The Machinist

This does not represent the final surface finish, as my personal surface grinder is still sitting on my trailer under a tarp. It weighs more than a C63, so I’m hoping the neighbor will take pity with his giant forklift.



Damage bored out of the way.

Bushing ready to shrink in.

Finish ground

Making sure the back side is parallel by regrinding it.

You’ll notice that the wear on this lock plate was extensive enough that not all of it was machined out. This would not affect operation.

Oil port detail

Oil port detail

The Machinist

This bushing is made from steel that is 62HRc, which is the same as the lock pin itself.

These should theoretically outlast the engine.

hachiroku

nice

The Machinist

The surface grinder is under the car cover. The OD grinder is partially visible. The OD grinder is in worse shape than I’d hoped, but it was a bonus anyway. The real score was the surface grinder.

This OD grinder is from prior to 1930, and will be a restoration project.

The surface grinder is right at the transition from overhead belt drive to electric motor. This one got the electric motor option. I will be eventually putting it back on a line shaft.


Speaking of iron on a trailer, here’s 11,000 pounds worth.

Some marked up pictures of an antiquated flat belt drive for one of the machines. This is the arrangement for driving the table past the grinding wheel. (Brown and Sharpe OD grinder)

More of the same. This is for the coolant pump.

A MUCH more modern grinder. Plates in progress. Sideways.

The Machinist

I know this probably won’t mean anything to anyone. But I spent a little time pressure washing the 90-100 years worth of shop grime off the surface grinder and it just keeps getting better (for me).

One of my side hobbies is in old vacuum tube electronics. I have a pair of 60 year old hi-fi stereo power amplifiers in addition to a bunch of good stuff from the 1960’s.



Heatkit Aa-121 at full blast.

Up close. 550 volts on the plates. 50 watts per channel, which for a tube amp is stadium worthy.




Conveniently for me, this machine uses some vacuum tubes. Pictured below is one of the mercury vapor rectifier tubes in the DC power supply for the electromagnetic chuck on the surface grinder. Believe it or not, I can still buy these. Mercury rectifiers are amazingly good looking when they are under load. They flash this bright blue color which is very pretty.

Even if the power supply is a total loss I can still run the grinder with a 220v DC power source for the mag chuck. The machine has a provision for belt drive to a dynamo for this purpose.






Starting to clean up.

This is well before OSHA decided that no one had any common sense. Look at all those safety hazards!!!! I can’t wait to fire it up. This will make some really pretty parts.

BLKROKT

Nice work. Keep up with the interesting stuff even if slightly OT. Beats the regular talk of wheel offsets and bang and pop tunes.

Jasonoff

What speakers?

DRBC43AMG

Slightly OT also... I played in a rock band in late 60's early 70's and my Marshall amp had tubes IMO tubes still give the best sound providing the speakers are also of top quality. The heat it gave off was intense and one certainly didn't want to cover the amp with a blanket or something similar

The Machinist

The heathkits are wired as monoblocks each one to an original Klipsch Forte. So, currently putting out 80-100WPC.

This has proven to be overkill. I am waiting for a pair of Klipsch LaScalas to become available on the east coast for less than the million dollars that everyone seems to think they are worth, then I will throw those into the mix.

I also have a solid state Hafler XL-600 driving a pair of big subs. This is certainly underutilization of this amp, as it is also suited for full range amplification quite well. I just don’t have speakers big enough to load it properly.

The Machinist

The guy who taught me everything I know about tubes also played in a rock band and his tube amp collection was one of the most impressive things I’ve ever seen.

The heat is intense. I can actually heat a decent portion of the house with the stereo if it is working hard enough. The glass envelopes usually get north of 400F. It kills me to put forced air cooling on them though, the noise from the motor comes through on the speakers.

The stuff is somewhat off topic, but for me it all comes back to the Mercedes. None of this would be happening if I hadn’t bought my C63. I aim to make ownership of these cars less of a worry by trying to make the dreaded adjuster failure not so much of an expense.

This type of failure is why Audis are all worthless. No one wants the repair bills.


Who would have thought that old industrial revolution American iron would eventually be making precision parts for the best V8 that ever lived?

go team

Love this man!

a4ncar

You are a GENIUS!!! Reuse the existing plates by over boring the damage and pressing a bushing. This is called thinking out of the box. Love it....

Savage-wp

Very nice. My dad restores old Jukeboxes, so I know all about these tube amplifiers. I have helped him rewire the amps.

The Machinist

Thank you.

Welding works too, but the plates should still be surface ground afterwards. The heat from the weld will warp the plate slightly.

I like this option because the bushings are cheap and readily available. They are also the same hardness of the locking pin, which means that they will last a very long time.

The Machinist

I think rewiring of these old amps end up being a given these days. The copper work hardens from the heat, which makes the wires brittle. Also the caps like to dry out.

The old carbon comp resistors like to drift.

At least the components are cheap.

Probably the scariest thing about these amps is the B+ voltage. It’s enough to knock you dead.

Phil1305

nice excited to see the test results, if these work out I can see you being the go to for fixing adjusters instead of replacing. I know ill be in for a set in the future.

Savage-wp

Yes, all the wiring is replaced. The old wiring is pretty useless.
All parts are readily available in the States. We have to import all the tubes we need into SA.

The Machinist

I have no reason to expect that they won’t work, but I won’t have proof of it until sometime this spring when I install a set of them in my car.

Another member, Go Team, is manufacturing new plates too. He and I have collaborated on this project quite a bit. He is currently working towards getting me some cores that I can have ready to go when this thing is launched.

Phil1305

thats good, im excited fir that time. I have 32k and mine are starting rattle on start up.

I dont doubt your work but some times real word beats paper or a possible mis calculation.

The Machinist

I certainly wouldn’t expect anyone to take my word for it, I wouldn’t.

There is another member located In Canada who is putting aftermarket cams in his M156 and he has agreed to sell me his OE cams if they are serviceable. When I receive them, I will be getting them Armaloy coated, which I believe will work much the same as DLC, at 1/4th the cost. Once I have those, I’ll be doing the install.

Your adjusters shouldn’t be worn enough to rattle on start at 32k. Not unless oil change intervals had been ignored, and even then I would doubt it.

The less worn the adjusters are though, the easier it will be for me to repair them. And you’d probably never have to touch them again.

Phil1305

PO owner i think did 2 10k oci. I bought it at 21k and it does a little on start up. And I change my oil around 3k since I beat the crap out of my car.

Definitely looking forward to your test/results.

The Machinist

Wow. That’s surprising that they are noisy that soon. Mine has 72k on it and I’m sure they aren’t silent, but they don’t sound like a small block Chevy just yet.

In our research on the failure mode, we discovered that the lock pin is more than 2x as hard as the lock plate itself. So every time it locks and unlocks, the pin cuts a tiny chip out of the edge of the lock bore.

Phil1305

mine is only slight rattle at start up.

R77C

With apologies for bringing up a slightly older thread - my 2014 C63 (35,000 miles) has cam adjuster rattle for a couple of seconds upon warm restart. Cold start it's fine (i guess due to thicker oil), operating temp re-start is fine, but if the car has been sat for 30mins- a couple of hours it will rattle for a second or two.

I've had all 4 adjusters replaced, and Mercedes have now confirmed to me that the locking pin noise is "normal when the camshaft doesn't lock into a set position when the engine is turned off". I'm not sure I believe them haha!

Let's just assume that my fault is what you describe above and the pin is taking small chips out of the lock bore each time, what is the likely long-term effect? I assume the noise would carry on for longer the worse the locking plate becomes? Would it result in a sudden catastrophic failure or will it be a gradual worsening in noise?

Thanks in advance!

The Machinist

Your right, it is not normal. If your car is under warranty still, I would demand replacement again.

Eventually, the wear becomes bad enough that they will start to rattle continuously at a hot idle. At a hot idle, the oil pressure in the system is not high enough to cushion the backlash from the valve springs acting on the slop inside the adjuster.

I haven’t seen it on the M156, but in some cases, the adjusters of similar design in other engines can catastrophically fail causing severe damage.

Unfortunately I am not quite in production for the repair yet, lots to do in the machine shop still. If MB does not stand by their repairs, better quality than OE repair plates can be had at 63motorsports.com


Im sorry it took so long to respond. I get daily email notifications for responses to threads I am subscribed to. I don’t check usually any more often than that.


Edit again: Missd this detail:

They are right that the adjuster might not lock into it’s set position at shut down, but it would re lock as soon as you touched the starter motor and the engine began to turn over.