s40/v40 new bottom ball joint size problems
 

Just to alert folks to this...I have a 99 s40 and I have replaced a couple of bottom ball joints in the last ten years. I bought a new one last week and tried to fit it yesterday..too small..it measures 39.9mm around the knurled area (so it grips when pressed in) but the old one measured 40.3 mm. That .4 of a mm makes a massive difference..the new balljoint just flopped about in the control arm space.. I tried three different manufacturers and they were all the right ones for the car but they were all 39.9 mm..

I would be very interested if anyone else as had this problem..I asked the guys at work for some shim steel (0.1 mm) and made shim for it, held it on with superglue and eventually managed to press it in with the aid of some copper ease. The circlip was popped in and it looks like its all good. The ebay guys I bought it for swore blind it was for my car and this does check out. They refused to take it back, but did reimburse me. What a hassle though..nightmare to fit..Also, getting the balljoint 19mm nut bolt on and off..there is no clearance for anything but a 19mm open ended spanner, so you effectively cannot torque it accurately, but it is a lock nut so it should be OK..the old was so hard to remove I just hacksawed it off..

What a pain in the arse...

That bodge sounds dangerous to me and will fail an MOT just buy a new arm from Volvo as they don't supply the ball joint for a reason ..

As Clan said it may/will be deemed dangerous come mot time, complete arms are dead easy to fit .

That is if the car and driver survive until MoT time.

I've found that even if fitted properly they can come loose when pressed in. Got it tack welded back in and was fine after that, think the issue was someone had previously done the same so didn't like getting a ball joint pressed in again.

My car has done 143000 miles and whilst the control arm rubber is old in the front and back bushings, there was no splitting. The control arm bushing wear is subject to style of driving as well as whether it was fitted correctly (torqued with the car on the ground). The balljoints are intended to be pressed in, but obviously with nowhere near as much force as that of a bearing (eq. of at least 6 tons). The first balljoint I had to replace in 2015 showed internal play only after 120000+ miles which is quite impressive. I pressed in the new one and it needed a heavy duty vice with a three foot extension to do it. It stayed in for four years before it began to show some play inside the joint (not a very good quality one). It took the same three foot extension treatment and a great deal of force to remove it. The shimmed one I have just pressed in took even more sustained pressure to insert. Once in, the circlip is fitted which slots into groove and this provides added security. As to MOTs, In the last 10 years I have prepared 20 cars and the only failure was the CEM module which runs the lights which failed on the way to the test centre. In that time I have replaced springs, struts, various bearings (front and rear-drive), engine mounts and different types of balljoints.

when the joint is inspected at MOT , the following is a reason for rejection directly from the MOT tester's manual ...

"A suspension component with an inappropriate repair, or a modification which has seriously weakened the component."

It is down to the tester's opinion , but i doubt he will put his neck on the block to pass it .. They even advise of the engine undertray in place these days in case there is some fault not visible which has not been seen .

well, have struggled for some time and have given up trying to post a pic of my passed MOT with no advisories, 1000 miles after replacing the balljoint...you will just have to take my word for it...

A lower ball joint that comes loose is no fun.
I replaced mine last year. It came with a circlip but I couldn't get the clip on and was afraid that the needed amount of stretching it to get it on would break it.
So I looked on forums and every one said;- forget the circlip, the ball joint is pressed so tightly into the control arm that it is not really needed.
Yeah right! - A few weeks later I was driving home from a birthday party, not fast, maybe 30 miles per hour,-and right then a loud bang was heard and the car jumped about a foot sideways.
I stopped at the shoulder for an inspection, and saw that the control arm had let go of the ball joint. Had that happened at 60 -70 miles per hour the car would have gone into low orbit.
I had it towed home and welded a solid piece of steel on to the control arm holding the ball joint in place.
Buy a kit with the ball joint and the control arm and stay alive.

if you could not get the circlip on, then possibly the joint was not fully seated. Also, I found the only way the circlip will go on easily is to remove the rubber boot on the balljoint. I don't thing it will fit over the boot without deforming.
Once you take the boot off and fit the circlip, here is only a very narrow margin to fit it in terms of the seating. You should be able to look at the base of the joint as it protrudes from underneath the control arm and it should be obviously pressed all the way in. If it is not, that is, there is any gap between the lip/shoulder of the balljoint and the control arm, the circlip will not fit on as there is insufficient clearance on the groove on the joint for it to engage. It takes some serious pressure to get them to seat. I used a workshop heavy duty vice with a metre extension to the vice bar. This is around the limit of pressure you can exert from a workshop vice without bending the arm. Hammering them out takes forever, which was what I did to remove the factory one, before I made some steel sleaves (from old 940 exhausts) to use the vice.

If you buy the control arm with the ball joint already fitted it will have been pressed in. There are quite a few other cars out there (like a fair few Hondas) with pressed-in balljoints. The last one I pressed in lasted 18,000 miles, which is a poor show for a suspension balljoint, they still should last more than that, but it was fairly cheap. The factory joint on the other side has been on 20 years and passed the MOT and that was pressed in.

You can avoid the problem completely by buying a 940 which has a bolt on suspension balljoint arrangement on the strut base and no flat-stamped style control arm. My 940 suspension balljoints have lasted 30 years.

Welding should sort your s40 though...if you bought a good quality balljoint then you are good for 30-40K miles before you need to replace the arm. Hopefully the heat from the welding will not have liquified the grease in the balljoint...