[Whiterabbitt]

My money is on the strut bar. Easy to test, disconnect the endlinks and go for a drive. I’m pretty confident this is your issue. If you have an H&R bar back there by chance I am 100% confident that is your issue.

the other way to test is to get under the car and hit the bushings with WD40 and go driving. That should make the squeak vanish too if that’s your root cause. But careful, this is actually a terrible idea because it’s short lived and there is a high risk of “causing” a bushing squeak if that wasn’t your root cause, and if it was, the squeak will come back in a couple days anyways.

If this is your issue, the fix is:
1. Take the bushings out, clean the junk off them, clean the bar, make it spotless and dry, reassemble.
2. if that doesn’t work, get some well respected bushing grease and reclean, apply grease, reassemble, and clean the exterior.
3. If that doesn’t work, buy replacement bushings and do #1 and #2 in order again.
4. If that doesn’t work, buy a new bar (H&R) and repeat 1 and 2.

Anyway, easy enough to test. Yes I have experienced this squeak.

 

[Whiterabbitt]

I get to them from under. Either on ramps or jacks. Yes both sides disconnect.

If you hosed the underside with any solvent, I'm more sure than ever it's your bushing. I totally get where you are coming from about no-way-capillary-action, but I don't agree. Not gonna fight about it or anything, I just strongly believe spraying is enough to get penetration in there.... and the subsequent squeak.

So I'm more sure now than ever that the bush is your root cause, and the solution is to unbolt it, clean the heck out of it, and put it back dry.

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For the record, I have some really nice sway bar grease (snake oil?) in my toolbox, but I never got to the point of using it. What worked for me was clean, clean, clean, and put back dry, dry, dry. I'm not sure if using purpose specific grease is a good idea or not.

I can tell you for darn sure WD40 makes it worse. When I had my squeak from crap getting in there, I hosed it with WD40 for troubleshooting pathfinding, and the squeak went completely away. I knew what was coming tho, 2 days later and it was worse than ever. That's what triggered my 1-2-3 plan above. But I never got past #1 because it worked.

Lasted 1-2 years no squeak, so I'm a few months away from being due again if the crap-accumulation is happening at the same pace.