How do you know when you need shocks?
Bounce your car. Get it bouncing good and jump off. If it bounces more than three times before stopping, your shocks are shot. You could also have a buddy follow you while you drive down a rough road. If your buddy sees daylight under your tires, you need new shocks.
What if your rear end is low and you know that you need new shocksbut you also want to replace the coil springs?
if you go with original equipment you need to replace either shocks or springs or both with factory specifications. shocks are matched to springs by load capacity and rebound force, you see, if you swap out shocks for race shocks they will be a lot more stiff, you can play with shocks a little but the springs must match the shock specs. an example would be say,you replace your factory springs with racing-lowering springs, but…
Try a simple test. Push your car or vehicle with a substantial force downwards, towards the ground. Do this by pushing the hood down or the drunk down. If your car bounces fast and did it like a spring. You need new shocks or struts. This will affect your riding comfort. Some manufacturers specify to change the struts or shocks every 75,000 miles.
i recommend after 75000 miles. check for leaks around shock. rubbing, which causes bare metal to show. rust around shocks. do a bounce test: push a corner of vehicle down and then let up, does the vehicle oscillate(bounce) up and down more than once the vehicle is let go. if yes, change shocks. if the shocks are good, the vehicle will bounce once and level out.