Repair-It

FSM (WIS) says to remove the fuse box. Well I had the right idea but that's ridiculous. I think I can get it without doing that. I may need to get a longer wrench if I can't get the nut started but I think I can manage.

That was much ado about nothing. You can actually reach through the strut hole and start bolt. I didn't have any issues holding the nut in the box wrench. Didn't need to touch the SAM after all of that.

I think I had it assembled in like 45 minutes!
Air line not connected yet.
Then I attacked the SAM. It was time to connect the 21 (twenty one) plugs on the SAM itself, plus another module with 5 plugs and I think one that mates inside of the box itself. It took a while to sort it all out.
Reconnected the battery and started the car. It started but.....airbag malfunction, visit workshop. Oh noes. The SRS module had this code:
And it wouldn't reset. So I tore back into the SAM. I was more familiar with it at this point so it wasn't that bad to pull the module, disconnect the power feed and wiper plug and pull the SAM part way out. And when I did, I immediately saw a lonely 1 wire plug that wasn't connected. I swear I studied that for 20 minutes!! Anyway, plugged it in, put everything back, reconnected battery, SRS light gone. Yay. Phew.

With the scary electrical issue sorted it was time to tackle the passenger side, which promised to be easier than the driver's side.

Step one, remove cabin air box and SBC battery to gain access to the rear UCA nut. Here it is.
Here is the front bolt. Nothing comes apart to get a wrench on this, similar to the front nut on the driver's side.
Here is the top work area.
Then I noticed something. The passenger side is an Arnott reman!! The driver's side is an OEM Bilstein (maybe original?). Who replaces one strut?? Man.
Passenger side. Driver side
I completely removed the strut this time. Which necessitated removing the wheel well liner to disconnect the plug. Here is the wheel well liner removed. Aux oil cooler (it has a dedicated fan on the front of it).
Passenger side caliper wear sensor for some reason.
New arm in but not torqued.
The work went pretty uneventfully. Looks like about 2 hours total based on pictures, to fully R&R.
But of course then there was a problem. Looks like someone stripped half the threads on this Arnott strut and tried to repair by wrapping wire around the threads or something. I pulled out the wire like a spring. Very strange.
After running around to a bunch of stores and only ending up with the wrong size heli-coil, I ended up just doing what I probably should have in the first place: teflon taped the threads, taking care not to cover the O-ring. I did also buy a small Viton O-ring assortment. That pretty much doubled the time though it was at least all easy.
Anyway I hope it's good. I put the old O-rings in dry which is probably not great. If I have any leaks I will lube them a little and consider replacing them. I will have to redo the tape on the passenger side, assuming I don't have a gross leak from the start. We will see when I put weight on the bags.

Tomorrow is operation wheel bearings.

Did the wheel bearings today. I started by trying to loosen all of the caliper bolts. In order to do that (because I don't have a lift) I had to turn the wheel to the right to access the left caliper bolts and the opposite on the left. I wanted to get them loose before disconnecting the SBC pump (which is required when removing the calipers or else you risk problems if the pump were to pressurize such as when a door is opened, and the caliper was not on the rotor).

They are 21mm bolts. I also had it in my head that the rears are supposedly extremely tight so I was expecting a fight for the front as well. I wasn't disappointed. It required a breaker bar with an extension to get the left front bolts. I think I used my impact for one bolt actually. And a sledge on my ratchet for another. But yeah they were tight. Pretty sure they have a thread locker, too. Maybe I should have heated them up first.

So with the driver's side loose (finally) I turned the wheel and moved to the passenger side. This was a struggle. But wait.

I used the breaker bar with an extension and put all my weight on it. Eventually it started moving but was just fighting each time. I'm like...why isn't this getting easier? I kept at it. Little by little. Until....SNAP. Broke the bolt right in two. Geez, guess it was really stuck!

Moved onto the lower bolt at least. This one may have gotten loose from my impact. I really can't remember. Anyway I went to loosen the lower bolt with my ratchet and it moved and then got really tight. I'm like, wtf, this is fighting me too? That's when I realized what I had done. I had been pushing down the entire time (just like the driver's side) but I should have been pulling up. OMG. I basically tightened the upper bolt until it snapped. What an incredibly amateur move!! I swear, every time I get into a marathon with this car I always make a dumb mistake (trans fluid in engine). Anyway, I called the dealer and he said they are NOT regularly stocked items, but he happened to have 4 on the shelf, probably from an order that someone never picked up. That's lucky. Something like $9 each which I was happy to pay.

Back at home it was time to see what it would take to remove the broken bolt in the caliper bracket. Obviously if it was totally stuck or had ruined the threads, I'd be buying a caliper. List price on a caliper is.....$950. Sweet.

This part I did reasonably well. I put a bunch of heat on it and used a chisel to see if I could get it to turn slightly. I did see it turn but it was very slow and tedious. Then I remembered I still have Adam's Dremel so I got that out and ground a flat in the back of the bolt. Then I heated up the caliper bracket again and simply stuck a screwdriver into the flat and the bolt turned right out!! And the threads looked good, too. Saved! Here is the broken bolt with the flat ground in it. Now that all the unpleasantness was done I could actually start the damn wheel bearing job. It added like 90 pointless minutes to the job. I did hang the caliper up on the upper control arm with a couple bungies.

This part was pretty quick. Pop off rotor. Held onto hub with some kind of Torx. That impacted right off with my Ryobi. Rotor comes off. SUPER heavy. Then pop off the dust cap, loosen the adjustment lock bolt (5mm allen head) and simply unthread the adjuster. Then pull the whole hub right off the spindle.

I put the hub in my vice and grabbed my new seal puller tool. This is pretty much when I stopped taking pics and it was only like 10:15am.

Highlights:
- Remove bearings
- Drive out races. This took a while and multiple resharpenings of my chisels. I did get them out
- Clean out old grease from hub.
- Drive new races in. I used a combo of stuff but mainly my new bearing race installer tool plus the old races depending on what was needed.
- Add some grease to hub
- Pack inner bearing
- Install new seal FLUSH not below flush (it will go below flush which will render the ABS inop according to the forum - the seal is actually the reluctor which is weird). My new bearing installer made this easy as I just picked the biggest size that was bigger than the hub so it would be impossible to over-drive the seal.
- Pack outer bearing.
- Clean spindle and lightly lube
- Slide hub onto spindle.

So that last part. This was an odd fight as well. I got it part way on and then it just stopped. It seemed like it was bound up. I think the inner bearing was bound up on the spindle and I was trying to pull it off with the seal which isn't great. Anyway I think I almost broke the seal but did not. I'm like....does this bearing not fit on here?? I got out my other new inner bearing and tried sliding it onto the spindle. It went and got a little bound up but slid on. It seems like the tolerances are ridiculously tight for a slip fit. It will go on but if you angle it even slightly it binds up and jams. So after some cursing what I ended up doing was using a light touch because it should not need to be forced. If you force it it will bind up. This method worked. The funny thing is, this is pretty much the experience I had with my supercharger bearing. It would only slide on if you guided it just right. Any slight angle and it would jam.

Once I got that figured out the rest was pretty straight forward except...

I reinstalled the rotor so I could have something to grab while adjusting and also to help spin the hub as I set the bearings initially. When I went to adjust the bearing though I was getting all this play. That's when I noticed I was actually pulling the rotor away from the hub. The short bolt is only on one side. So now I'm thinking....wait was this my issue the entire time?? No, the bearings were bad. But I did remove the rotor and attach my magnetic base to the hub to adjust the passenger side. This worked and I set it to the low side of the tolerance (0.01mm which is something around 0.4 thou, or "a tiny bit of needle wiggling").

I did also reinstall the caliper but did not torque the bolts. I am happy to report that the new bolts threaded in just fine so no thread damage from my idiocy.

Also I used up most of a tube of the Mercedes grease so guess what....back to the Mercedes dealer for another tube (about $12). Should have bought two.

The driver's side was the same but with a few notes having learned something already:
- Having anticipated the issue sliding the hub onto the spindle I used a light/finesse touch and it went basically right on. It is shocking though that you can't just shove it onto the spindle. You really have to be gentle or it will bind up and get stuck.
- I used 3 lug bolts to hold the rotor against the hub so I could adjust with the rotor installed. This seemed like a very good idea and worked.

I think this side went faster. Well it definitely did. Way less BS happened.

So after the control arm job, and wheel bearing job (and a rear tire rotation), it was finally time for a road test at like 6:30pm. I was worried about many things:
1) Air suspension issue due to my questionable repair using teflon tape
2) ABS inop due to some issue with the hub seals
3) That my clunk wasn't fixed
4) Maybe an electrical issue because I took the front relay box completely apart (pointlessly)

Well the clouds must have parted and a shaft of sunlight shown down on me because everything went perfectly. Zero issues, everything great, car drives great, rides great, NO CLUNK! What a pleasure. The front end really feels nice. I tried some low speed high lock maneuvers and there is no clunk. This is excellent and made all the pain worth it.

The alignment is probably a little off. The steering is reasonably centered but it may have a toe issue. Didn't seem to track quite right. I have an appt on Sat for this.

I will keep my eye out for any right front suspension leaks from sitting. Shockingly it didn't seem to leak before but it was holding on by a thread because just about as soon as I touched the fitting, I heard the air bag begin to depressurize. I think what I did is probably better than it was before, and it didn't leak before, so....

I've driven the car a few times. The clunk is definitely gone. What a relief.

Went to Tire Pros for my alignment. I waited with the car and it was about 2 hours before I was out of there, which is pretty much what they told me when I booked the appt earlier this week. Of course, I was talking the alignment tech's ear off which most definitely contributed but he seemed to be enjoying the chat. He has an Impala SS and has worked there for 15 years.

I have good news and bad news.

First, here are the results. Here's the car on the machine. They actually have two racks now. This was the newer machine which is portable. Older lift but he prefers it. He scanned the VIN with a wireless barcode reader to load the car. I don't think I've seen that before. Also the wheel sensors clamp on the tires which he said were brand new. He's had them fall off which sucks. Also some cars have a tight tire to wheel well gap making it hard to roll the car (which is necessary). My wheels don't have much of a lip to grab on anyway. From a before perspective:
Front right camber is out of spec. Too much negative camber. A little too much toe in but not bad.
Front left camber is in spec. Toe right on the edge of spec and taken as total toe, just out of spec on the toe-in side. Really not that bad though.
Caster is fine and I am not sure there is a spec. It just lands in a range. Also notice how much caster it has. Typical Mercedes. Actually I think he said older ones have even more.

Rear right camber is good. Close to the negative spec but good. Toe was also fine.
Rear left camber is good. A little less but within range. Toe was a touch off.

After results:
Front camber is not adjustable from the factory. I think I may actually have to grind out the hole for the lower control arm mount on the subframe and then it could be moved inward a bit. He seemed to agree. He said the camber bolts don't do anything, unless you grind the hole elliptical. This makes sense. So this means I will just have worse tire wear on the right front (and actually I did, that was the side that had chewed up inside tread). He also said I should be able to bring the car back if I wanted to do this mod. I may just wait until the next set of tires for that. Not sure I feel like digging into that unless dropping that arm is easy. I probably have to unbolt the shock and anti-roll bar, then I could drop it out of the subframe, grind out the hole and put everything back. Not that hardest thing but since I was under it all week, I'll take a rain check. He did say that as screwed up specs go, this isn't THAT bad but I will definitely notice increased/uneven tire wear. Yeah.

Front toe is adjustable and was adjusted pretty much smack in the middle of the toe-in spec at 0.17 degrees. Spec is 0.06-0.26 which isn't much anyway. I had 0.31 before and honestly I probably could have just skipped the alignment at least until these tires were shot.

Here's the display with front stuff. Rear camber is not adjustable (wtf, thanks Mercedes). Fortunately it was in spec anyway.

Rear toe is adjustable but the adjustment is weird as hell. My Sigma cars have adjustable toe links with a threaded sleeve like you would expect. Not on this car. It has a rear link and you actually loosen the bolts and turn this weird nut and it slides the link inward or outward as needed. Fortunately I had looked this up in WIS just before I got there so I was able to immediately point out that, yes, you adjust it here just so there would be no BS. Anyway, rear total toe was not enough before. It was a bit more toe-in than the front. It was below spec before and now on the high side of the spec at 0.43 degrees (spec is 0.21-0.45).
I would posit that the loaded camber on the right is going to make the car drive straight on a crowned road but pull left a bit on a flat road. It was kind of doing that before and since camber didn't get adjusted, will probably do that after. I don't imagine making some toe tweaks is going to change any of that. I'll drive it more and see what I think. So far it's good enough.

Other interesting things:
I had him start it because I wasn't sure if the air suspension was doing something funny and dropping the front end. But then the heat waves coming off the car were actually scrambling the sensor readings. Crazy.

One small detail is still not right.

It took a pile of evidence in front of me and mulling it over last night (and overnight). Plus I scraped the front end pulling out of Tire Pros which is abnormal. The left front is now sitting too low. And the reason for this is because of the ride height sensor bracket that attaches to the upper control arm. Basically, I took it apart incorrectly and bent them. I treated it like my STS and popped the link off the ball joint but unlike the STS, the bracket simply bolts to the arm. On the STS, the ball stud is bolted and not really meant to be swapped. These brackets on the Mercedes are just sheet product and they have some bends so they didn't take well to prying forces. Basically I need to unbolt the bracket from the arm and try to flatten the bracket so it sits more flush with the bottom of the arm. This will effectively pull the ride height sensor position up, which will tell the car to inflate the bag a little more and should bring the level up a bit. I will also measure the wheel well heights.

But I noticed this even on the alignment rack. As a result it was also pulling the right rear up. That's why I had him start it, because something didn't look right. Well that didn't make a difference and this is why.

I did also notice that it's off enough that especially in Comfort mode, the ride is very strange. When it goes over dips in the road, the car kind of rotates as it bounces a little because presumably the anti-roll bar is being preloaded to one side and not acting evenly. Very odd feeling. So the height is off enough for me to fix this.

This should be pretty easy and I shouldn't have to remove the wheels. Just jack up from the front subframe, remove the single 10mm nut and straighten the bracket. I could remove the other end from the sensor if I really need to work on the bracket on my vice or something but I will try doing it on the car.

Of course I got an alignment at the wrong ride height but my options are: 1) not care because these tires are close to end of life (3 of 4 of them really), or 2) perform the lower control arm mounting hole grinding to enable dialing back the negative camber, and bring it back soon potentially for a free or discounted re-alignment.

#2 is ideal but it depends on my willingness to get back under the car and I need a little break on that. I will at least get the ride height back.

There is ONE other option on the ride height. Using the STAR/Xentry system (which I don't own yet), you can basically reset the ride height. But I'd have to go to the dealer for that and it also means I'd be setting the ride height with tweaked ride height sensor brackets. So if I were to change them or something in the future, the height would get screwed up again. Probably best to straighten them.

Jacked it up. When I removed the linkage, I noticed that both sides had a nut as a spacer. This was not factory. Someone did this to space the sensors down to give it a lower ride height! Now this didn't explain my recent left/right mismatch, that was because I did bend something. But that's pretty funny. I straightened the bracket in my vice and put it back with no nut. I was worried this side would be too low now...
Went on to the passenger side where, again, I found the same thing. Straightened the bracket and reinstalled with no nut, just like the driver's side.
The result very oddly is that the front left is STILL slammed. The passenger front seems to have come up. I wonder if the level sensor is dead or something?? Either that or it somehow popped off....I will have to jack it back up and check.
I will have to investigate with my scan tool. Kind of annoying but I'll get it. Always something.

Another dumb mistake on my part. I don't know why this keeps happening.

I had the level sensor in the wrong hole in the control arm. So dumb.
Anyway that fixed the issue with the low left front. They seem very slightly uneven but almost identical. I will drive this for a while though I think I may find the front end to be a bit high. So I could either put the nut spacers back, or put a very thin spacer (like a small washer) on just the passenger front. It's easy to tweak and I may end up having to reaim the headlights. I test drove it just now and they are noticeably higher.

Crisis averted. However, I may have gotten it aligned with the wrong ride height. Ugh.