Volvo Repair: Installed New Struts And The Spring Seats Got Busted, fcp groton, strut mounts

Question
 I got new spring seats and Sachs OEM struts from FCP groton for my S70,did everything right...compressed the springs to 11.85 ,put everyting back,after 2 moths a terrible ratling noise appeared.I only replaced one spring seat,the other one looked OK.I didn t drive the car for a while,today I took the struts apart and both sping seats have the inner metal ring pushed through upwards.What did I do wrong?Did I under or overtighten the top nuts?Is it because I didn t change the strut mounts as well?Thanks a lot

Answer
Those spring seats just have a tendency of coming apart. Usually the rubber cracks apart though.  I would get the seats directly from the dealer.  They are just as cheap 20-30 each and you should get alot more miles out of them.  Yours just broke, there is nothing with the install that would have cause them to break sooner rather than later.  The strut mounts themselves don't ever need to be changed unless the bearing is going out or the plate is bent.

James