1993 850 was the only year that Volvo sold control arm bushings. Probably due to dealer complaints that the process took too long and was error prone. Ever since, the DIY community had no choice but to buy complete control arms and then there was always the quality control issues of after market junk. I don't think you can find bushings even if you have a 12ton press.

Same is true for CV axles. Most OE axles are good, just the boots crack. But it is faster to change the entire axle than replace both boots. With labor at $100/hr...
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Keeping it running is better than buying new