First: wife provided fresh fruit smoothies for hot day work. Just like St.Maarten, but without the beach part, lol.
Today decided to take some of the rear end apart to try to figure out why I'm still getting the occasional hard BANG from the rear underside of the car. It's like someone is smacking the bottom of the trunk or backseat or something with a hammer. Only happens when the suspension unloads and the reloads and I get on the gas hard in a certain manner. And only while turning right.
This has annoyed me since everything back there is rebuilt or new pretty much.
First addressed the usual suspects:
driveshaft center support, giubo, and u-joint - all appeared and felt fine
suspension bolts in the rear - all torqued to spec still
rear subframe bolts - torqued to spec still
diff bolts - all of them had loosened up a bit, but not enough to allow movement.
re-torqued them all with some loctite
axle bolts, etc - all torqued to spec still.
exhaust - still tight, hanging nicely, and not banging on anything, even when pushed as hard as I could with my foot.
checked the calipers and they were fine. no evidence of pad knockback or anything (not that I'd expect it with sliders anyhow).
down to 2 possibilities: First, the parking/ebrake. When the car is moving, the first time you pull the ebrake (and no, I don't do it often), there is a loud BANG that I haven't quite figured out what it's from. Sounds like its coming from the cable itself back under the car, but the cables are new and they seem to operate fine. And it's only the right-side cable that does this. So maybe the cable is binding when the suspension unloads or something and causing the same noise.
Took the rotors off and checked the ebrakes and cables, but everything appears to be in good shape and adjusted correctly.
Last thing was the rear springs. When I swapped to the "S" springs I took out the rubber spring isolators on the top and bottom to drop the car in the rear and extra 3/8". When unloaded the springs are now able to move around a bit if pulled by hand. Maybe they're binding on the LCA or something and causing the noise (doubtful, I think). But since i'm under there doing stuff, I went and put the isolators back on.
Long story short I drove the car and couldn't replicate the sound now. That doesn't mean much since the sound happened very occasionally and usually only on-course, but we'll see.
pics, as usual. Nothing too exciting though.
overview. Not too too dirty since I sprayed off the underside last week
this is my rear (extra) exhaust hangar after 2 months. what garbage....ugh.
spring pad-less. you can see there is some "play" in the centerbore on the nub
my neighbor also came over and asked me if I wanted a foot locker/travel container thing. Without seeing it, the answer was of course yes. After removing his daughter's stickers from it (such as "we love you Allie!"), decided to test it out in the car. As luck would have it, this box fits perfectly WITH my current gearbox in the e30 trunk (and with a small cooler, small toolkit, and 2 folding chairs).
So now I'll have one gearbox specifically for tools, fluids, and repair stuff and can use the other one specifically for all the rallycross gear (helmets, spare clothes, bug spray, shoes, towels, etc). Excellent.
Does take up the space I needed for my big pop-up tent shelter, but that can fit in the backseat with the wheels/tires anyhow.
new gear box
old box alone
both boxes, cooler, tool kit, 2 chairs, full-size spare, and some other crap. Damn I love the e30 trunk!!!!!