Mmmm... now I'm at a cross roads ! I was about to contact Matthias to have 2 x conversions for mine a and a friends gearbox. I've had a lot to do with straight cut and performance gearboxes. If you hadn't told me anything about the background with ENGINRs failure, I would have said the incorrect oil has been used. I had a similar failure, albeit not a Mitsubishi box, using (manufacturer recommended) a high end full synthetic gear oil. We were given a replacement gear set and I took the advice of a top level, old school open wheeler Race engineer. We had no consequent failures. He had similar experiences with the Formula Holden Hewland gearboxes.... in the end , he used el cheapo "Trac Trans " oil. Put simply, Tractor auto trans oil. Castrol do it as " AgriPlus" now. It has a high level of friction modifiers in it. For the last 20 years, I just haven't had any gear failures , or any marking or pitting.
Straight cut gears do have a high shear load on oil, unlike helically cut gears.
Have the affected gears of ENGINR been hardness tested ? I would be super interested ! The stock gears look great though !!
I have a bit to do with PPG, and luckily they are only 10kms from my shop ! It is very interesting they stopped recommending Redline gear oil and wouldn't honour warranty if it is now used. They recommend the Motul full synthetic Technosynthese. I have to admit, of all the dog boxes I have serviced in the last 3 years, and all using Motul, the gear condition has been faultless....
Wow, I'm not sure what to do now. The PAR gearsets are cheapish compared to PPG, and I am assured by a 3rd party that the quality of these gearsets has improved immensely since production has recommenced in locally, rather than overseas ... Any one with any specific experience ??