[vexingv]

(2016 M235 Xdrive)

Over the past couple of weeks, after finding drops of fluid/oil in the driveway/parking spots, with help on the forums in another thread, the most likely conclusion is that the leak is coming from the bushing on my front passenger side. I noticed the driver side also had some dried fluid by the bushing suggesting it may have leaked before. The drips on the passenger side seem to have subsided in the last few days; maybe it has completely leaked at this point??

I understand that it is easier to replace the whole arm as one would need special hydraulic tools to replace/press just the bushing itself.

1. How difficult of a job would replacing the arms be to do oneself? I have a set of socket wrenches, cordless impact wrench/sockets, torque wrenches (40 lb-ft to 150 lb-ft), and other basic tools. The repair would be performed at home in the driveway/garage with the car on jack stands. I don't have a ton of automotive repair experience (have done brakes and oil changes), but enjoy tinkering.
1a. What are some other parts/tools that i would need for this job? Any links for good resources/tutorials?
1b. Alternatively, what's the ballpark cost for a dealer/shop to do this repair?

Also, i understand that both driver and passenger arms should be replaced together at the same time.

2. Do both upper and lower arms need to be replaced at the same time too?
3. Are there any performance upgrades for these parts? (The only ones i see for my xdrive model are OEM Lemforder arms)

Just to confirm, In the pic below taken from the front passenger tire well:
-red circle: leaking area
-green circle: upper control arm?
-blue circle: lower control arm?

[msendit]

Hey, yes, that's the TS and the blue circle is the LCA.

And yes, you'll need some sort of press if you just want to change the bushings. Regular hand tools should be enough if you decide to swap the full arms.

Swapping the arms is a pretty easy job, only slightly more complex on the x-drive (you have to undo 3 bolts, not 2). You can definitely DYI, but make sure to get an alignment after that.

I just looked, last time I had both control arms and the tie rods on one side changed, monoball transferred from the old TS, and my local race shop billed me for ~1 hour. Plus another hour for alignment.


https://www.newtis.info/tisv2/a/en/f...ounts/KHLy4z3Y

[vexingv]

So I should replace both tension strut and lower control arm on both sides at the same time? Do I need to take apart/detach the lower arm to do the upper/tension strut?

I don't know or can't tell if the lower arms need replacement at this time (my car has just under 40K miles) but I guess if I have to take it off, I might as well replace it too...
FCP euro does have a kit that has all arms, which is another $100 or so more than just the tension struts themselves.

[FaRKle!]

Originally Posted by vexingv

(2016 M235 Xdrive)
1. How difficult of a job would replacing the arms be to do oneself? I have a set of socket wrenches, cordless impact wrench/sockets, torque wrenches (40 lb-ft to 150 lb-ft), and other basic tools. The repair would be performed at home in the driveway/garage with the car on jack stands. I don't have a ton of automotive repair experience (have done brakes and oil changes), but enjoy tinkering.
1a. What are some other parts/tools that i would need for this job? Any links for good resources/tutorials?
1b. Alternatively, what's the ballpark cost for a dealer/shop to do this repair?

Also, i understand that both driver and passenger arms should be replaced together at the same time.

2. Do both upper and lower arms need to be replaced at the same time too?
3. Are there any performance upgrades for these parts? (The only ones i see for my xdrive model are OEM Lemforder arms)

1) The job's not terribly difficult, the most difficult parts are undoing the front axle collar bolt (high torque), and maneuvering the front axle out of the knuckle and out of the way so you can undo the nut holding the tension strut (official name for that control arm) to the knuckle. It's definitely easier (and faster) to just replace the whole arm than to replace the bushing.

1a) If you want to do it "by the book" you'll need new collar bolts and a torque wrench capable of >150ft-lbs (200ft-lbs wrench will work). Also a large breaker bar to break the collar bolt loose. My Milwaukee M18 Fuel Mid-torque impact can't break that bolt loose.

2) Depends on the mileage. If your car is like 80k miles it'd make sense to replace the wishbone (LCA) too, but if you're only at like 40k, you don't really need to. Also, if you're lower mileage I wouldn't bother replacing the other side if you don't need to.

3) You can upgrade the bushings to monoballs to greatly increase steering feel and response. There will be some more NVH though (primarily through the steering wheel). VAC Motorsports and (I think Turner) sell complete arm assemblies with their monoballs pre-installed. If you want caster adjustable, KMAC and SPL make a monoballs with that feature, but those don't come in complete arm assemblies.

If you're just replacing the arm with an OE/OEM assembly you might not need an alignment. When I put my KMAC monoballs in, I set the distance from the mounting hole to ball joint the same as the OE arms I pulled off and when I went in for alignment my caster was the same as before on one side, and only off by like 0.1deg from where it was on the other.

[vexingv]

Using realome, I've figured out the part #s for the tension strut, but using the exploded parts diagram (https://www.realoem.com/bmw/enUS/sho...diagId=31_0993), I'm not sure what additional replacement bolts/nuts/screws I will need to order as well for this job.

Can anyone help?

[msendit]

Originally Posted by vexingv

Using realome, I've figured out the part #s for the tension strut, but using the exploded parts diagram (https://www.realoem.com/bmw/enUS/sho...diagId=31_0993), I'm not sure what additional replacement bolts/nuts/screws I will need to order as well for this job.

Can anyone help?

You can get away without changing the fasteners. If you want to really do it by the book:
- #12 on the diagram you showed -- the nut to hold the TS to the knuckle (that end of the TS has thread, so you only need the nut)
- #11 -- the bolt that goes through the bushing and fastens that end to the subframe
- #3 and #4 (bolt and spring) here [1] -- which fasten the output shaft to the hub

[1] https://www.realoem.com/bmw/enUS/sho...diagId=31_0890

[este]

So just changed mine out as well as lca for the m3 pieces. The difficult part (if x drive is the same as rwd) is the passenger side has the battery cables literally right in front of the bolt the only was I was able to take off was with a 18mm regular spanner wrench using the circle end.

I had to remove the wheel well( just a couple 8mm screws) and bottom plastic tray to have completely clear access to bolt. When reinstalling I had to make sure I pushed the battery cables out the way to avoid the pinching the cables.

[XutvJet]

There's really no reason to replace anything but the tension strut unless you see damage/fatigue to other components. Also, there is no need to do an alignment either as none of the adjustable components are changing or being impacted. Sure, some alignment setting might change by a fraction of a degree with this work, but it's hardly anything that would cause the steering wheel to shift, a tire to pull, or create excessive tire wear. Now if you decided to replace the TS with the M-series TS, then yeah, an alignment is definitely needed. OEM stuff? Nope.

[FaRKle!]

In case you haven't done the tension strut replacement yet, I finally had an excuse to make a video on it.

[vexingv]

Originally Posted by FaRKle!

In case you haven't done the tension strut replacement yet, I finally had an excuse to make a video on it.

That was a really great video walkthrough on the installation, thanks for sharing. I just got all my parts at the end of last week from FCP Euro, so I'll be working on the car this week (as well as installing new SS brake lines and brake fluid flush). It was only until the end did I realize you were working on a 3-series wagon. What tension strut did you use? For the F22 at least, I couldn't really find any upgrade/performance parts so went with OE tension strut/bushing.

[FaRKle!]

Originally Posted by vexingv

It was only until the end did I realize you were working on a 3-series wagon. What tension strut did you use? For the F22 at least, I couldn't really find any upgrade/performance parts so went with OE tension strut/bushing.

The F2x and F3x vehicles use the same tension struts. I also bought the OE kit with all four arms from FCP Euro. I changed out the bushings in all mine for adjustable units though (KMAC camber adjustable bushings for the wishbone/LCA and KMAC caster adjustable monoballs for the tension struts). I've installed a few of the caster adjustable monoballs for other people after they went full release and none of them were as easy to press in as the one I had where the arm started to walk off of it. I also spoke to KMAC's proprietor during the beta test period and he confirmed that they increased the OD of the monoballs a bit.

As far as other aftermarket options, Powerflex makes some poly tension strut and wishbone bushings, VAC motorsports makes non-adjustable monoballs for those arms too and offers them pre-installed in the arms, and lastly SPL makes their own arms and makes monoballs you can put in the OE arms too.

Actually I just remembered, I have a brand new set of the Powerflex xDrive tension strut poly bushings if you're interested in them. The tension strut bushings is the major contributor to steering feel. I see we're both in the Bay Area (I'm in the tri-valley).