In a recent discussion about safety measures, a friend pointed out that the Tension rods on the Z tend to snap, espepcially on lowered cars with hard bushings, as the tension gets too high.
You can either switch to an adjustable tension rod kit, or as an alternative, use an Oldschool Bearing kit, which allows the T/C (Tension Compression Rod) to have a slight movement and therefore reduced tension. Today i got one of those kits.


This kit is an vintage NOS item which was made by Kontrolle Automotive products in the USA.

But i think they were made by different manufacturers and MSA still has them on sale new. Allthough they currently don't ship to switzerland:
https://www.thezstore.com/product/6551/tension-rod-tc-kit-70-887-zzx

At one point even Nissan USA sold them under the Part number 99996-TKIT as shown below in the 1998 Nissan USA Motorosports catalogue:
The part number indicates that it was not a product from the Nissan HQ, but a local market item by Nussan USA only. and i guess it was sourced from one of those suppliers like Kontrolle.
   

Here is the full installation manual:

And here an' illustration of the assembly that goes over the TC-rod instead of one of the bushings:

6 hours ago, JDMjunkies.ch said:

In a recent discussion about safety measures, a friend pointed out that the Tension rods on the Z tend to snap, espepcially on lowered cars with hard bushings, as the tension gets too high.
You can either switch to an adjustable tension rod kit, or as an alternative, use an Oldschool Bearing kit, which allows the T/C (Tension Compression Rod) to have a slight movement and therefore reduced tension. Today i got one of those kits.
 

I bought one of those kits from MSA years ago and installed them, I used the included metal C for the measurement, 2 yrs later the white nylon bushings were split and cracked.

I don't know if I got a set from a bad batch or what but I just went back to rubber on both sides.

By the way if you ever need help shipping stuff to Switzerland, pm me. If I can help, I  will

C

9 hours ago, grannyknot said:

I bought one of those kits from MSA years ago and installed them, I used the included metal C for the measurement, 2 yrs later the white nylon bushings were split and cracked.

I don't know if I got a set from a bad batch or what but I just went back to rubber on both sides.

Hmm, i was wondering how strong it is and how long it lasts. Let's see i might give it a try anyway. Were the ones from MSA from the same manufacturer? (Kontrolle Automotive in Fremont, CA)?
 

1 hour ago, Patcon said:

By the way if you ever need help shipping stuff to Switzerland, pm me. If I can help, I  will

C

thanks mate for your support! I have a forwarding address in the US, but it just wasn't worth the effort in this case. but will happily come back to you if i ever need this in future. Thank you!

13 hours ago, grannyknot said:

I bought one of those kits from MSA years ago and installed them, I used the included metal C for the measurement, 2 yrs later the white nylon bushings were split and cracked.

I don't know if I got a set from a bad batch or what but I just went back to rubber on both sides.

Mine dit the same thing, and I DON'T drive it hard. Ended up making them out of HDPE from work. They have been in the car since 2014. The instructions look exactly like the ones I have in my map and I ordered them from MSA.

59 minutes ago, EuroDat said:

Mine dit the same thing, and I DON'T drive it hard. Ended up making them out of HDPE from work. They have been in the car since 2014. The instructions look exactly like the ones I have in my map and I ordered them from MSA.

Nice. you don't happen to have a spare set of HDPE for sale? Or manage to do another set? I'll happily pay for it and shipping of course.

48 minutes ago, JDMjunkies.ch said:

Nice. you don't happen to have a spare set of HDPE for sale? Or manage to do another set? I'll happily pay for it and shipping of course.

Ill have a look for the old one. I had one original still in good condition to copy from. If I can find it I can get some copies done, but it will take a couple of weeks because our machinist is on holiday, and we "untrained" engineers are not allowed to play in his workshop😁

On 8/4/2023 at 9:17 AM, JDMjunkies.ch said:

In a recent discussion about safety measures, a friend pointed out that the Tension rods on the Z tend to snap, espepcially on lowered cars with hard bushings, as the tension gets too high.
You can either switch to an adjustable tension rod kit, or as an alternative, use an Oldschool Bearing kit, which allows the T/C (Tension Compression Rod) to have a slight movement and therefore reduced tension. Today i got one of those kits.


