Bought the parts now so I'm committed. I'll let you know once they're all fitted whether it makes a worthwhile difference, or whether I've just spent hundreds without really needing to...
Sachs shocks + Meyle HD droplinks from PartsForVolvos. The rest of it will be Volvo bits which the garage will source (not going to be fitting myself).
One of the rear shocks had this line of wet on it straight out-of-the-box:
I wiped it off and it seemed to be colourless. The others don't have any of that, maybe just some very light moisture, are those photos cause for concern? Performance of the pair does seem to be the same.
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I was curious to find the fronts are significantly softer to compress than the rear... that's interesting to me, I'd have thought the fronts would be stiffer as that's where most of the weight is? Would be interested to hear the theory to explain this...