So I've gotten most of the way through replacing ball joints and control arm bushings, but have gotten stymied at the last step.

I can't get the ball joint up the last 1mm into the steering knuckle hole, so that I can comfortably insert the bolt to tighten the ball joint on. The issue is that the groove that is carved into the ball joint is just wide enough - if the ball joint shaft isn't all the way up, the full cross section of the ball joint shaft is visible in the bolt through hole. I've already busted the threads on one bolt trying to pull the bolt through (and the ball joint shaft up!)

I've tried jacking the control arm up, but only against the force of the strut, not with the spring in play.

I also tried cleaning up the top of the hole the ball joint shaft fits into - it looks like plastic + rust at the top. When I remove the ball joint, there are some beginning signs of wear on the top, as if the top of the hole is interfering with the shaft going up all the way.

I also tried sticking a screwdriver into the gap (intended to help you remove a frozen ball joint shaft), but I don't think it had much effect.

The only thing left I can think of doing is :

- take the tension off the spring compressor (right now the spring is compressed for safety)
- jack the wheel up right under the control arm

In theory this would place more 'weight' on the ball joint, but at the risk of having the spring pop out if the ball joint fails downwards.

Your thoughts would be greatly appreciated - I'm looking forward to getting the old girl back on the road!

Bruce

1989 190D 60k miles.

Hmm...
there are no DIY articles in the wiki on the 201 or the 124 which is similar...
can you take pictures of what you are up against? have you removed the antisway bar connection to release tension?

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Can you pull down on the upper connection?

__________________
Jim

I tried pulling down on the wheel, but couldn't get any more movement. I will try to get some pictures tonight.

The sway bar is disconnected, so that's out of the running.

It is easier with the wheel off.

The upper knuckle should be attached at the upper control arm which, with the sway bar disconnected should be easy to pull down until the ball joint has enough threads to catch. You should be able to raise the lower control arm with a jack.

__________________
Jim

Sorry, terminology - the wheel is off, I was pulling down on the brake disc / steering knuckle.

There is no upper control arm on the 190D, it has a strut. I did jack the lower control arm up, and then leaned on the brake disc / steering knuckle, but couldn't get enough weight on to get the ball joint in the rest of the way.

I'm not sure I'm understanding completely what you're saying but unless there's tension of some sort, an incorrect part or a part defect, it's really straight forward.

Are you sure you alligned the marks on the new ball joint and the control arm?

I would release the spring compressors enough to put force on the control arm.

I have no clue what is also going on. But if I am reading right I want to make sure you do not have any part of the bolt in place. Some joints have a safety feature where a grove is tapered in where the bolt passes by. This is in the case of the bolt becoming loose, with the groove the ball joint can not come out unless the bolt falls all the way out. If the bolt is there when inserting, it will not insert.

Wild guess here.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

Lifeisabeach - about the markings, I roughly aligned the marks. I figured the purpose of the mark on the ball joint was to ensure that the indented portion of the ball joint shaft faces in towards the engine (so that the securing bolt on the steering knuckle can fit in). Given that the ball joint is relatively free to rotate, those marks don't have to be lined up perfectly - did I miss something?

B.Reilly - that's what I'm thinking I'll try tonight. I'm also going to see if there is any more gunk on the top of the female part of the connection in the steering knuckle, to see if something there is preventing the ball joint shaft from going all the way up.

LandYacht - The groove you mention is exactly the issue here, but don't worry, I don't have the bolt in when I'm trying to get the ball joint shaft (with groove) in place - I'm only adding the bolt after it is in place.

An old trick I used to use when I was working as a tech, loosen the spring compressors and jack the balljoint up so it is compressing the spring. If it won't drop in, take a large hammer or maul, and whack the side of the balljoint to cause the balljoint to vibrate up into place, then you can insert the pinchbolt.

Success!

The key was that the ball joint was restricted from traveling up the female shaft on the steering knuckle by caked sealant / epoxy (squirted in there to prevent rust). Looking from below, the dome of the female shaft looks just like metal, but in fact chipped out as epoxy.

Once I got that stuff off, the techniques you guys recommended for getting enough leverage worked great.

Now the only question is: What should I use as a sealant, to squirt in the gap between the arms of the pinch joint?

I've always used Moly grease. Prevents rust and doesn't interfere.

I use Fluid Film on everything.
Non petroleum base and won't wash off.