Common failure no, but not unheard of. It is frequent enough that there are a few “upgrade” pieces out there including a factory Nismo component. I don’t think the clutch/fasteners to be the root cause, however definitely variables that did not aid it any. The shaft was likely damaged during installation by hanging the weight of the gearbox of the shaft and/or jostling the box around hard to get the splines engadged. That more than likely induced a fracture, which was stressed by the bellhousing flex(loose/missing hardware) and a solid hub, triple plate sintered clutch. That’s a DAMN brutal clutch in any tranny. An 8.5" disk triple plate of above fashion can hold in excess of 1300ftlbs. A 5.5" organic button clutch is brutal enough in that triple setup…
Two stressful events occur using this clutch. One is upon installation of the splined shaft into the clutch plates. The inclination that can be introduced to the input shaft before it starts to bend is far smaller than that of a single or twin plate disk as the free play of the splines decrease dramatically in multiplate setups due to the increase surface area covered by the disk splines themselves. #2 is the decreased spline length of the shaft due to the amount of space taken up by the increased number of clutch plates. Instead of the shaft having roughly 1" of open spline between the clutch plates and fillet that can wrap up and absorb some torsional shock load, that distance was reduced to less than .4" and the load was being applied to a far smaller surface area that could not take the shock. Introduce a fracture or stress riser into the mix and failure is inevitable.
There is nothing you will be able to visually inspect by naked eye other than a torsion shear. The face of the fractures were subjected to sub 9000rpm, high pressure galling and have destroyed any visual aspect of the break other than subjective spline deformation beyond both ends. I will magnaflux and x-ray the shaft pieces at my shop, as will I do the same to most of the adjacent internal components to determine any other located damaged as a result of this failure.
And ditch the ETS-Pro…forgettaboutit!!! :lol It’s THE AWD system to run, I’d take it over Porsche shit anyday. AWD traction, RWD handling and power delivery. Best of both worlds.
Pull clutch yes.
The GTS tranmissions are very simple, this GTR gearbox is a little different inside. They’re also set quite a bit apart in price as well so I’m going to rebuild the existing box here, vs buying another used box and play with fate on what it may hold. I think that’ll make Cossey sleep a little better about it, or at least as good as he can anyway.
Car has a little more that 350hp, but nowhere even close to what requires this clutch. I believe this to be a case of non-informed owner dropping car of at shop and writing blank check to have work done. Shop installed the most re-donk-ulous clutch they could get in, which didn’t suit the car or driver at all. Rest is water under the bridge as they say.