33 GTR Broken front wheel knuckle

[believer]

Hi guy. My front wheel knuckle broke on me just before I hit the track. It’s where the tie rod bolts onto the knuckle. I do have bump steer rose joint tie rod ends but I didn’t hit anything and I do not climb ripple strips on the track, it snapped off when I was doing a three point turn in the carpark. 
Has anyone had the same experience?  This is my second one in two years but in the other side. The car has extremely low kms and it’s only tracked 3-4 times a year. 
Any thought??

 

[Duncan]

We have a lot of posts on SAU from over the years, I've never seen an upright snapped at the steering arm.

 

[GTSBoy]

The fracture pattern shows the force was a moment applied in the vertical plane (ie, the outer end of the steering up was being pushed up or down). I guess up from a cursory inspection.

This would suggest one of a couple of things.

1. Bad day at the foundry. I consider this unlikely, because I would consider it unlikely that both the left and right uprights on your car were made on a single or very rare bad day. Far more likely to come from different days, and therefore there should be many more reports of these failures.
2. The people designing these bump correction tie rods are not considering the change in direction that forces are applied to the steering arms. Again it would seem unlikely as there should probably be more reports, and the steering arms are approximately square in cross section.
3. You have been hitting things with the bottom end of them.

Or a combo of all three? Plus other possibilities/factors?

[Dasmbo]

Never seen this happen twice i would guess parts taken beyond manufactures specks if it were me i would have the next knuckle joint shot peened to try and make it stronger just like you would have your con rods shot peened 

good luck with it

[hardsteppa]

I had this happen earlier this year. R33 gtst, different knuckle but same failure.

[R32 TT]

Just had this happen to me too.  R32 GTR.   Also broke "just before going out onto the track" - someone up there is looking out for us...

Very scary since I was about to do a narrow street course with zero run-off and curbs everywhere.

Many people on here upgrading to billet uprights and R35 bearings?   Or buying new OEM knuckles? 

I am not keen to replace with another s/h 30 year old fatigued part.

[Duncan]

Interesting. I still think they are the result of impact damage somewhere along the line, but clearly lightning has stuck thrice!

I've still got the original ones on my race car and they have had some hard work.

[R32 TT]

Yep - well I do more tarmac rally sprints and a little bit of circuit.   It hasn't had any direct hits in the 20 years I've had the car - other than one or two 'bad bumps' and a curb but that was in the correct direction - ie wheel hitting it rolling, so tyre and spring took most of the impact.

Definitely sends a chill up your spine though...  

[GTSBoy]

I am starting to think that it has to do with the tie rod correctors. The forces between the tie rod and the steering arm are supposed to be close together (in the vertical direction). Spacing the tie rods down adds in a larger amount of torque, from the force being applied further away (ie, further down) and it appears that the casting will sometimes just say, "nope".

[R32 TT]

I have been wondering the same thing.  Ikeya Formula here.

Add A050's and they are under a lot more strain than stock - plus that lever as you point out.

Still you'd think you'd hear more about it.

 

[Dose Pipe Sutututu]

I saw on your IG page!

Mate, how lucky are you - go buy the lotto.

[Dose Pipe Sutututu]

I'm good at suggesting things that cost more than what they should.

https://www.brypar.com/shop/prime-r/prime-r-uprights/nissan-skyline-r32-34-gtr-front-upright/

 

[R32 TT]

haha yeah those or the KiwiCNC ones..    but I need to go buy that lotto ticket you mentioned (and win) to afford them.

They do seem like a really good thing though - especially with the R35 bearing upgrade.

[MBS206]

On 23/09/2025 at 11:16 AM, R32 TT said:

haha yeah those or the KiwiCNC ones..    but I need to go buy that lotto ticket you mentioned (and win) to afford them.

They do seem like a really good thing though - especially with the R35 bearing upgrade.

Except all that twisting force that is breaking a cast piece, appears to be going through 4 bolts in the picture Johnny posted of the BryPar one...

[R32 TT]

55 minutes ago, MBS206 said:

Except all that twisting force that is breaking a cast piece, appears to be going through 4 bolts in the picture Johnny posted of the BryPar one...

Those bolts would be orders of magnitude stronger that cast aluminium though.  And its mainly clamping force, not shear they are dealing with?

[GTSBoy]

57 minutes ago, MBS206 said:

Except all that twisting force that is breaking a cast piece, appears to be going through 4 bolts in the picture Johnny posted of the BryPar one...

That's probably OK. That's a face to face compression joint between two surfaces with the clamping load provided by those bolts. So.... it's unlikely that the bolts will end up feeling that load in shear, unless the clamping surfaces are not large enough, bolts not got enough tension on them, etc etc to prevent the two faces from moving wrt each other. Which... I would hope the designers have considered, seeing as it's probably one of the most important things the upright has to do apart from resist collapsing in its own right.

But yes, it would definitely be worth asking them what their safety factor on that part of the design was.

I tend to think that the casting, being a casting, is not necessarily the strongest bit of material in the world. It's about an inch square, and when you think about the loads that are being put into it, you have to wonder what safety factor the Nissan boys (and every other OEM engineer who has designed all the millions of other uprights that look essentially the same) used to account for defective casting, aging, severe impacts on the wheel, etc etc.