Reply To: Bonded rubber bushes – unbonding?

The silentblocs were not part of the original design and were only introduced at a later date and, to the best of my understanding, their purpose is noise suppression.  Because the starter ring is exposed it makes more of a clatter than the 4 cyl. version and I guess the sort of people buying a 6 in its heyday were not pleased that their very expensive car sounded like a bag of nails every time it was started.

The silentblocs are mounted with the axis in a horizontal plane, front to rear and the load is from the side, effectively attempting to drive the outer metal element towards the inner part and thus squashing the polymer on one side and tensionning it on the other side.  I would expect little sheer force so the failures are difficult to understand.

Having experienced a second failure (only one item this time) in the last couple of weeks I have now fitted off-the-peg bushes from a UK supplier of such items instead of buying more, supposedly special, parts from a supplier of Traction parts.

I shall monitor their performance keenly and I have also taken the precaution of having some solid bushes turned up in case these also fail.  I shall be happy to revert to a solid assembly and tolerate the bag-of-nails syndrome for a few seconds when starting rather than worry whether the rubbers are still intact all the time I am driving.

Meanwhile, I too would like to know how long other owners have found these parts to last in their engines.

B……………