Adventures in replacing MB lower control arms

I had purchased all the parts needed to replace the lower control arms, thrust arms and lower ball joints for the front suspension on the old '04 MB S430.  Along with the help of my friend Gaba and my nephew Jacob, we were able to spend way too much time on getting the passenger side completed. This was completed back on July 1st.

That was a lot of fun, but ultimately we screwed up on several parts and ended up taking way longer than expected.  We also ended up stripping the upper control arm ball joint which made us reuse the stock upper control arm.  It wasn't in bad shape to begin with, so not a big deal.

November 4th

Fast forward a few weeks, and I finally had a day planned to complete this repair on Saturday Nov 4th, 2017.  I was so excited to get these new parts into the car finally.

I had requested help from my friend Gaba again - but he was not available to assist on this day.  There was also a neighborhood mechanic I had gotten in touch with, and he was able to come later on in the day.

I went ahead and got started, I set up the car in the driveway somewhat out of the way and started getting to work.

I got my beauty jacked up and on jack stands and removed the front wheel.

Things were progressing nicely.  I got the wheel splash guard out, and the front thrust arm replaced already.  I was at the point where I needed to pull out the old lower control arm, but I was somewhat stuck on getting the lower ball joint to pop off.

I did finally get it to pop.  Now all that was left was the lower strut set screws.  I managed to get the back one out without too much trouble.

This was the point where our Neighborhood mechanic showed up.  I was struggling to get the front set screw to let go, it was in there very tight.  I was bending my Allen wrench pretty badly and was concerned about possibly stripping the screw.

Our neighborhood mechanic went ahead and stepped in, and put a big wrench on it and stripped the screw.  I was calm, but so upset at this development.  in the mechanic's defense - I was heading down the path that would probably have stripped the screw too.

We stopped and went to all the local hardware stores to purchase stripped screw removal bits and hunting for a new M10x1.0 screw (which NOBODY has that size/pitch).

We worked on it a few more hours and called it a day - yet still stuck in place.

November 5th

We regrouped again looking to hopefully get this screw out, and ultimately were unsuccessful in our venture.  We decided at this point we needed to get the strut out of the car regardless.

All we were doing was just further stripping the screw.  Not much progress at the end of the day:

Day ended without any further progress.

Should be noted that the lower control arm was being replaced, and so we don't really care about it.  There is the option to get a new strut instead - but in the interested of not spending $$$$ to replace a part that we know works fine, I'm more interested in saving this strut instead.

Let me be clear - at this point the decision is to repair instead of replace.  If I was going to replace though - I found that O'Reilly's has a re-manufactured Arnott strut with Lifetime Warranty for $310 + Core.  I'd be all about it, but the thought of losing the core is the real bummer - especially since the strut functions fine.  The end result probably will be about $300 in tools and parts, and I'm actually more okay with that for now since the tools can be reused for future projects and repairs.

November 6th

Strut was placed in the trunk of the Cobra.  I was hoping to be able to take it to a shop and have it drilled out or somehow fixed throughout the day.

However:....

• I took it to my MB mechanic - and they were too busy to even look at it.
• I went to NTB - I was hopeful, but the guys there flat out refused the work
• I went to a tire shop in Murphy (A Discount Tire) and they said there was nothing they could do.
• I went to FireStone and they were very helpful on the next steps needed.  I do appreciate their advice but ultimately they did not want to touch it either.
• I called several machine shops close to where I work and nobody would assist.

So, ultimately no progress made.

November 9th

After a bit of research, I determined that I needed a drill press to drill out the old set screw.  I knew my friend Gaba had one, so I scheduled some time to go to his house and work on this issue.

I got some new Titanium bits and some WD40, and headed his way.  The use of the drill press proved to be a good idea.

It was drilling through the old bolt faster than anything we had tried prior.  We kept at it and eventually go the bolt out.  Ultimately was able to finally disconnect the strut from the old lower control arm too.  I did ruin the existing strut threads though.  The last bit used was a 3/8 size bit, and we did wallow it out a little trying to get the remains of the old screw out.

November 12th

I purchased a tap die set from Harbor Freight in hopes of being able to make a 3/8 inch threads.

It turned out that the hole we had was just a little too large for this to work.  Hit the internet again in search of another solution.

While searching for how to repair threads, I came across 2 solutions that seemed like they might work.  The first was to use Loctite Thread repair kit, and the second was to use a Helicoil.  Based on what I could research, I thought I'd go ahead and take a chance on the Helicoil.

I ultimately was still looking for an end result of a 3/8x24 thread.

November 13th

According to the instructions that came with the Helicoil, I needed to drill the hole out with a 25/64 bit.  I can't imagine anyone had one, but that seemed awfully close to a 3/8 (which would be 24/64).  I figured that the hole probably was wallowed out to what would be 25/64 already so I started to tap it using the tap provided in the Helicoil kit.

The tap definitely left some nice deep grooves in the strut.  This looked like good progress to me.

I went ahead an put the Helicoil into the strut.  In my first try, I pushed it through just a little too far.  I tried to trim it - but my wire cutters were no match for the coil.  I ended up pulling it out instead.

I tried it a second time, this time I added a little red Loctite to the threads.  I carefully made sure I didn't go too deep this time as well.  The end result looks like it is a winner!

That's all the progress made so far.  I did test the 3/8 x 24 bolt that I had purchased, and it looks like this will work out perfectly.

At this point I'm feeling confident I can start putting it all back together again.  I just need to find some daylight to get working on it.

November 14th

Not much progress today.  I really wanted to get the strut back into the car, but I ran into a couple of issues.  There is a cover on the coil that I had to remove when I worked on getting the stripped screw out.  I figured I'd install it back in, and quickly realized that a hex head bolt would interfere with the plastic trim piece.

I did manage to break the trim piece up enough to allow the bolt to be used.  It doesn't look pretty - but I'll be honest - who cares at this point. I'm just trying to get the car back onto the road.

 On a side note, I was putting all the parts in the garage spot that my wife would normally be using.  I did clear out all the parts, at least enough to allow my wife to park her van in the garage again.

November 18

Got some time to finally get it all put back together.  I started by putting the lower control arm back in place.  The sway bar link was a little tough to get in (since it is a hex design, had to turn it a little to make it into the hex hole), but otherwise it went in smoothly.

Once that was in place - it was finally time to get the strut back into the car.  Loosely attached the 3 nuts on top, and then had to put a jack under the control are to get it high enough to attach to the strut.  I put a little bit of blue loctite on the new bolt and put it in.  It looks beautiful (to me).

I lowered the control are down.  The strut held in perfectly - as expected.

I added the spindle back in.

And the thrust arm:

Buttoned it all up.  Torqued down all the bolts carefully.  Put the air line back on the strut and tightened it up.

Plugged in the ABS sensor, and the Strut sensor.  Then put the brake caliper back on.  It looked like it was all ready to go.

So I reconnected the battery and let it run.  Much to my disappointment - the strut did not extend out as I expected it to.

I did get the wheel back on - and much to the car's protesting that it was too low - I did move it forward a few feet so I could more easily park my wife's van in the garage.

In retrospect - I should not have disconnected the battery.  The instrument cluster lit up with all kinds of error messages (ABS, ESP, Airmatic). To boot, the radio was dead - screen didn't bother to turn on.

I let it run a few minutes, but the strut never did extend to pick the car up.  I can hear the compressor running.  Figured I'd call it a day for now.

November 19 

Figured I'd start the car again and see if I could clear the error codes.  I have the driver's side held up a little with the stock jack - just so the car's nose isn't totally on the ground.

Today, when I started it up, I figured I'd try turning the wheel all the way to the left, then all the way to the right in hopes it would remove the error codes, but no such luck for me.  I did re sync the sunroof and windows though.

The strut is still not filling up with air - I really need to test for leaks but I didn't have time today to do it.  On the good news side - the Radio did start back up today - so maybe it just needed a little time powered back up before it would do anything.

For now - I'll leave images of my error messages and Hellaflush looking car:

Starting to wonder if I broke the strut while doing all this work on it.  I'll test for leaks as soon as I can - I'm really hoping it is just an issue with the air line connector.

November 22

I'm coming to grips with the fact I may have ruined the strut after all.  My neighborhood mechanic seems to have let all the air out of the strut by mistake.  He did it by unscrewing the valve as he removed it.  In the picture below you can see the part were the Teflon tape is seen, that part was unscrewed.  I was checking for leaks in the image below - but you can see this Arnott strut is not topped off in resin like most other struts are.  

I say this to say I'm giving up on this strut.  I went ahead and purchased a pair from eBay.  It is Chinese product - but to be honest I really just want to get the car running again.

November 28

Struts finally arrived.  They look nice - at least nicer than what I expected.

The only thing to note is the set does not have the set screws.  I contacted the seller and they indicated that it comes that way.  There are no screws they can sell me and to re-use the old ones.

I also contacted Arnott - since after all it was their screw that ultimately put me in this mess.  They indicated they did not sell the screws alone and only would send them to me for warranty work.  This is not a strut I purchased - but just a strut that was already on the car - so in other words I was out of luck.

December 2

Finally get around to swapping the struts out.  Was praying this would be the fix I needed.  I used my main jack to just lift the driver's side of the car.  I disconnected the negative terminal from the battery and then removed the front driver's side whee.  Unbolted the two bolts holding the old Arnott strut in place on the lower control arm, the 3 bolts on top of the strut and disconnected the air line to the strut.  It came out very easily.

Last shot of the old strut in place.  Note how the covering it not seated on the lower bearing....

Anyways - I got the new strut in and loosely attached the 3 top screws.  The new strut was a lot longer than this collapsed Arnott strut I removed.  

I needed more clearance.  I figured the anti roll bar may be the main culprit in not allowing the lower control arm to drop any further.  So I lifted the passenger side of the car with the stock jack.  That jack is sketchy as they come, so I used a jack to rest the actual weight of the car on it instead, but the stock jack was still being used to lift.

That still wasn't enough. I had to recruit my wife a for a few minutes.  I put my breaker bar between the frame and the sway bar and pushed down with my weight while my wife positioned the strut on the lower control arm.  This seated it into place (finally).

I ended up reusing the one set screw I had in the front side of the strut (pictured above).  I rerouted and reconnected the ABS and Strut connections.

It was all looking good. 

I know I'm missing one of the set screws below - but this would be good enough for right now.  I put the wheel back on and torqued it down.  I removed the jack stand and jack from the passenger side.  Then dropped the driver side of the car just to the point where the wheel touched the ground in a solid way.  I tightened up the 3 top screws and reconnected the air line to the strut.

Reconnected the battery, it was the moment of truth. I started the car and set a 4 minute timer.  I told the car to get into the high position.   While that was going on - I kept testing for leaks and saw no bubbles show up at the new strut connection.

 To my joy, the car actually lifted itself off the jack.  I was able to slide it out without first lowering it.  YAY!!!!!!!

I moved the jack out of the way and sat in the driver's seat.  The car had all kinds of error messages on the screen, but the one on the Command screen told me the voltage was low and to start the car.  I was like - "what the heck?".  I got the multi meter and the battery was measuring 8.5V. 

I took the battery out of the car.  It had a Premium Duralast battery and my tester said it was good, but drained.  So I took it to AutoZone and had them charge it back up.  I put it back in the car and did the following test:

Battery at rest (car off): 12.5V

Battery with Load (car in on position but engine off): 12.3V

Engine on: 12.1V

This is not good.

It took it for a short drive (if felt super smooth by the way) and upon the return to the driveway it was showing 11.9V to the battery.  So I am concluding that the battery drained and caused the alternator to burn out.  I guess it's my mistake for not running the engine more - but couldn't let it run too much anyways due to the compressor running all the time while the bad strut was installed.  

On the bright side - the only error message I saw on the display was the old TPMS error message - which this car has had since I purchased it a year ago.  So no shocker there.  But all the other messages (ABS, SRS, ESP, et al...) disappeared.

December 5

I think I'll go ahead and close this post here.  The car has been sitting for a couple of days and it has not dropped at all.  It is sitting beautifully.  I now have to deal with a bad alternator - but I'll go ahead and document that on a new post.

I did buy some 10X1 mm screws on eBay that arrived today.  They are not set screws - but they should be the correct size/pitch tread and should do the job of being the second screw needed to secure the strut to the lower control arm.