Knocking Sound When Spinning Front Rotors Back and Forth

[Uwe]

I would start with the obvious, eliminate the wheel hop, tires and the clicking tie rod. The 986 is very sensitive to alignment, so if you are thinking control arms, then do both sides and also replace the "tuning fork" arms. If the car had a suspension impact, then it might be wise to check the subframe, and also the shock towers. I recently replaced my suspension, brakes, bearings and struts, and found 2 of the 4 wheel bearings shot, even though they didn't wiggle during the usual tests. 2 of them were noisy with the brakes removed, and in the rear it couldn't be detected until the drive axle was out. I replaced all the wheel bearings, of course. I am amazed how well the car handles now, but I am equally impressed how well it still handled with the old suspension and questionable components. The vibrations in the steering are now gone, and the car feels like I imagine it would have when new. Keep on it and you will find the issue.

[Danimal]

Update, on just the right front: the clicking/looseness is the rack and not the inner tie rod ☹️. So I need to order a remanufactured one. The wheel bearing is tight and a little grindy (halfway done replacing it). The knock I was hearing from spinning the wheel back and forth is almost certainly the lower control arm ball joints. I’ll know for sure later today. Swaybar bushings looks okay, but replacing anyway

[Gilles]

Before you replace the steering rack, you may want to check the inner tie rod.

[Danimal]

Update: the right side is back together with the exception of the tie rods because I am waiting on the new rack. Before putting the calipers back on everything is tight and smooth. HOWEVER, as soon as I installed the calipers, the rattle is back when I spin the wheel back and worth. It sounds like maybe a piston is loose and rattling inside? Or possibly the pads sliding backs forth? Has anyone encountered something like that?

[997_986]

Originally Posted by Danimal

[...] HOWEVER, as soon as I installed the calipers, the rattle is back when I spin the wheel back and worth. It sounds like maybe a piston is loose and rattling inside? Or possibly the pads sliding backs forth? Has anyone encountered something like that?

Did you or are you able to check what I described in #10?

[Danimal]

Originally Posted by 997_986

Did you or are you able to check what I described in #10?

Not yet, I’ll have to pick up a dial gauge and some assembly paste.