Rear End Really High Up? Spinning Out, '07 LS Coupe
I was wondering if someone could help with this problem. My '07 LS coupe (FE1) at 86,000 miles is a great car body and drivetrain-wise (very low rust, reliable start, getrag 5-speed), easy to work on, but the past few years I've had some very serious wobbling at highway speeds.
In troubleshooting I've found what I believe were compromised parts that could've resulted in catastrophic failure, but I've still got the wobble. I live in the salt belt and some of these items failed due to rust. Some of the items I've replaced in the past three years are:
- shocks and struts with KYB's at ~50,000 miles (~4 years ago). The rear stock shocks were dripping oil from salt-belt rust holes
- rotors and pads ~3 years ago due to warping. No problems since.
Last year I went nuts replacing parts, and it helped the car a lot with other problems, including :
- entire rack & pinion & all tie rods (was clunking when moving the tire by hand at 9 & 3 o'clock...new parts eliminated the clunk)
- front lower control arm, moog problem solvers (fixed the low-speed bushing clunk)
- KYB upper strut mounts (one OEM mount had torn completely off the rubber, the other looked ready to fail).
- FOUR new tires professionally installed and balanced (old tires were almost 8 years old). New ones are a Michelin brand I think
- stabilizer links
- calipers and hydraulic hoses (was bleeding brakes and the bleeder on both OEM calipers broke flush with the caliper)
- greased and torqued everything (moog stuff has zerks)
- two alignments
This year I replaced the intermediate steering shaft (u-joint had rusted and seized; the car wanted to keep turning after making turns) and also the front bearing and hub assemblies.
After all this I've still got extremely bad high-speed wobble. The car occasionally feels like it's a boat, floating on water sideways and ready to flip sideways especially in strong winds. I can barely get up to 55mph meaning EVERYTHING passes me on the highway.
However, the wobbling has gotten worse. Last November I spun out going up a steep hill / blind-curve in the rain; the rear end wanted to keep going straight, so the back-end of the car swung around and I couldn't believe the car was spinning out. I was only going 25-30mph up the hill. Luckily I only ended up in a ditch and got pulled out.
Looking at the car the rear end seems very high. I did the "bounce test" and it bounces twice. I also put about 400 lbs of items in the back seat and the rear end lowered dramatically. The bounce test on the front barely moves, no bouncing at all.
These KYB excel-G rear shocks barely have 30,000 miles on them and they look like they're covered in oil and road dirt. Has anyone else had KYB's fail on them this quickly? Anyone have success with submitting a claim for the lifetime warranty?