I have noticed that the rear coils have become very soft over the last three years or so on my 02 2.4 V70. The front struts have been replaced but my mechanic swears the rear end is fine on my car. With less than 200 pounds of cargo in the back the car is close to being bottomed out. When I carry a mountain bike on my hitch mount rack the the trailer hitch grinds the road as I pull out of a parking lot or my drive way. I am considering using the rubber coils spring stiffeners to maintain more ride height when I'm carrying a load etc. There are options that will keep the car 1 or 2" higher when loaded down. Has anyone else tried these? I know prolonged use is supposed to be bad for the springs.

 

On one UK Volvo site I have seen an analysis of the use of these spacers to raise body of the car with weakened springs. In a series of posts from an apparently knowlegeable person these spacers were not considered a good solution to weak springs.

The auxiliary coil springs that fit around the shock were seen as the only durable and safe solution. See Grayston Engineering Spring Assisters

 

I am using these on the front Superior Automotive/Coil Spring Booster 18-1901 at AutoZone.com and these on the rear Superior Automotive/Coil Spring Booster 18-1601 at AutoZone.com - 1 reviews


I have no issues with them. I tie straped them to the coils so they don't move once it was back on the and the spacers were under pressure. Made my 2002 XC70 feel much better. I am very happy with the $20 upgrade.

 

It is misleading to call these rings "boosters". They should be called "reducers" or "supporters". What they do is make the spring stiffer by removing one coil from moving in response to suspension forces. They transfer the stress from the supported coil to the remaining unsupported ones. If the vehicle is never heavily loaded, then it may not shorten the life of the spring so under those circumstances it could be said to be an effective intervention. Of course the inevitable wheel on a bump or into a pothole will then shake the body more than if the standard setup were in place.