05 STS front end clunk

[kevm14]

I worked on the car in my mind while in bed last night.

What I came up with is that there is probably a heat shield behind the rotor that I bent and is rubbing on the rotor. I jacked up the driver's side by the ball joint and the stud dug into the wood possibly enough for the wood to contact the bottom of the rotor. It may have bent that into the rotor somehow. So I have a hypothesis. I may also knock off the rust on the outer edge of the rotors with a wire wheel on a drill for good measure.

I was correct. There is a very small heat shield that protects the lower ball joint from the direct heat of the rotor. It only covers the area of the rotor covered by the knuckle. But sure enough it was definitely touching the rotor. Here is the noise:
https://youtu.be/FVTQ06Ik4Ss

I simply bent it away and also got out a chisel and wire wheel and knocked off all the loose rust on the rotor, on the parts where the pad doesn't contact. I also did this to the passenger side though I don't think it was rubbing. Seemed like a good idea though while I was at it and the car was in the air.

Pro tip: turn off traction control when running the wheels of an AWD car, when only one end is raised. Otherwise the traction control may try to launch the car off the jack stands, by braking the front wheels which are "slipping" and sending power to the rear.

Other fun facts: AWD with open diffs and an open transfer case is really just 1 wheel drive unless traction control intervenes. I proved this because the rear was on the ground, and I was able to stop one of the front wheels from turning, leaving just the driver's side front wheel turning. The speed would have been 4x speedo indicated because of the doubling factor of the transfer case AND front diff. Kind of interesting.

But yeah, I road tested it and it's totally fixed!!

This car drives pretty damn good aside from the still failed engine mounts. It feels considerably better over uneven road than before. Also, this platform feels much more athletic than the E55. The steering is more direct and a better ratio. The suspension is frankly more sophisticated because I think MR shocks and coil springs are superior to air springs plus adjustable shocks. It turns in sharper, the chassis feels stiffer, it's just much better for cornering. Definitely slower but the trans works much more transparently which I also appreciate. I enjoyed driving it again.

Now I can order 2 front tires and get an alignment. I am going to switch the fronts to 255 to match the rears, so I can rotate in the future. Stock is 235/50. The rear is already a 255/45 and I'll just switch to that on the front, which was actually an available package. I will also ask them to rotate the rears to the front and put the new tires on the rear. Hopefully they can handle this and not get totally confused with the 235s (and replace the wrong tires or something).

Again the alignment actually feels decent but I'm sure it needs to be adjusted. Hopefully if it actually needs caster/camber, they will take the time to do that. I'll see if I can go over all of this with them or ideally, the tech.

[kevm14]

Got my new tires and alignment. Replaced the front 235s with new 255s (matching the Continental ExtremeContact DWS06 I had on the back), and had them rotate those to the rear. Not sure if they reset the TPMS but I'll find out at some point if it's right since I'm sure they'll leak.

20201031_110533.jpg

Looks like I actually installed the new stuff in a perfectly green position. The tech did nothing but toe on the front end.
On the rear, he marked that the left rear is out of adjustment but I don't think that's true. Looks like he just did toe back there, too.

Drives about the same as before, maybe smoother.

I was able to remote start it to clear it off before my appt this morning because I had reset the CEL earlier this week. On my way to Tire Pros, it came back on. I reset again in the parking lot.

I do actually feel and maybe hear some occasional noises from the front, STILL. However, the ride over bumps is 100% improved and I am certain all of the work was worth doing. I don't hear any clunking or rattling going over bumps. Not really sure what could be making occasional noises unless it is that damn end link that I had previously struggled with. Probably not going to do anything other than drive the car. Everything has been replaced now. Could it be the engine moving on the bad mounts?? I have no idea. Again, it should be perfectly safe so not going to worry about it.

[kevm14]

So there's still something going on. I am worried that a lower ball joint is loose in the knuckle. I better check that. Otherwise I'm struggling with what this is. I guess it could still be the anti-roll bar end link thing but when it clunks I feel it in the floor. I'm not sure I'd feel that so much as hear it. Sometimes it clunks frequently enough that it's like I didn't do any suspension work. Sometimes it doesn't clunk much at all. It's very strange. Won't do it over a speed bump or many road bumps. But certain conditions trigger it and usually it's not a bump at all but more like a gentle hump while turning left or something.

Maybe I torqued the lower ball joint nut improperly. It requires a pre torque and then a degree. I think I did the degree with a breaker bar and socket. What if the ball joint spun instead of tightening the nut? That would be bad. Could have even ruined the knuckle (which is aluminum). I better check that ASAP.

[kevm14]

Mixed bag.

Drove it onto ramps. First thing I did was check the driver's side lower ball joint nut. I was able to loosen it without turning it very far which did not seem correct. I tightened it with one wrench and then doubled them up. I think I must have ended up adding at least 180 degrees (half a turn) to that nut. I do not think it was tight enough.

I also checked the passenger side. Kind of the same deal but a little different. It, too, loosened up without much of a fight. It also seemed to get tight with fewer turns. I felt like the clunk originated from the driver's side so that seemed to make sense.

I did nothing else.

Road test revealed, like I said, a mixed bag. I don't know if it's a placebo but it felt better. However, I think the issue is still present. It will do it sometimes upon medium braking as you slow down. Like when you apply the brakes at a medium firmness at like 30 mph. I also ran over some pot holes and thought I felt that harshness again. Some of the same harshness that made me think my lower control arm bushings were shot. I'm not sure they were totally shot though it's still good to have freshened that stuff up.

I do definitely get a clunk upon acceleration if the suspension is moving up and down. As far as I can tell this is engine mount related. I don't know if the front diff is also isolated some other way and maybe that's part of the issue. I'm actually not sure how it attaches to the car. I should look that up.

So yeah....while it does seem better (or it's a placebo - plus I am 99% sure those nuts were not tight enough), remaining ideas include:
- Anti-roll bar related. I could try jacking up the bar and see if I can get a clunk out of it as it slips on the end link. I've been talking about this for years and based on what I have done, the only thing that would fix that would be a new entire bar because the hole has become elongated (I believe it was loose and clunking when I bought the car). Pretty sure I'm not doing that. This is also not a safety issue. Also, I do not think this would cause the harshness I feel but maybe the clunk in the floor.....could be two things I guess.
- Engine mount related. Moving around and clunking is not outside of normal for worn out mounts. I can't seem to isolate the issue to just mounts as I can't really replicate the harshness I feel just stabbing the gas. But maybe over bumps compounds it and something is smacking the subframe....

I think I need to try my anti-roll bar experiment next time I feel like getting under the car (which is never, especially in the winter). The other option I have is to actually disconnect one of the end links (any of them) thereby decoupling the bar and drive around with no front bar for a while. Not a huge fan of this idea but it is still an option.

I do feel better having tightened the lower ball joint nuts but it's frustrating that it didn't seem to fix the issue. And for what it's worth I watched the studs the whole time and never saw them turn as I was tightening the nuts.