I lowered my 07' C70 1", and 5 axles later.....
 

Hello, I recently bought a C70 w/58K miles. Before replacing the springs, I called the manufacturer (Eibach) who assured me the struts and axles would be fine if I installed new springs
to lower the car 1". One lousy inch! After installing the springs, there was a slight, but still noticeable vibration in the steering wheel, only btwn 12 and 16 mph. Before getting the chance to have it checked, I was out of town, and when making an easy left turn, the left axle broke away from the wheel and landed in the street. I had the axle replaced, but the vibration persisted. Upon arriving home, my trusted Volvo mechanic deemed the replacement axle defective and replaced it. The vibration persisted. I took it back in and he replaced it for a third time. (what are the chances?) Still vibrates, only at a different lower speed now. He then replaced the right axle, which made no difference and again replaced the left axle a 4th time. It still didn't help. I have had the tire balance and the alignment checked. They are fine. I am told the wheel bearings and control arms are fine. My mechanic (who is doing a TON of this work 'pro-bono') thinks it HAS to be the springs. I have seen other Volvos *much* lower than mine, so I find it hard to believe this vibration is happening because of the axle(s). My questions are these:
1) If indeed the springs are causing too much tension in the otherwise flexible axles, are there after market axles that will handle the extra tension and not have the vibration problem?
2) Was my C70 meant to not be lowered and is it destined to look like every other C70 on the road? :-(
3) Has anybody else here experienced this (or anything similar) themselves?
Sorry this is so long. ~John

I had to do the axles on my 09 at under 45k from torn boot. It is a common issues unfortunately.

As far as lowering it, you are changing the working angle of the parts, so that could be affecting it. Something could be rubbing now that wasn't also. If you put the original springs back in, does the issue go away? If yes, then it is related to them. If no, then there is something else that is causing the issue.

My cars are all stock, so I can't help with upgraded part recommendations.

One thing I will say, is check to make sure your car was aligned to the right specs. My 09 had to go back because they initially aligned it to the V70 specs, rather than the C70 specs.

Thanks for your reply. I forgot to mention that I have had my (nearly new) 18" tires and wheels checked to make sure they are balanced, as well as having another 4 wheel
alignment. Unfortunately, the problem went away after the original springs were put back on the front. I am saddened that I might not be able to lower it that one inch. It kind
of makes me wish it were a rear-wheel drive car because I would probably not be having this problem.

Additionally, does anybody know if re-installing the lowering springs (and living with the small vibration they make) will cause undo stress on the axles? I don't drive
the car much (mostly on the highway) and since the vibration is at lower speeds, I'm wondering if I can get away with doing that. I really love the way that danged
car looks 1" lower. (blargh)

When you say you fitted Eibach lowering springs did you also replace the shocks? I lowered my C70 T5 convertible 40mm with custom springs and shocks some two tears ago and I also have 18" wheels and I have not experienced any problems. I would check the shocks first, maybe change the fronts for a couple of Bilsteins.