Manufacturing process do have revision. Same part number diff revision. The revision can be for cost saving or parts improvement. I believe the defect only start to show lately , mitsu found out and did a massive recall base on part revision.
I believe the pulley will wear prematurely n cause it to start vibrate due to uneven and slowly snap the rubber belt.

It started recall few months back by mitsu. Now only proton got the orders from mitsu i believe. As th engies are preassemble from japan.

L.

Our v belt all in one!
Infact last time i claim compressor, proton have to bring a piece of paper and draw the v belt passage.. Lol..

Lifespan? I never bother.. Drive until patah only change.. hidup spirit of cheapskate!!! Else insurance give free towing every year not utilize