I cannot get my Thrust Arm/Torque Strut ball joint to separate after 4+ hours of pressing & pounding with a hammer (2lb head). I started with the Gear Wrench separator (claw type) which popped all but these last 2 ball joints on my front suspension. This thing is so set in that it bent the fulcrum pin on the separator. I then went to Harbor Freight & got their version off the shelf. A couple more hours of working that tighter & banging with my hammer ended with a snapped off "beak" which was pressing on the ball joint bolt. I also tried pickle forks but there's not enough clearance to get a good, prying angle. Oh, I have also used an entire can of PB Blaster hoping that it would soak in & loosen things up.
I've tried the jack stand under the Control Arm as well as a floor jack pushing up on the torque strut as close to the joint as I could get it.
I've just ordered a brand new Gear Wrench separator so, I'll give it another shot with that in a couple of days. I'm trying to be hopeful.
Any tips & or tricks on what else I might try to pop this joint would be greatly appreciated.

 

Sounds like you're doing the right things.

Put the ball joint nut back on, tighten up, then loosen one turn. Drive the car down a bumpy road.

If that doesn't loosen it, drive down a good road and hit the brakes hard so the ABS kicks in.

Nick

 

Perhaps you could try the "two hammer" technique.

The principle is to put the heaviest steel weight that you can get to sit against one side of the stud socket, and then hit directly opposite that with the heaviest hammer that you can swing. The impact elastically (temporarily) distorts the tapered hole in the socket area, causing the release of the tapered stud. There is no damage to the taper.

Obviously, there are often serious access issues.

You must also be very careful to avoid personal injury. The metal on the back of the socket (the anvil) will bounce off of the socket area with considerable force. You cannot hold it hard enough to prevent that, and it is all to easy to have the hand holding the anvil slammed into a nearby solid object, with painful results. That is one reason that mechanics use a large hammer as the anvil, as holding the handle helps avoid such pain. Another common anvil is a large steel bar - say, 2" in diameter and 6" long.

You also must be very careful to avoid damaging nearby objects with the striking hammer - things like sensors, wire harnesses, brake lines, etc.

With all of these potential problems and drawbacks, the two-hammer method does work...

 

Just keep trying it will come off. I used the same harborfreight balljoint separator. I had to buy a couple of them before it eventually worked. I had to use the hammer with it hittinng from the bottom while slowly tightening more and more.

 

have you got it separated?


by the way this idea enlightened me;

 

I graduated to a 3 lb. hammer, with a shorter handle, & got it to separate in 8 hits. I didn't even need to take the new Gear Wrench separator out of the package for either side.

This is the 2nd W220, front suspension from which I've replaced all of the arms and ball joints. The 1st time, on my car, I pulled all them all from the frame so they were still connected to the steering knuckle. It was so much easier than this time where the guy I'm helping out wanted to do them with the steering knuckle attached.
Pulling everything took under 5 hours for both sides. It took just under 20 hours when leaving the steering knuckle attached. Without breaking tools & the horrible clearance, it was maybe 17 hours at best.

 

Ahh! 20 hours?? I'm about to do this on my '05 S55 + the rotors and pads. I don't have 20 hours... Sounds like I need a couple of those ball joint separator kits.

 

For upper & lower control arms, lower ball joints, thrust arms & outer tie rods it took 20 hours but I forgot to mention we certainly didn't do them all in 1 day. That's getting the car onto stands & pulling the wheels 12 times including 4 extra times because I couldn't get the 1 ball joint to pop loose. If everything went well, with the car going up on stands once & leaving the steering knuckle on the car the whole time, I still can't see it being done in better than 12 hours.
Especially since you're replacing the rotors, I can't see why you wouldn't pull the steering knuckle & get everything put together on a work bench rather than sitting under your car.
There are 4 ball joints that connect to the steering knuckle. You'll definitely want to have a separator on hand. You'll also need a ball joint press for the ball joints in the lower control arms. Make sure you have 21mm wrenches & sockets plus E-torx sockets. Those are the female torx sockets which you'll need to release the external torx screw from the strut at the control arm. I can't remember the size but they come in a set of 5 or 6 & it's one that's in the middle so you'll be good with the set. You might want a small butane torch or heat gun/hair dryer if you have a tough time getting those screws to break loose. I can't think of anything more oddball that I needed beyond a regular tool kit.

Below are the torque specs for reconnecting the arms. I found them on another forum & had to refer to them often.

Base w220 not 4matic Torque specs front end

A - Front stabilizer link rod to spring control arm 150Nm
B - Front stabilizer link to stabilizer bar 150Nm
C - Strut to spring control arm 20Nm
D - Spring control arm to axle carrier 80Nm then 120 degrees
E - Spring control arm to steering knuckle 50Nm then 60 degrees
F - Radius rod to steering knuckle 50Nm then 60 degrees
G - Radius rod to front axle carrier 80Nm then 120 degrees
H - Tie rod end to steering knuckle 50Nm then 60 degrees
I - Upper control arm to front end 50Nm
J - Upper control arm to steering knuckle 20Nm then 90 degrees

 

Thanks for sharing your experience.
Just changed all three arms myself (2 lower plus upper). From my experience, it is far easier for a diy (esp without a hoist) to remove the knuckle, even just to change the lower ball joint.

Did you have any problems with front end airmatic after the job?

 

I haven't had any Airmatic issues after changing out all of the arms.
I did, however, have an issue while changing an upper control arm. The bracket that holds the level sensor is mounted between where the control arm connects to the frame towards the front of the car. There's a groove that the bracket should fit into but you have to make sure the bracket doesn't move out of that groove when you're tightening down that bolt. If it does, it will make your level sensor off & your car will be lower (mine bottomed out) on that side. You'll have to back track & get that bracket back into the groove where it's supposed to be.

 

Thanks for the reply, appreciate it.
Yes, I would like to ensure I re-installed the sensor properly.
However, I am not quite sure what you mean by the 'groove' that the bracket fits into. Do you mean the square hole on the bracket that the tab on the sensor fits into (see picture attached)?

Or some other groove? If so, is it possible to explain a bit more where this groove is situated???


Thanks so much!

 

The groove I was referring to is the indent in the bracket around the control arm to frame bolt. When working to get the bolt in & started to tighten, the bracket can flop around a bit & become misaligned so I suggest double checking that the tab is still in the hole & the bracket is aligned before torquing the bolt down completely. It's such a tight fit in there, it's a real pain to have to go back in.

 

Thanks for the reply.
The tab is definitely in the square hole. And I also understand that the bracket assembly does flop around quite a bit and it is a tight fit and hard to visually check the alignment. I believe it is in correctly but I will check it out again.

Thanks again for your tips.