I have a 2005 w/93,000 mi. It is my third and I generally consider the gen II one of the best cars ever made. I am running Touring 16" rims and tires and recently replaced the rear strut assemblies due to a broken spring. On the NJ Turnpike or similar, my car feel as if it is blowin' in the wind at 65 - 80 mph. This seems more noticeable when I am loaded, but not overly so and I am careful to balance my weight over the center point of the car and side to side. I have tried to look for wheel arch height specs several times as it sometimes appears that this and previous vehicles had sag in the back, but I have not found those specs. I have to hold the wheel harder than I would prefer and driving is not always relaxing. Any thought? I have not replaced front struts on any of the multiple Gen IIs that I have owned, maybe its time, but if I do I might look for a more complete suspension package. Are there parts from other Toyotas that should be considered? What experience have people had with ride height changes. I do enjoy snow and back road driving and I am not too thrilled about lowering my clearance anymore but I would consider it. Thank you!
Check it on an alignment rack. Stability problems as you are describing can come from a lot of things, but I've seen a number of similarly configured cars do the same: rear toe goes negative as suspension load increases. Now I've never checked a Prius for this, but if you find a good alignment tech they are going to find the problem anyway. Just offering that as a possible shortcut of things to check.
I bought a 1.5inch lift kit and plan to put them on rear end when I put new shocks and springs in to address rear end sag. Haven't installed it yet so can't say how it helped or hurt yet. But I look forward to roads trips that don't have that classic rear end sag that's much like one of the other greatest cars ever made in the late 60's: Ford Mustang.
Did you exchange the shock absorber as well while replacing the broken spring? Maybe the shock is at the end of its life and can't cope up with the new spring. I notice it a coilover system, did you replace it with a prefab assembly? Best regards, Nick Black 2007 Prius
Things that can cause "steering wander". Incorrect wheel alignment. Worn or damaged steering / suspension parts. Low tire pressure (or mis-matched tire sizes). Posted via the PriusChat mobile app.