OK,
The car went to the Volvo dealer ( while under warranty ) because the tailgate handle was sticking,
and the tailgate could not be opened easily.
Dealer "cleaned and lubricated" the assembly and returned it to me "working"
stating that the part had not failed so Volvo would not replace it.
I disputed this on the grounds that that the part had a material defect -
namely the manufacturing process used to prevent corrosion ( zinc passivation ) had failed
during the warranty period, and argued that the part should be replaced under warranty.
After sending a photograph ( attached ) to Volvo Customers of the visible part of the tailgate handle pivot pin,
AFTER it had been "cleaned and lubricated" by the dealer, Volvo Customer services have agreed to replace it without charge,
although "without prejudice" and the caveat that this is a gesture of goodwill.
They do not admit that the part actually needs changing !
So it looks like I have another 2 - 3 years before I need to do the stainless steel rod modification myself :-)
