99 s40 lower balljoint replacement-pitfalls

[Miketwovolvos]

Just passing this on for the benefit of those with a clunking front end over speed bumps and play in the lower control arm balljoint. Haynes says you can't replace them, but they are pressed into the control arm and the balljoints are available cheap 8 quid or so or better 12-14 quid. In my experience with Chinese-made stuff, don't go cheap. My first prob was that my Chinese-made balljoint scissor type splitter snapped, so I struggled to remove the joint. You can only use an open ended spanner to undo the bolt (19mm)on the balljoint, which is not that easy as it has a plastic threadlock type thing in it. Improvised a tool to crack open the balljoint and then its obvious why the control arm has to come off to get the balljpoint out, there is no space to work around the hub/strut assembly. The pivot bolt at the top of the control arm is a 17 mm long nut and bolt and its torqued at 66 so its not too hard to remove, although you might have to remove the bottom engine cover to get at the nut. The back bolts that (17 again I think, 66 torque)fit to the car body just go into captive threads in the body so they are not too hard to remove. The problems start when you try to remove the balljoint. I tried pressing it out with the vice, but no chance. A hydraulic press is ideal, but you can whack it repeatedly with an old socket (over it) with a lump hammer. Support the edge of the control arm on some wood. Eventually it comes off, but a bit of heat to the end of the arm really helps this plus some WD40. Next, clean up the arm and check the bushings. If they are OK, I treated the control arm with phosphoric acid (40%) then some underbody paint. Youtube guys say you can tap the joints into the arm with a hammer-Ha Ha Ha, no you can't. If you measure the new balljoint it is slightly oversized, but it has little ridges on the edge which collapse when it is inserted to really grip the arm. This is definitely a once only insertion, so to speak. Indeed, pressing the joint in is not easy at all. I made a steel tube (from part of an old 940 exhaust) which fitted over and cleared the top of the joint and then used a thick washer on the bottom of the joint so I didn't distort the balljoint base . Then I put it in a vice. It is really a struggle to get it to go in straight, but with a little WD it will go in. Then getting the circlip on really finds your Chinese circlip pliers out...Next, get the rubber boot and degrease the inside. THen degrease the balljoint shaft and then fit the boot over the balljoint shank. This makes it easy to engage the balljoint shank with the hub without getting any grease in there, as it is a friction joint and no grease should be around. Then you can replace the control arm, by engaging the pivot first and getting the bolt through, followed by the back bolts. Then the balljoint, pivot bolt and rear bolts are all in finger tight, then its all torqued up. The balljoint nut should be 55 lbft but you can only get an open ended spanner in, as it will trap a ratchet ring spanner...(nasty) so that means just make it fairly tight. I use a Metrinch spanner, which does not stress the edges of the bolt, which really helps. Forgot to mention, that you shouldn't torque up fully the control arm pivot joint until the car is sitting settled on the road, which by the side of the road is a pain. I have to say that it was hard work without a hoist and I think its one of those jobs you do if you are a bit of a fanatic, have really good tools made by an organisation other than a Chinese factory or if you are a bit broke or marooned on a small island. I am sure many of you out there would do it quicker though!