Frustration with W123 Valve Adjustment! - Page 3 - PeachParts Mercedes-Benz Forum

funola · #31 05-11-2015, 11:58 AM

Quote:

Originally Posted by ROLLGUY

Although I have not done it this way, I can see how easy it would be to pass by the desired spot. I have done so many with the ratchet on the crank bolt, I know just about the amount it takes to get to the next cylinder without getting back on the ground. Also, not all of these cars have an easy way to hook up a remote starter switch. Only the later cars have the junction block on the wheelhouse, the earlier cars do not. Wait, don't you like the sound the ratchet makes when you forget to take it out and start the car?

I have very good control with my (home made) remote starter switch. It is method b from the FSM below. What Mercedes calls the "contact handle" is the remote starter. Maybe the issue is the generic remote starters are not suitable? I have never bought or owned a commercial one and have no idea if they are suitable (or not). You don't want a switch with a snap action as you push- you will not get good control with those. The switch I use is lightly spring loaded good for 7 to 8 amps and works fine for me. The control is good enough I can line up the cam chain sprocket marks after a few tries.

funola · #32 05-11-2015, 12:13 PM

Quote:

Originally Posted by leathermang

As this forum's Inventor in Residence ..... I was secretly anointed a while ago...
I would like to suggest this :
If you put the correct socket on the crank nut....
and use the correct length extension ... I have no test vehicle so you will have to determine this....
and put a ratchet on that assembly... nothing inventive yet....
then attach a broom stick extension on the end of the ratchet handle... so we are now at 90 degrees to the longitudinal center line of the car....
make this long enough to be under whatever hole is available from the top of the engine compartment..... it does not have to be 90 degrees to the ground....
then attach a joint from another broom stick to the end of the first one.... with a loose joint on it...
You now have a way to rotate the Crank Nut while standing up leaning over the fender and working on setting the valves or whatever..... Just by up and down movement of the wooden rod.
Want to get fancy.... put a bicycle handle on the top....
Note.... be sure you have set your ratchet to move the crank in the direction you want it to move... to avoid an unnecessary crawl back under the car.... something well worth avoiding....

and I totally agree with... if one is able.... upgrading to a modern compressor like the Sanden.....

I got a headache reading the rambling. A broomstick on a joint to a ratchet? Maybe that is possible on your 240D but getting just a ratchet and a 27 mm deep socket on the crankshaft nut from above on an 83 300D is nearly impossible with the fan and shroud in place.

ROLLGUY · #33 05-11-2015, 12:19 PM

Quote:

Originally Posted by funola

Maybe that is possible on your 240D but getting just a ratchet and a 27 mm deep socket on the crankshaft nut from above on an 83 300D is nearly impossible with the fan and shroud in place.

I don't agree with this. It is not that it is nearly impossible, it IS impossible. The only way is from underneath. That is just from MY experience, yours may be different.

funola · #34 05-11-2015, 12:32 PM

Quote:

Originally Posted by ROLLGUY

I don't agree with this. It is not that it is nearly impossible, it IS impossible. The only way is from underneath. That is just from MY experience, yours may be different.

yeah if you read what I wrote again I said " from above on an 83 300D is nearly impossible"

I agree from below IS possible. This was like 5 years ago when I tried. I am sure it is possible from above if I forced it, wrecking the fan/ radiator and cutting my arms up in the process.

Simpler=Better · #35 05-11-2015, 12:36 PM

Quote:

Originally Posted by Graham

Once again you were right on the money

x3

moon161 · #36 05-11-2015, 01:08 PM

After a few tries, I learned not to attend every argument that I have an invite too. On the original topic, it seems to me that the threads on the stem of the valve in question were probably stripped when someone with a couple wrenches over-tightened the the jam nut. That may not actually be the case, but that best explains the phenomenon of a nut that moved in rotation, but not translation.

In you efforts to examine or verify the issue, take appropriate care not to drop the valve down the hole. Recently, I someone (member Lucas?) dropped one and got it back, but it was a nail-biter.

My guess is to do anything besides drive as-is, the head comes off. Once that happens, you open up all the 'while you're in there's' and 'is it worth it's'. Minimally, parts would be new HG and valve, set of bolts at your discretion (another controversial topic).

charmalu · #37 05-11-2015, 01:29 PM

WOW!!! Once the dust settles, maybe Packman the OP will come back and
he can get the Valve Nut question answered, or a follow up.

