F11 520d DIY - Rear Lower Arm Balljoint Replacement - On the bench. UPDATED

[Andrew]

This is a guide on how to replace the rear balljoint on the lower arm on an 2015 520d F11.  The same balljoint is used on all F10, F11, F07 version of the 5 Series plus the 6 and 7 Series along with some posh Rollers too of similar vintage.

Part #13 in this link

The lower arm used in this is unique to the F11, but I do not believe there will be much difference in the arms used on the F10 saloon.

O.k. so we’ve got this easy as the lower arm is a good used replacement and is on my bench for this work instead of fixed to the car.

After @VPCAPTAIN's lower arm lost a fight with a raised manhole cover the anti roll bar link bracket broke off the arm. As the cost of a new arm made him break out in a cold sweat, a complete used rear F11 hub assembly was sourced for £80. The lower arm was removed from the rest of the parts and we took the opportunity to replace the balljoint as a new one could be had for £20.

 

Tools needed

5 Series Balljoint tool
Generic Bearing and Bush removal/insert tool
Spanners and sockets for working the above tools
Wire brush
Screwdriver
Hammer
Stanley knife

Bespoke 5 Series Rear Balljoint tool (<£30 from eBay)

Generic Bearing and Bush removal/insert tool.

 

Parts needed

Balljoint                        33326780438
Snap ring/Circlip          33321091687

If buying an aftermarket balljoint, not all of them come with the snap ring so check the part ordered. The febi part here came with the snap ring.

 

Wire brush around the area of the old snap ring to aid it coming out. I used a wire brush wheel in a drill. This cleared the muck away so I could see the gap in the snap ring.

To allow the snap ring to be prized out, I mounted the arm in a vice using a rag to protect the arm. With a few lights taps with a hammer on the end of the screwdriver the snap ring was beginning to come out of its groove in the balljoint. I made some marks on the arm to show where the snap ring sits, this helped me ensure I pushed the new balljoint in from the correct direction!

Came out quite easily

To give me a firm surface to push the old bush out I started to remove the rubber gaiter on that side.  There are two wire clips holding the gaiter on, one at the top and bottom. This isn't essential but it prevents the possibility of the cups moving when pushing the balljoint out.

I cut the rubber gaiter off with a Stanley knife

Old gaiter removed

A 50mm dia cup was used as the driving cup to push the balljoint out, it needs to be a whisker smaller in dia than the balljoint so the cup passes thru the hole in the lower arm.

A 70mm cup was used as the receiving cup with a 14mm threaded rod and the slack taken up,

once the pressure got too much the arm was mounted back the in the vice…. We were putting a fair amount of pressure on the threaded rod and we’ve got form for breaking these so we decided a squirt of WD40 might ease things along as there was no sign of it moving.

Another heave on the tools there was an almighty bang and I thought I had broken another threaded rod but no, the bush had started to move thanks goodness.

It’s out.

Compare old with new, the balljoint gets inserted from the rear of the arm forwards. Groove for snap ring is at front and the flange of the balljoint is to the rear.

Power wire brush both sides of the arm where the new balljoint will be installed.

We start the install, using a pair of cups, the smaller one pushes on the rear of the balljoint and this larger cup allows the balljoint thru on the front side (top in this picture).

This is where we hit a problem. The balljoint just wouldn’t go in square into the arm. Time for a re-think. I suspected that because the distance between the two nuts on the threaded rods were so far apart there was scope for the bar to be off centre slightly and made the balljoint go in squint.

We then invested in a specific 5 Series Rear Balljoint tool which has specific shaped cups to suit the balljoint and more critically are shorter.

Start again a few days later with the correct tool.

With a few moments and not much effort needed the new ball joint was almost fully installed but I had hit high resistance and was scared to put any more load into the threaded rod for fear of snapping it. I was making my 700mm long ratchet bend putting beef into it.

Its not home yet but there is no way I can get it to go further.

Stop and think things thru again

Checking the receiving end of the insertion tool, it just wasn’t quite deep enough to allow the balljoint to fully pass thru the arm. You can clearly see the snap ring recess, the tool needs to cover over that to allow the balljoint to be pushed far enough 

So a suitably sized bearing cup (64mm) was found and the threaded rod passed thru and again within moments and with little resistance the balljoint was pushed fully home.

Phew hard bit done and there is the gap for the snap ring to ‘snap’ into.

I start the snap ring in its slot at 9 o’clock and work clockwise round gently pushing it into place with nothing more than a small screwdriver.

That’s it its installed fully.

 I think the specific 5 Series Balljoint tool was developed for older generations of 5 Series where the ball joint might be of a slightly different size so it would fit into to the receiving cup of the tool, where as I had to use a hybrid version of both my tools to make it fit.

This is what the lower arm looks like with the new bolts ready to fit to the car.

With a new roll bar drop link and an integral link. This is what we will fit to the F11.

And with the rest of the 2nd hand hub and arms so you can see how it all fits together. 

We will only replace the lower arm on the car, leaving the hub with driveshaft/bearings and upper arms in-situ.

Will keep you all posted how that job goes....

 

[Matthew]

Great job doing the work and documenting the process with remembering to take photos along the way, this all takes skill!

[Andrew]

I should add that when using these tools that rely on threaded rods to generate the forces involved, make sure you lubricate the threads with a good quality high load grease such as CV joint grease with molybdenum in it. 

It does make a difference and you are less likely to snap a threaded rod. 

You can see my tin of grease in the background of some photos 

[Andrew]

Now that we have swapped out the broken lower arm for the used replacement, I had a play with removing and replacing the old balljoint in the broken arm, again on the bench using the specific tool along with one of my bearing/bush cups with an internal diameter of 54mm, outside diameter is 64mm.

Wire brush around the snap ring so you can see the exposed ends.

Lever this out with a big flat screwdriver.

With the snap ring out the way, spray in some penetrating oil to help things along.

This time I was able to push the driving cup from the tool over the rubber gaiter of the balljoint without removing it. Make sure the force thread of the tool is lubed up with some heavy duty grease.  It makes a big difference greasing up force threads.

Fit the receiving cup over the force thread and start the nut.

I gave the driving cup and suspension arm a few love taps with a hammer just to help things along.

Start to tighten the force screw nut, and with considerably less effort than last time, the balljoint started to move.

It's out.

Dismantle the tool to extract the balljoint.  It's undamaged by the specific tool confirming that you do not need to remove the gaiter to get it out, but I was not using the specific tool back then.

Clean up the inside of the lower arm with a wire wheel.

Because this is just for practice and entertainment value, I re-fit the old joint I've just removed.

Use the two different cups in the kit to drive in the balljoint.

I was able to draw in the balljoint using a standard length 1/2" ratchet until I hit resistance. Note the gap between the balljoint and arm on the opposite side from the ratchet.  This is due to the balljoint hitting the receiving cup and refusing to go further. 

This is as far as I can get the balljoint with the specific tool.

Using my bearing/bush tool, I use a cup of ID54mm OD64mm to allow the balljoint to be driven fully home.  Note gap again on the driving side of the tool.

Now pushed fully home.

Gap for snap ring.

Which I refitted, just to see if I could.

It took me 25 mins to remove and replace.

The specific tool @VPCAPTAIN bought is this one. 

https://www.ebay.co.uk/itm/305381186971

Now please note that the seller DOES NOT claim it will fit an F10/F11. 

As you can see the tool will remove it easily, but it needs a little extra help/additional tool to fully install it.

Arm is sitting in my trailer waiting to go to the skip.