If you replace most of the elastomer (rubber) content with cheap filler, then it will look roughly the same when new & fall apart soon afterwards.Everything that is 2 1/2 years old (when it was all replaced) and rubber is simply falling apart. Hoses are cracking, seals are splitting and falling apart etc. How an earth are they churning out such junk?
The parts suppliers often blame us users, as we shop around for good value parts. Funnily enough I would happily pay for a good quality part (so would most people!) but have no way of knowing if that means paying over the odds for the same rubbish that's available more cheaply.
If there was a supplier that gave anything significantly more than the minimum legal 12 months warranty and stood by the quality of their parts 100%, I bet people would be beating their door down. as it's been heading this way for so long I wonder if any supplier could get high quality parts from any 3rd party manufacturer (as the entire supply chain has gone to pot / low cost economies etc.).
One example from me and now 10 years old - I gave up altogether trying to use 'standard' front suspension rubbers and switched to (much more expensive) poly bushes. The 'standard' rubbers were failing in a very short time and just weren't worth trying anymore.
Original suspension bushes lasted >>100k miles >20 years.
