Scratch that. I Reread your original post and it can't that. I'm thinking about the way you are testing it (on Jack stands) do it again, but this time make sure the jacks are on all 4 lower control arms, so the suspension is loaded. Hope this helps

 

I put the spare tire on the front drivers side in order to determine if the caliper interference was a major contributor. Conclusion: it is not.

At this point the noise appears to be coming from underneath the drivers feet in the front. There are no indications of anything striking something associated with the drivers side front CV halfshaft. Thus if it is associated with this halfshaft it is either inside the rubber boots of the halfshaft or is inside that side of the transaxle.

The knocking is in sync with wheel rotation, once per revolution. It came on about 400-500 miles after the initial CV Halfshaft replacement. On the second replacement it began almost immediately as it did after the third replacement.

It only occurs with load on the wheel bearings. I've replaced the drivers front wheel bearing. I've had the car up on jackstands, all four corners, and run the engine and powertrain. No knocking.

It starts up about 3-5 miles after moving, as if something needs to warm up a bit.

It goes away with steering turn either direction. It goes away on hard acceleration or coasting.

I'm going to put it back up on jackstands and inspect the Pax front wheel, the halfxhaft, and the intermediate shaft. Also as noted the PTO unit and the carrier bearing. I'll look at the rear wheels but the noise seems to be clearly from the front somewhere.

If I have it right the inner CV joint if failing should be 3X rotation and the outer CV joint 6X rotation. The PTO would be some kind of grinding not knocking. The carrier bearing midway along the propeller shaft to the rear axle would be ~2.73X the wheel rotation.

Any thoughts out there?

 

Car up on jackstands, changed transaxle oil, ran engine for 20 minute w/u. Then listened to various places with automotive stethoscope. Only noise of interest was the intermediate shaft bearing which wasn't smooth but sort of "rocky." More to follow on using the stethoscope.

 

You may have to provide a load by using a 2x4 against the wheel(s). Jamming one side would force the other side to spin alone. Pulling the proper fuse would kill the rear wheels also.

 

Put this up on the 100,000 mile entry also.

Well... It's in the strut (drvrs side).

I split for a Steelman Wireless ChassisEAR unit. Got it from Tooltopia, good price w/free shipping. Got it within three days from order to delivery. Good customer service.

Put sensors on the brake caliper, transaxle, lower arm, and at the strut midpoint where the sway bar link attaches. No noise from the caliper to speak of, a nice rotational hum-m-m from the transaxle that varied with speed & gas pedal input (ie MG2 is connected to the axle but MG1 spins at different rates).

The lower arm showed some of the cyclic knocking. The strut midpoint sensor very clearly had the knocking. This was located on the attach point for the sway bar link.

Will put the sensors more specifically on the strut to see if I can pin in on where the noise is coming from.

Anybody out there got any experience here? The knocking I have is same as the wheel rotation (eg 1X wheel rotation), disappears on coast & hard acceleration and with steering input in either direction.

What I don't get is the synchronism with wheel rotation. I see no indication of the wheel or strut itself contacting anything and I've swapped wheels side to side with no change. On inspecting the upper mount inside the engine compartment all seems tight (I use thread locker).

 

Just posted this on the discussion for 100,000 mile report:

An extended run (80 miles+) last night.

There were two problems kicking my behind across this drill.

First was the failed MacPherson Strut on the drivers side. Because I didn't believe that it could fail I easter-egged with other things: wheel bearing, sway bar link, lower arm, sway bar bushings. Each item individually was less expensive than a replacement strut, yet clearly I'd have gotten off cheaper if I had (1) bought the ChassisEar sooner and (2) listened to what it was telling me shortly after I got it.

In the end the ChassisEar system told me the truth in the middle of my trouble shooting and I didn't believe it for awhile. The noise on the strut midpoint mounting for the sway bar link was the give-away. That was always noisy and everything else was not as loud. Once I replaced the strut this noise disappeared. It just vanished.

Still I had a knocking, albeit somewhat different and only in a small left turn, but there. I suspect the new strut changed the geometry somewhat and allowed another problem to surface producing a somewhat similar sound on the pax side.

I've had a longstanding issue of front caliper interference with the OEM wheels since I first replaced brake pads and later installed rebuilt calipers. I had ground down the calipers a bit to clear this but it somehow didn't go away.

So in this drill I spent a considerable amount of time on this with a Dremel Moto-tool to eliminate any interference from the caliper. That paid off as last night there was no audible noise on my trip of 80+ miles. There was some noise to be heard on the ChassisEar, so I suppose some more time with the Moto-Tool is in order...

But in the end what fixed things was the strut replacement then getting down to business on the caliper interference thing.

Having to work through two similar symptoms could not have been done without the ChassisEar. That was a good investment.

Note that I did look into the Ford Tech Note on subframe pins & alignment but the symptoms didn't really match.

Second Note: RockAuto did not hesitate to make good on the Monroe Lifetime warranty for this strut. They're some of the good guys along with my local NAPA folks.

Buried in this caliper issue had to do with the grease being used on the caliper guide pins. It appears that the regenerative braking heats up calipers far more than I have ever seen on any other car. So I obtained some really high temperature caliper grease.

The previous grease would burn up & coke on the guide pins causing the calipers to mis-align. So when you rebuild calipers or change brake pads use a really high temp grease on the guide pins such as:
Permatex "Ceramic Extreme Brake Parts Lubricant" (Item #24125).

This caliper lube may seem to be overkill as its rated to 3000ºF, but it's not that expensive (an 8 oz bottle was maybe $15...) and that one bottle amounts to a lifetime supply for me.