products and though this instance is unfortunate hopefully it at least helps prevent something similar from happening to someone else.

Thank you, again, for your response.

[gundee]

On 10/17/2020 at 5:01 PM, madkaw said:

Here’s my remedy - I don’t recommend this to anyone as a disclaimer . 
You will notice the one pic showing the distinct bulge from the weld bead . The fit is so tight that it makes a difference . I’ve grinded enough welds to feel confident for myself - but won’t tell anyone this is the fix . Even with this “fix” the cartridge still stands tall in the housing . 
 

Koni always had this issue from the start with 240Z's. I have a set of Koni 'reds" from 35+ years ago and we did the exact same thing to fit them.

They are that tight. If I were Koni I would make them a wee bit shorter to make up for the welds on the bottom.

[lapriser]

Hey guys,

I was thinking about drawing up some Datsun Specific instructions for these. Is that something anyone would be interested in? I started modeling some reference 3D files for my own sake. Can anyone confirm this is the stack up for the fronts?

 

Edited April 9, 2021 by lapriser

[AK260]

Utterly brilliant chap - massively applauded!!


Yes it is but don’t forget the white washer that goes at the bottom to stop air locking if bottomed out.

[lapriser]

9 minutes ago, AK260 said:

Utterly brilliant chap - massively applauded!!


Yes it is but don’t forget the white washer that goes at the bottom to stop air locking if bottomed out.

Updated with another screenshot. Thank you!

[gundee]

32 minutes ago, AK260 said:

Utterly brilliant chap - massively applauded!!


Yes it is but don’t forget the white washer that goes at the bottom to stop air locking if bottomed out.

Where did you get that idea? That is not what the washer is for.