Pagoda SL Group
W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: dnadanny1 on December 15, 2019, 15:17:13
-
Hi there.
How can I accurately decide whether valve rocker arm and pinball adjuster are wore out and need to be replaced?
Is there any standard specification or tools needed for such measurement?
Thanks,
Danny Cho
-
Danny: I just visually inspected mine. If the ball shows a distinct crown on top, it is time to replace. Replace both parts, rocker arm and ball stud. I will post a picture later today of the parts I replaced next to a new one.
-
The basic shape is a sphere with 12mm diameter
-
If the studs have never been replaced, you will most probably not find a car out there that has perfect 12mm spheres and the question is, what is bad and what is still good. Issue will become the valve adjustment and holding it. Here are a few pictures of a new ball stud next to an old one that I replaced. I hope it will show the "crown" that appears when the ball is worn.. My car has approx. 98, 000 miles.
-
I have ground flat, slightly crowned ball studs, and they work just fine.
-
Hi Danny,
This might not answer your question.
However, I have found the ‘shoe’, between the valve and the rocker to be worn.
On top, by the rocker AS WELL AS underneath by the valve stem riding on the shoe.
Regards
Chris
-
Joe: Did you grind the ball studs while they were installed or did you take them out? Did you use the "old" rocker arms or new ones? I have another head with the ball studs not that bad and would consider grinding them instead of replacing.
-
Mike, it is safer to grind them while off of the head. In this way no grindings go onto the other parts. In fact I use my "KwickWay" valve grinding machine to do a precise job on them one at a time. However in the early days I would grind them on a regular bench grinder. Even new ball adjusters have a "flat" top and are not a perfect sphere. Consider the wear pattern and the rocker movement which wears both the ball and the rocker socket over the years. If the valves were very rarely adjusted then a non-symmetrical wear pattern would develop. When the valves finally get adjusted, the new position of the ball adjusters with sockets is uneven and not matched well. The unevenness and dissimilarities of the new mating surfaces can cause issues with the adjustment and/or noise. Regular valve adjustments keep wear patterns more even and minimal. Replacing the ball adjusters or grinding flat the crowns (only if needed), will allow more accurate adjustments and longer lasting adjustments. Realize that replacing all worn parts with new parts is best but also most expensive. Installing new ball adjusters with worn rocker arm sockets, may be another issue, and then if you use new rocker arms, then you have new rocker arms riding on an old camshaft. It can become an expensive never-ending cycle of replacing parts. Some new parts may be NLA from time to time, or different "up-dated" versions of parts can create other issues. Re-conditioning parts to conform to factories specifications and "acceptable wear limits" requires a lot of experience and technical information. Making good judgements can allow good results without replacing everything. Good advice from others with more experience can keep your restoration cost from going out-of-sight.
-
Mike,... . Good advice from others with more experience can keep your restoration cost from going out-of-sight.
That's why I asked yo, Joe!
The issues I have experienced with the ball studs are;
a) The lower threaded part will not come out of the head. I have tried everything, long breaker bar, impact wrench etc. They will not move with considerable effort. I have also read that the threads in the aluminum head may be destroyed if you take these out. When leaving the lower part in the head and taking only the upper ball stud part out, I experience another problem:
b) The specified torque to turn these will no longer be there. I have tried a few different remedies and the best one so far is to distort the threads on the ball stud insert somewhat in a vice.
Grinding them while leaving them in the head would help a lot.
-
Just remove the central post and leave the base behind.
do not attempt to grind them in situ.
-
Thank you "Stick"! That will result in the problem I described above. And there is no real good remedy that I have found yet. As the cylinder head is out of the car, I can give it a good cleaning!