Hi,

As far as I know the lower control arm bushings are symmetrical from side to side.
It’s only the ball joints that are not on the control arms.
The bolt pattern locates them with a slanted relationship to their bolt pattern.
If you place them side by side to each other, it visually stands out.
As I remember, when looking up at them on the car, they are slanted backwards to the rear of the car.

The knock “you might be hearing” can come from the rear most bushing when you roll over a slight dips in the road.
I need to ask, Does the sound appear to be “down low” by your feet of either side of the car?

This happens, if the stud and nut on the control arm, that goes through the bushing, becomes ever so slightly loose!
The stud pinches the bushings center spacer. It has to be held tight “within rubber” inside its steel shell too!
Just like the large rear axle trailing arm bushings except the bushing has a shoulder between the box holder and the moving arm itself.
The front arm is a little more dynamically involved with forces than the rear end while being locked under the cars frame.
Both bushings should not move laterally as this will allow the control arm to also shift but it still has to swing.
If and when enough force works the arm, it can thump radially inside the spacer too!
I think when we change out the strut cartridge the control arm gets moved way lower out of its normal working range of the rear bushing and it possibly rips the old rubber and crud a bit too!
In either case, that stud get looser somewhat than you would think!
It’s me guessing again, of course!

The cute thing about getting to that nut is that there is barely enough room to get a box end wrench over the end of the stud.
A regular length wrench will not get the nut tight enough unless you use a lengthening cheater bar. Even then, the swing is very limited to grab the flats!
In the past I couldn’t access that nut, with decent length wrenches, between the car and the ground.
So tightening it all up “setting it down on the ground” is not my favorite past time!
The whole idea of the rubber bushings being twisted up is twisted.
It’s just the way it’s made by the brilliants and I have to say that these fronts ends did fare better of holding their alignments than the domestic cars of this era!

Now, I have learned to drop the support box from the cars frame and remove the front bushings nut.
I Knock the front bolt back forward until it just clears one side of the frame that holds that front bushing.
I Do Not, remove the bolt completely, even though the upper mount holds everything up there, I don’t want any more to movement than necessary.
This allows the control arm to angle down, plenty enough, so you can “loosen or tighten” the nut on the rear bushing with sockets and extensions whether you are replacing any bushings or not.

No matter which way that goes for you, I like Arts method of cocking the box with a slight rotation of turn before tighten the nut back.
I use a socket and extension with a light zap of my impact. I then check the nut with a torque wrench to make sure it’s above their specification.
The specification for me is “ I want it Dam tight!” This is probably Above the 35 ft.lbs called for?
I push the whole lower arm up against the frame to get the bolts back into the support box.
This puts the bushing under a slight tension, called for in the Bentley, when you bolt the box back up onto the cars frame.
This works in reverse when the car is back on the ground.
The control arm goes upwards and relieves that tension to something close to a neutral twisted position.
This method works nicely since I have my car up on a car lift and use a tall screw jack to hold and push things back.

If the sound is coming more up front and higher under the hood, it is in the area of the strut towers!
This is a situation where the top nut cannot pull the cartridge rod shoulder up tight into the upper mounts bearing race.
I have “read” about this and the cure is to add a washer. It goes under the rods nut and on top of the bearing. The thread bottoms out in the nut.
An impact wrench “zaps” them apart and back together while the car is sitting on the ground so it’s a quick fix.

Not to be skeptical, but I have also read, on here, that some of those brand cartridges have quality, length or diameter issues within their model lines.
I will presume that since you buy from FPC that they sold you the right ones.

I surely respect all the posts made on this subject will help get the clunk out!

Phil