P3 lower control arm replacement procedure writeup (XC70 2008)

[wasaabi]

I just went through replacement of my front lower control arms (along with tie rod ends and sway bar links) and had some moments of frustration until I uncovered the order, which made it much easier. My 2008 XC70 has 181K miles, and everything in the suspension is original. For the benefit of others, here are the steps that worked for me:

- The day before, liberally apply rust penetrant on all bolts/nuts that will be removed
- Jack front of car on jack stands, take necessary redundancy precautions (the wheel you remove with some added wood under the car is a good start).
- Assuming driver's side first, so remove that wheel.
- Insert key to release steering lock.
- Turn steering all the way to right
- Apply rust penetrant again on all bolts/nuts that will be removed
- Work on getting out tie rod lock nut released. Mine took some work. Adjustable wrench + hammer + rust penetrant helps.
- Loosen ball joint nut with breaker bar (mine was quite rusty)
- Unscrew it fully, then screw it back in several turns
- Hit side of tie rod base on knuckle with good weight hammer a few times, then strike top of nut you just screwed in several times until tie rod pops out.
- Unscrew tie rod, count number of turns to release. I marked the inner tie rod and the number of turns with a marker right on it.
- For extra flexibility, at this point, if you want, you can remove the top nut of the stabilizer link.

Now we can work on the lower control arms. The order of removal will be:
1. Two rear bolts with nuts on top by stabilizer bar. Nuts on top can be held in place with 21mm combination wrench held at just the right angle. It helps to have an assistant to help keep them from spinning. Break free the bolts on the bottom using breaker bar, then remove the bolts from below. Take the nuts out from the top.

2. The single central bolt (welded nut stays in place). Use breaker bar.

3. The sandwich bolt that hold the ball joint together.

- Once fasteners are removed, use pry bars to pry out the rear (where the two bolts were) and then the central area (where the one bolt was). This is a bit tricky but not very hard with a few pry bars. The result you want is a lower control arm loose and hanging from the ball joint.

- Release ball joint. Hammer sideways a few times on socket, then hammer down on old control arm near socket. Wear ear protection. Several blows will get it out.

Now that all is out, this is a good time to remove the other nut of the stabilizer bar link and replace that. I highly recommend using new bolts/nuts for everything. My ball joint bolt was quite nicked up. It's cheap insurance to replace it all.

Going back in with the new control arm is where I got stuck until I figured out this method:

1. Turn wheel to opposite side (drivers wheel pointing LEFT). This is to allow clearance for socket to sit exposed while wedging in the new arm.
2. Get center part of the control arm positioned so that you can start the single bolt by hand. The key to not going crazy is to get this bolt in first, when everything else is loose. While positioning this, the ball joint is going to be pointing up, next to and in FRONT of its socket.
3. Once you get that bolt in fully (but not torqued yet), you can pry down the control arm (use the handle of break bar in the gap above the center of the arm for leverage), while moving the wheel by hand so that it points RIGHT, so that you wind up with the ball joint on the other side of the socket (next to the socket, but behind it).
4. Now you can rotate the back of the control arm into place, hammer lightly as needed to position it into the right spot to put the two bolts/nuts in. This should be easy to do with the ball joint where it is. Tighten but do not torque.
5. Now we are ready to pop in the ball joint. I used the back of the breaker bar again in the gap to pry down the control arm so that the ball joint is beneath the socket entry. A little bit of adjusting to get the socket aligned, and now a simple jack (like the one in the trunk) can be used to seat the joint in the socket.

- Now that the arm is in place, torque everything correctly.
- Attach new outer tie rod, matching previous number of turns and then locking into place with lock nut (note that the inner tie rod does have some teeth to grab onto to prevent it from turning--they are all the way in by where the boot starts, and I used an adjustable wrench and some bricks to wedge it into place while tightening the lock nut
- Use the jack again to help seat the tie rod in the socket and hold it while torquing its nut.

Even though I followed the "number of turns" rule with the tie rods, the alignment was really off afterwards. Toe-in was really bad on one side. So I used a measuring tape to approximate alignment between the two front tires, turning the inner tie rod as needed on the bad side. That made a huge difference. Alignment is scheduled for next week...

I hope this helps someone. I got really frustrated trying to get the control arm in because I tried to do the two back bolts first. There is no way I found to get the front bushing properly aligned if the back is in first. It has to do with the angle. So getting the center bolt in first and doing the switcheroo with the wheel direction and ball joint location was the key. Once that was figured out, this was not a hard job. And the tightness of the suspension feel is so worth it afterwards!

[cbaccus]

You are a savior. I have been fighting with this all day yesterday and not having amy success. Going to try your method later today. Will report back with some photos and results. Thank you for sharing this method as I tried the back two bolts and knuckle trying to get the last section in and nothing worked. Some YouTube video showed jacking up the rotor to slide it in but it slides out, not in. So I don’t know how that worked for that person because he never showed him putting it together. The video cut that part out.

[cbaccus]

I didn’t have any success getting the ball joint in. I tried it with a couple jacks including a scissor jack and hydrologic, but kept pulling and rolling away. Closest I got it was the photo, eventually I ripped the ball joint rubber as it kept slipping. so now the control arm is broken. Taking it to my mechanic this week. Oh well, thanks for sharing this. Maybe others will have success.

[wasaabi]

Oh no! I’m sorry to hear that happened. It may be too late, at least for this side, but for future reference or the other side, the ball joint should be pretty easy to get in because once you flip the strut back over the control arm to the correct position, all you need to do is pry down the control arm a bit and allow the wheel assembly to rest right so that the socket is right over over the ball joint, then release. The ball joint will enter partially, and you only need to use the jack to get it fully in. I can’t quite tell from the picture, but it from the description it sound to me like the control arm and wheel assembly where not correctly aligned before trying to insert the ball joint. Prying down the control arm with a lever (can use anything, like a long breaker bar or lever) gives you the flexibility to align things. The prying lever should apply force to the thick metal part of the control arm (not at the ball joint). Can get a helper to hold the lever but I didn’t find that was needed.

[wasaabi]

One more thing I will add that might make this easier is to pop out the axle from the wheel. This gives much better mobility of the whole knuckle because the only thing holding it at that point is the strut mount. The guy in this video shows the axle punching out process (although I am not so sure about the rest of his work…).

[carcomptoy]

Is there another way to hold the control arm down besides the pry bar?

Bruised myself up replacing the LF control arm on my P3 XC60, and can't help but wonder if holding down the c.a. with a long metal rod with the slot on one end and either the strut mount or hooking onto the strut assembly would be possible and much less strenuous (picture below for reference )

[wasaabi]

With the correct length pry bar it takes very little force to hold it down, but you might need a helper because there is not much else you can do while holding it. I tried using a chain around the control arm and connecting that to a bar, but this proved unnecessary. My guess is that either the pry bar you are using is too short, or you may not be inserting it into the most ideal spot.