Charlie

Dan Stokes · #38 05-11-2015, 01:41 PM

Notice I've stayed out of this - but I would like to know the resolution.

I don't have power steering and I have plenty of room between the rad and crank pully so I have no horse in this race......

Dan

PackerEdgerton · #39 05-11-2015, 02:06 PM

Wow. This thread sure went sideways.

OK, here's the update:

VSTech: "If you hold the spring and only turn the locknut, does the top nut spin?"
No, if I hold the spring still and only turn the locknut, the top nut does NOT spin.

VSTech: "Hold spring, clockwise turn lower nut until it has a good three threads clearance to the top nut. Visually verify the spacing. Then spin the top nut to meet it. You could simply have a massively out of adjustment valve."

Here's what I did:

1) I turned the lower nut until I was able to see space between the two nuts. When I turned the lower nut, the top nut did NOT turn with the lower nut, it stayed in one place.

2) I then turned the upper nut to meet the lower nut. When I turned the upper nut, the lower nut did not turn, it just stayed where it was until the upper nut met it.

3) Doing 1 and 2 did not affect the spacing between the rocker arm and the cam at all.

Analysis:

I think that the top nut appears to be 'stuck' on the top of the valve...in other words, it seems that the top nut is not moving in relation to the valve itself. In other words, I think that the top nut and the valve itself turns all as one. This explains why the lower nut turns freely, and the top nut 'appears' to screw down to meet the lock nut.

What should I do now? Should I attempt to free the top nut from being stuck to the valve? Is this a reasonable explanation? I'm kinda stuck.

Sincerely,

Packman

Stretch · #40 05-11-2015, 02:15 PM

Quote:

Originally Posted by PackerEdgerton

...
What should I do now? Should I attempt to free the top nut from being stuck to the valve? Is this a reasonable explanation? I'm kinda stuck.

Sincerely,

Packman

I think you should do what was suggested in post #3!

(though it was a long long time ago {your mother should know} )

PackerEdgerton · #41 05-11-2015, 02:21 PM

Quote:

Originally Posted by Stretch

It sounds like the threads are stripped.

Remove the glow plugs (if you haven't already done so - so you can crank the engine over by hand with ease)

Remove the rocker arm pair associated with the offending valve

Remove the follower and lock nuts and hope that the threads on the valve are not stripped.

Usually the threads in the nuts die first because they are cut whilst the threads on the valves are (probably) rolled (and are therefore stronger)

Hi Stretch,

Thanks for your feedback. I understand what you wrote here, but I am unclear on what you are suggesting next...

Removing the follower and lock nuts will allow me to see if the condition of the threads.

Assuming we're dealing with stripped threads:

1) Nut is stripped = replace the nut.
2) Valve is stripped = use a thread die on it? Other suggestions?

Sincerely,

Packman

Shortsguy1 · #42 05-11-2015, 02:25 PM

Is the third valve adjustment wrench supposed to help with the OPs problem? I thought it somehow kept the valve from rotating?

Stretch · #43 05-11-2015, 02:27 PM

Quote:

Originally Posted by PackerEdgerton

Hi Stretch,

Thanks for your feedback. I understand what you wrote here, but I am unclear on what you are suggesting next...

Removing the follower and lock nuts will allow me to see if the condition of the threads.

Assuming we're dealing with stripped threads:

1) Nut is stripped = replace the nut.
2) Valve is stripped = use a thread die on it? Other suggestions?

Sincerely,

Packman

Don't worry about the threads on the valve until you get to see them.

I have a feeling (and a big hope) they will be OK but the cut threads in the nuts will be dead.

What ever you do - do not drop the valve in the cylinder!

Place the piston near the top end of the stroke so if the valve drops it just rests on the piston crown.

Stretch · #44 05-11-2015, 02:30 PM

Quote:

Originally Posted by Shortsguy1

Is the third valve adjustment wrench supposed to help with the OPs problem? I thought it somehow kept the valve from rotating?

He has reported that he is using the third wrench so if the valve is being held tight and the nuts go nowhere I kind of suspect there will be stripped threads (hopefully in the nuts)

Shortsguy1 · #45 05-11-2015, 03:06 PM

Yes, I read that in his first post as well, but this statement seems inconsistent to me..."I think that the top nut appears to be 'stuck' on the top of the valve". So I was wondering if perhaps he was using the third wrench incorrectly. I have never had to use one, so I am not passing judgement. I just felt there was an inconsistent statement that should be evaluated before he took the engine further apart.