This kit is an vintage NOS item which was made by Kontrolle Automotive products in the USA.

But i think they were made by different manufacturers and MSA still has them on sale new. Allthough they currently don't ship to switzerland:
https://www.thezstore.com/product/6551/tension-rod-tc-kit-70-887-zzx

At one point even Nissan USA sold them under the Part number 99996-TKIT as shown below in the 1998 Nissan USA Motorosports catalogue:
The part number indicates that it was not a product from the Nissan HQ, but a local market item by Nussan USA only. and i guess it was sourced from one of those suppliers like Kontrolle.
   

Here is the full installation manual:

And here an' illustration of the assembly that goes over the TC-rod instead of one of the bushings:

Here's a version of that kit that I installed on my car somewhere around 48-50 years ago. Note that the pre-tension measuring gauge is made of fiberboard, not metal. I can't recall the source, but pretty sure it was not Nissan.

 

On 8/4/2023 at 7:17 AM, JDMjunkies.ch said:

the Tension rods on the Z tend to snap, espepcially on lowered cars with hard bushings, as the tension gets too high.

It's not increased tension (the rod is under compression during forward braking on the Z's), it's the side/bending load on the tip of the rod as the suspension moves that fatigues it.  The kit is supposed to allow the rod end to move around the pivot plane of the mounting plate area.  Looking at the parts in that picture it looks like the designer did not get the shape right on the combination of parts.  It's meant to move but the pivot point is extended out by the thickness of the aluminum cup.  And/or the hole in the aluminum cup is too small and the rod binds up as the angle changes, you can imagine it just by looking at the picture.  Seems like a person could/should just open up that hole and it would work like it was meant to.  Somebody messed up.

If you ever have the front end apart and want to see what happens, leave the rod disconnected from the control arm and move it through the range of motion it would see while the suspension moves.

And Delrin is a polyacetal (polyoxymethylene) not polyethylene.  It's known for dimensional stability but apparently not so good under high loads.  Could also be poor molding if it was injection molded.  It's used often for small gears and things like that.

Just some thoughts/observations/opinions.  I broke a rod after installing PU bushings.  Had a month or two of creaking and groaning over uneven ground to think about it before it popped.

On 8/5/2023 at 2:39 PM, EuroDat said:

Ill have a look for the old one. I had one original still in good condition to copy from. If I can find it I can get some copies done, but it will take a couple of weeks because our machinist is on holiday, and we "untrained" engineers are not allowed to play in his workshop😁

Haha i know this kind of guys exactly 🙂
Let me know if you need any measurements or photos of the original ones.

 

19 hours ago, Zed Head said:

It's not increased tension (the rod is under compression during forward braking on the Z's), it's the side/bending load on the tip of the rod as the suspension moves that fatigues it.  The kit is supposed to allow the rod end to move around the pivot plane of the mounting plate area.  Looking at the parts in that picture it looks like the designer did not get the shape right on the combination of parts.  It's meant to move but the pivot point is extended out by the thickness of the aluminum cup.  And/or the hole in the aluminum cup is too small and the rod binds up as the angle changes, you can imagine it just by looking at the picture.  Seems like a person could/should just open up that hole and it would work like it was meant to.  Somebody messed up.

If you ever have the front end apart and want to see what happens, leave the rod disconnected from the control arm and move it through the range of motion it would see while the suspension moves.

And Delrin is a polyacetal (polyoxymethylene) not polyethylene.  It's known for dimensional stability but apparently not so good under high loads.  Could also be poor molding if it was injection molded.  It's used often for small gears and things like that.

Just some thoughts/observations/opinions.  I broke a rod after installing PU bushings.  Had a month or two of creaking and groaning over uneven ground to think about it before it popped.

Thanks for your useful inputs. I Appreciate your thoughts. might think about widening the hole a bit on the aluminum base thingy.

The other option is a harder aftermarket polyurethane bush one side, a OEM one the other. Give a better feel, but without putting the rod under undue force.

Here is the one I bought in 1984 and have not used yet. It is supplied by Interpart. The plastic pivots are a hard black material.