W124 - ball joint popped out of knuckle while changing pinch bolt
 

Hello all,

I am seeking help with a rather sticky situation that I have gotten myself in.

Last week, I have changed the driver's side LCA on my W124 - I followed all the safety procedures and the job proceeded rather smoothly, aside from a few stuck bolts. Replacing the LCA, I noticed the pinch bolt is rusty. I ordered a new part from the local MB dealership and temporarily assembled the LCA using the old pinch bolt. Unfortunately it's my daily driver and the ETA on the bolt was several business days.

Yesterday the bolt came in. Wanting to change it, I jacked the car up, put a jackstand under the LCA as near to the ball joint as possible and undid the pinch bolt. Unfortunately, I underestimated the force of the spring and noticed the ball joint slowly slipping out of the knuckle. In a moment of sheer terror I put the wheel back on, put a piece of wood under the joint and jacked the car down. Now I am stuck with a situation depicted in the photograph.

I have managed to get the spring compressor on, but it only compresses the spring so much - anything past what's on the photo and the compressor just slips on the coils when I try to compress the spring more. Jacking up the LCA does not work - the joint touches the knuckle, but I presume the spring force prevents it from going further in (I have centered the joint on the knuckle).

My question is - how do I push the ball joint back in / get the spring off without dying? I presume that if I put the jack under the LCA, undo the wheel and jack it down, the spring will come flying despite being partially compressed.

On a side note- I know this was not a smart thing to do and I should not have underestimated the force that the spring exerts on the LCA. Lesson learned - I guess I fell into the routine of mechanical work a long time ago and got too comfortable taking shortcuts.

If you choose to try this method it is at your own risk.

Leave the tire in place, put a floor jack under the control arm as close to the tire as possible. Jack the car up under the lower control arm and the ball joint stud should move into the knuckle and then install the bolt. Rotate/index the stud to accept the bolt before jacking it up.

Good luck and again this method is completely at your own risk.

Yup that should work. Be careful and good luck!

Hey guys, I will try that today - thank you for your help.

My only concern is that this is what caused the problem in the first place - the control arm was supported by a jack stand while the stud started slipping out of the knuckle.

If this solution does not yield any results, I thought about following the procedure below:

1) Leave the compressor in, try to give it a couple more turns with the LCA resting on a jack stand
2) Loosen the LCA bushing bolts
3) Secure the top of the spring to the perch with ratchet straps
4) Place the floor jack underneath the LCA, jack the vehicle up, place jackstands on jacking points
5) SLOWLY undo the floor jack and get out of the line of fire
6) Hope the spring undoes itself from the LCA notch

Obviously, I am not very keen on this strategy, but if I cannot push the stud in on the vehicle, I don't have many more options left. If anyone has a better idea, any help is greatly appreciated.

That spring is very long and under a lot of compression. If you have never seen a W124 spring in a box you wont know, its not like a regular chevy spring.

Even removing the control arms fully and making them almost vertical still holds the spring in its cup. Its that long. (be careful as you have disassembled the rollbar too, that bar limits the control arm downward swing)

Now to get this back into place, raise up the body of the car and install jack stands. leave the tire on, position a jack so you slowly raise the control arm up, once the joint butt is off the wheel rim barrel, the entire spindle will be free to move in any direction, have someone with mechanical skill and aptitude to position the spindle on the ball joint stud and then raise the jack upwards so it seats, then install the pinch bolt - make sure the whistle notch of the joint is lined up before you start any of the above.

The balljoint sits at a very sharp angle as the car has a 8 degree caster angle - so it wont go in easy and you will have to wrestle the spindle in the 1 and 7 oclock position to get it to line up.

Im not quite understanding how the car lifted itself off the jackstands? because I have done this job when I changed my W124 balljoints and put a jackstand under the control arm near the balljoint - The entire front of the cars weight was on the jackstands under the control arms.

did you not lower the car onto the jackstands?

Thank you for your advice! I have seen the spring before, as I replaced them on my previous W124 and helped with that on a couple of W124-W210 we were servicing back in the day while I worked in the shop. This is why I feel so stupid about causing this predicament, as I have done the procedure before and should have thought ahead. Should NOT have underestimated the spring force and taken any shortcuts. Definitely a lesson in humility.

I will retry the procedure you proposed, however previously the ball joint wouldn't budge into the knuckle when touching the top of the hole and the car kept going up. Might have something to do with the vertical notch in the knuckle being closed up and resealed with RTV, I should probably try to get it loose before the next attempt.

The car was resting on two jackstands, one near the jacking point and the other one underneath the LCA as close to the bushing as possible. Hence I am surprised this happened. Should have compressed the spring regardless I guess.

Resting as close as possible to what bushing? The LCA bushing?

The ball joint

Philly, Read the last paragraph in post #7. I'm reading it as the stand was at the LCA bushing no???

KJ, Z:

In a situation such as this, it may be necessary to resort to diagonal jacking of the chassis to cause enough weight to be transferred to the front corner.
Try placing a jackstand, set as low as possible while still getting it outboard as far as possible (tire clearance gets involved here), under the control arm. The farther out the stand can be set, the better.
Then jack under the diagonally opposite corner of the chassis (not under the suspension).
A greater percentage of the car's weight will be transferred to the front corner, and if all goes well, the spring will be compressed further than by jacking only the front corner.

My apologies, I meant the LCA ball joint, not the bushing.

Thank you so much for suggesting this - I will definitely try this method.

Be cautious when diagonal jacking,
vehicle stability may be reduced.

Good luck!!!

Further attempts to get the stud into the knuckle have been unsuccessful - I think the jackstand is not close enough to the ball joint - please see attached picture. Regardless of assumed strategy (car on jackstands + jacking up the LCA, jackstand under LCA and lowering the vehicle on the jack, all combined with diagonal jacking to shift the weight forwards), the stud does not go further into the knuckle. I have of course changed the position of the knuckle relative to the stud multiple times, even got it at the right angle, all to no avail.

I am considering two scenarios:

1) Loosen the sleeve further (I did pry it open some and cleaned out the sealant that I have applied during the previous installation) and loosen the LCA bushing bolts - I don't think they exert that much force on the assembly, but l'm theorising that this might give that small bit of upward movement I am lacking here.

2) Jack the LCA up, remove the tyre, put a jackstand much closer to the ball joint and CAREFULLY lower the jack. Obviously, I am a little hesitant about this option.^

Thank you for all the help so far, further suggestions are most appreciated.

As stated previously, if used this method/suggestion is at your own risk.

Leave the jackstand where it is, put another one under the frame rail on the side you are working on, jack up the other side of the car to get closer to level with the jackstand under the frame rail. Remove only the tire on the side you are working on, put a floor jack under the ball joint and lift. If one side of the car is higher than the other the angle will work against you.

Is the problem that distance won't close or the stud resists going into the knuckle? This ball joint stud was in that knuckle correct?

Could you put a chain, a breaker bar or pipe through the center of the spring and through the control arm and spring perch as a safety capture?

Good luck!!!