[Sergio]

A couple of weeks ago, I took my '02 ML500 to the dealer for state inspection. I've had a close relationship with this dealer for over 10 years and trust their findings. So, I was told my truck needed the following items:
1) Motor mounts
2)Tie rod ends
they suggested I replace the following:
3)Shifter bushings
4)Ball joints

so, I took care of items 1), 2) and 3). One of the motor mounts was cracked (you could separate the two pieces with your hand. One of the tie rods had been leaking grease and was completely shot. The other, had a bit of play.
The shifter bushing was gone so I replaced it with a new one.
So here comes the problem:
I tried to replace the ball joints but could not remove the brake rotor or the upper ball joint (mounts to the upper control). I removed the 35mm axle nut and the rotor would still not slide off. I obviously removed the caliper and the small hex head screw holding the rotor in place. The ball joint separator tool I have has worked for every job I've done in the past (W124 tie rods, W210 upper and lower ball joints, and W163 tie rods) but it will not fit on the W163 upper ball joint. I figured, OK, let me remove the upper control arm. Well, in order to do that, I need to remove the shocks otherwise the upper control arm bolts won't come off. I wasn't willing to remove the shocks.
The ALL DATA procedures I obtained from this list are helpful but in many cases, not accurate. For instance, when replacing the motor mounts, it says to remove the viscous fan. My vehicle does NOT have one. According to another list member (when I mentioned the procedure is for a V6 engine and I have a V8) it also says to unbolt the compressor and move it forward to allow enough room to remove the driver's side mount. Not so, there is plenty of room to remove the mount without moving the AC compressor.
So, how can I:

1)Remove the front rotors? Are they simply stuck? I did spray Liquid Wrench and used a hammer.
2)Remove the upper control arm ball joints so I can remove the steering knuckle?
3)Will the front axle pop off the steering knuckle easily?

Thanks!!!

 

[APKhaos]

The rotors can be stubborn. Its just corrosion and nothing serious. You need to replace the axle nut first, of course. Ideally, use a soft hammer [nylon face or better still a sand-filled hammer], and rotate the rotor as you coax it off. Once the corrosion breaks it will pop off nicely. Use some copper-based anti-seize when you put the rotors back on.

 

[Sergio]

Thanks. Does the axle nut need to come off in order to remove the rotors_ I would NOT think so (at least on the '99 ML430 they did not). Why does the axle nut need to be replaced? Is it one of those "one time use only" items?
I did hit the rotor with a plastic/nylon hammer and rotated the SOB but it would not come off. I didn't want to brake anything so I stopped.

 

[43sqd]

Thanks. Does the axle nut need to come off in order to remove the rotors_ I would NOT think so (at least on the '99 ML430 they did not). Why does the axle nut need to be replaced? Is it one of those "one time use only" items?
I did hit the rotor with a plastic/nylon hammer and rotated the SOB but it would not come off. I didn't want to brake anything so I stopped.

If you are having a hard time with the rotors, place a block of wood on the back side of the rotor and strike it with a heavy hammer.

The axle nut has to be removed so you can remove the steering knuckle. It has nothing to do with the rotor removal.

To remove the upper ball joint from the knuckle, with a heavy ball peen hammer strike the area in red.

They recommend replacing the nut for fear that it might come loose. The choice is yours.

Also remember that the lower ball joint must be pressed out by a machine shop and the installation requires a special tool/wrench to tighten the locking nut for the replacement ball joint.

 

[APKhaos]

OOPS! The Maestro posted while I was typing this. Luckily for me we agree that in this case 'the bigger the problem, the bigger the hammer required'.

Does the axle nut need to come off in order to remove the rotors

No.

Why does the axle nut need to be replaced?

The tightening torque is high, and the nut stretches a bit. I don't have the torque spec, but you don't want it to be under tightened. Maybe use a long breaker bar to put as much force on it as you can at home, then get a new nut installed at a shop with the correct torque value.

I did hit the rotor with a plastic/nylon hammer and rotated the SOB but it would not come off. I didn't want to brake anything so I stopped.

You won't break anything. It may take a bit of brutality to break it free. Work around the rotor to avoid cocking it. It may take a heavier hammer with a block of wood to protect the rotor surface.

 

[Sergio]

Got it. Pretty much what I thought but when I noticed that the rotor was not moving, I thought maybe on the '02 models they redesigned them so that the axle nut would have to come off. I used an air gun to remove it and reinstall it. While not torqued to spec (and I will), it's very tight.
I don't understand how striking the area in red will remove the upper ball joint. The joint is installed/removed vertically and the area in red is perpendicular (horizontal) to the joint. Will it loosen the joint and then it becomes easier to pull it up?
The lower ball joint should come off with the tool I have and I did purchase the tool necessary to torque the nut that holds it in place to 300 N-m.
Thanks again!

 

[FAR888]

OOPS! The Maestro posted while I was typing this. Luckily for me we agree that in this case 'the bigger the problem, the bigger the hammer required'..

Ha ha ha - This happens to me all the time.

I would post a reply just as 43sqd or Witek also respond and to my horror my 'advice' is totally at odds with or not half as detailed and professional-sounding as their response!

I find myself speedily looking for the 'delete' button before anybody replies quoting my 'advice' in the next thread!

:big laugh: