The nuts. But trying to have all springs removed... leaving the valves in there hanging with temporary nuts alone..rotating the crank to do the next cylinder...you see it is a funny task.
Just get a set of springs and change them one at a time while doing the seal change. ...and a couple of adjuster nuts in case one has bad threads.
Observe the proper orientation of the springs.
https://www.pelicanparts.com/catalog/SuperCat/3202/MBZ_3202_ENGCYL_pg2.htm#item9

I’m up for it, but I’d like to make sure it’s absolutely necessary. I’ll be going from $6 to another 60 or 70 bucks in parts.

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1981 240D 4sp manual. Ivory White.

Get the rockers out of the way and complete one seal at a time. The nuts on the other springs will keep the valves in place and so will the valve spring keepers.

I'm trying to emphasize ONE at a time. Any other way is going to create problems putting everything thing back in its original position.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

And your thoughts on replacing the springs as well?
Think it’s necessary?

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1981 240D 4sp manual. Ivory White.

Not sure I understand the question. When you remove the old Valvestem Seal there is going to be nothing keep the Valve from dropping.

Depending on the condition of your old Valvestem Seals there may be no gripping at all on the Valvestem to keep the valve from falling.

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84 300D, 82 Volvo 244Gl Diesel

Sorry, this was in relation to removing valve springs to measure against one another. Having just removed the rocker arms, I have a better understanding of how this all works. Taking my time though (no where to go!).


QUOTE=Diesel911;4031339]Not sure I understand the question. When you remove the old Valvestem Seal there is going to be nothing keep the Valve from dropping.

Depending on the condition of your old Valvestem Seals there may be no gripping at all on the Valvestem to keep the valve from falling.[/QUOTE]

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1981 240D 4sp manual. Ivory White.

You can check your valve springs:

https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/Engine/615/05-260.pdf

as far as the test tool goes you can cobble up something from a bathroom scale and a measuring tape

If your doing the TDC method instead of air, when #1 is TDC #4 will be also (Yes, they're both TDC with air too). You could remove all of those springs and the piston will keep the valve from falling. Just confirm with the first valve you do that it won't fall by lowering it until you feel it hit the piston. This would allow you to compare heights or you could just measure and record each spring.

Would I blanket replace all of the springs? No only if I saw a problem with two or more. One bad, then just that one. My guess is that you won't find any problem with them.

Go slowly, be methodical, double check each part of your work and you will be fine.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

There is a nice MB tool for pressing down the seals:

Attached Thumbnails

 

[/QUOTE]

To get the valve springs off the valve is going to go down.

People have mentioned the Valve Spring Tester. As mentioned it has a scale on the bottom and you insert the Valve Spring and there is an arm and plunger setup that pushes down on the valve spring and compresses it X amount and at that point you are supposed to have a reading from the scale and that amount has to be within specs.

And there of course is the free length of the spring.

On mine I just changes the valvestem seals and reused the untested valve springs. Been driving after that about 10 years with no obvious issues.

On these Mercedes they differ from most engines in that when you adjust the Nuts to adjust the valves it changes the tension on the valve spring a little

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84 300D, 82 Volvo 244Gl Diesel

I’ve decided to measure their free length with calipers and save the values.
If I find any obvious discrepancies I’ll replace. Otherwise, I’ll add them to the “if I ever need to pull the head” list.

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1981 240D 4sp manual. Ivory White.

Shern ;

I wasn't thinking of your job when I mentioned measuring the springs, sorry about that ~ I usually have a cylinder off & on the bench, may bad there .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

No problem Nate!

Meanwhile, I have the first cylinder done. I'm a little shaky regarding how far to push these seals down... I was able to do the first two with a firm press of my fingers.


I also nearly made a major mistake confusing cylinder number with firing order.
I had cylinder one at TDC and then began loosening nuts on cylinder three (firing order four). Fortunately, I was dubious enough and kept needle-nose pliers on the valve the entire time. Once I realized it couldn't reach the cylinder, I put a retaining nut back on.

Concurrently, I have a brisket smoking. I imagine both will be done by the time I am.

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1981 240D 4sp manual. Ivory White.

Okay, I have all the new seals in, and the valves back in place. What remains are the rocker arms.

The good- no side to side wiggle on any of the valves so I guess my guides are okay.

The bad- I found a metal shaving trapped between two of the adjustment nuts.I looks like a broken off thread. I checked the threads of everything I could but found no sign of anything missing.

There were some tiny metal shavings on one of the valve threads. When I was installing the lock nut, as I tightened, I could see them moving around to the channel. I was able to wipe the gunk out, but it's made me very nervous.

As far as I can tell, nothing is stripped. I took everything apart again to get a look at the threads (fine) and hit them with brake cleaner to be safe. As far as I can tell, any of these particles would be trapped in the channel between the adjustment nuts

I've wiped the surface of the head to make sure it was free of debris, but beyond that, I'm not sure what my best course of action is.

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1981 240D 4sp manual. Ivory White.

If you took it apart, cleaned it up and the threads look good, you have done all that you can. At this point I'd put it together and expect no problems from the shavings.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer