ack5252

What is the proper procedure for pre-loading when installing new springs?

sillyboybmxer

turn the locking collars till the spring doesnt move freely, then snug them up a turn or two

macr88

Preload amount depends on spring rate and stroke length.

RedCelica

What if there aren't locking collars

sillyboybmxer

Good point.

RedCelica

TMK, the procedure requires you to set the coilover (spring,strut,top hat assembly) in place with everything hand tight and all nuts and bolts in place; jack the lower control arm up until the car comes off the jack stand, then tighten everything to spec. Please someone correct me if I'm wrong...I'll try to find the thread that I read that from.

macr88

^ that's bushing preload and I jack up to ride height then tighten, if you're running softish springs your method might be way past ride height.

Spring preload is different and has more to do with available bump, droop and where the piston runs in the damper.

macr88

Also just for info, we have shocks or dampers not struts. A strut is a specific type of damper.

ack5252

Thanks for the input guys, RedCelica the way you described it is what I thought it was but wasnt sure about which particular bolts to leave loose until its been preloaded. Do you mean ALL of the suspension bolts (e.g. control arm bolts to car bolts, the bolt that connects the damper to the lower arm, the bolts that connect the control arms to the knuckle, etc.). Also, I am running Swift Spec-R Sport springs. Spring Rates: Front: 7.5 kg/mm Rear: 7.0 kg/mm.

RedCelica

I am referring to all the bolts that make direct contact with the coilover assembly (so no, not the control arm bolts). Maybe Mac could shed some knowledge on the subject.

The spec-rs are pretty stiff for a lowering spring. Once the car is on the ground, I'll recheck all the torque specs at least up top. This is my method, but it may not be the best way to do it...haven't had a car fall apart on me yet though