Good day all,
I am a new member to the club - although I have found many useful advice here as a non-member before - and wanted to share my recent prop shaft failure to learn whether anyone else had experienced this before?
My 2007 Pajero IV GLX (289 000km) prop shaft failed catastrophically, without any warning, luckily at low speed whist pulling away on an incline!
My mechanic refurbished the universal joints on either end two weeks before and when confronted on the failure he claimed 'carbon fatigue' prevalent on high mileage vehicles (as apparently confirmed by Mitsubishi SA Technical and Japan)!?
I was not convinced and engaged a composite material expert on the matter, who explained; "While it is possible that the shaft simply failed in fatigue, this is extremely unlikely. As a well-designed composite structure (from a reputable manufacturer like Mitsubishi), as this one visibly is, has multiple fiber orientations which makes it almost immune to fatigue. Such carbon fiber components are however, extremely sensitive to damage caused by transverse impact (something that could easily happen on an exposed drive shaft). This causes delamination of the different layers, and the cracks between the layers (or plies) can then propagate through fatigue. Eventually, when the delamination’s are big enough, the plies can move relative to each other and you lose structural integrity – ie, the shaft fails. The failure would almost certainly have been caused by some sort of impact in the past, which resulted in delamination which subsequently progressed until failure occurred."
Or the shorter version; fatigue failure would almost certainly have propagated from some sort of damage.
Such damage could easily have stemmed from a bump or ding whilst driving (a few such incidents whilst 4x4-ing on rugged terrain is mentioned on other forums), OR in the workshop (typically when over clamping the prop shaft in a bench vice)?
Please comment and share your experiences.
Regards,
Matthiam Hoffman
