Valve Adjustment Problem

[enochbell]

Ben,

Theoretically yes, you could adjust the height so far as to expose the locking threads on the stud and, effectively, loosen the stud from the head.  But I don't think there should be any worry about actually running out of thread and risking pulling the stud out of the head.  There is at least a cm of travel in the stud with the threads properly seated, and if you needed to go to the max height it could only be because there is so much wear in the valve, rocker, cap, cam...you would be into a new head way before you ran out of adjustment.  On the other hand, I think if you were to run the stud in and out of the head too many times it would lose some of the friction that keeps it in place, it would become too easy to turn, and then you would need to replace it.

And that is WAY too much information about ball studs, I think.

g

'64 230sl, fully sorted out...ooops, spoke too soon

[Ricardo]

Hey Greg
Not too much info at all!
I'm wondering if when the threads start to weep oil through to the spark plug, if this is an indication of worn adjuster threads and a likelyhood of changing valve lash?, or are the threads in the base at fault for oil seepage?...... Joe?

[enochbell]

Ricardo,

I don't think it is possible to leak, I believe the threads are cut in a blind hole in the head.

g

'64 230sl, fully sorted out...ooops, spoke too soon

[ja17]

Hello Recardo,
Not really, the weeping is caused when oil leaks past the threads in the ball stud base threads in the head. Consequently, these threads are open to the area above the spark plugs. This is frequently mistaken for a valve cover gasket leak. You can actually feel the bottom of the ball stud base in the recess above the spark plug if you feel for it. I am not sure what actually causes the ball stud adjusters to become too loose, but it is unusual.
The scary part is that the base of the ball studs on the other side are open to the exhaust ports in the head. So if these are leaking oil is mysteriously burned off in the exhaust.


Joe Alexander
Blacklick, Ohio

[Raymond]

Joe,
  I have a bit of a leak over a plug that seems to be coming from the bottom of the ball stud.  What's the best fix? Should I replace the ball stud?  There aren't any other problems with valves or adjustments.

Ray
'68 280SL 4-spd Coupe

[113gray]

To update my "valve adjustment problem", my project is finished & my Pagoda (143,000 mi) original engine idles, runs smoothly & w/ good power. To share a few things learned in addition to the great help the list provided: 1) The Hazet 14mm valve wrench you recommended is a huge help. 2)That said, I found that measuring lash w/o temporarily removing the wrench could result in inaccurate readings. 3) Also, the rocker arm springs need to be perfectly installed for correct readings. 4) I have not learned to use my big screwdriver very well to depress valve springs for rocker arm removal. I wish for the "special tool" which appears not only simple but very effective as illustrated in the BBB. The job got done, but it was not pretty! 5) The BBB identifies the position of the intake valves w/ an "E", exhaust w/ "A". Perfectly clear if one knows "ein" & "aus", but it confused me -easily done- until I marked the intakes by the adjacent injectors. 6) Understanding that there are 2 sets of threads on the ball studs slightly different from each other as a locking mechanism helps to comprehend the correct "feel" for turning them. 7) My valve cover was not as easy to remove as I had anticipated. Between the FI lines in front & hood latch in back, it was very tight indeed.
All's well now, however. I thank you all for the wonderful responses to my call for help.     -JP- 230 SL 5 Spd

[al_lieffring]

quote:Originally posted by 113gray

 My valve cover was not as easy to remove as I had anticipated. Between the FI lines in front & hood latch in back, it was very tight indeed.      -JP- 230 SL 5 Spd

Sometimes if the rubber trans. mount is flattened out it can be hard to get the zundfolge off/on to adjust the valves. Putting a floor jack under the bellhousing and taking the pressure off the rear mount will give you the extra clearanceyou need to get it past the hood latch.

Al

113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket

[113gray]

Al, That's a good tip about jacking the bell housing for more clearance in removing the valve cover. Thanks,     -JP-

[al_lieffring]

quote:Originally posted by 113gray

Al, That's a good tip about jacking the bell housing for more clearance in removing the valve cover. Thanks,     -JP-

Because it's been 20 years since I have worked at a Benz shop I't takes me a while to recall some of the clever tricks that we came up with to work on these cars. When removing rocker arms, even though I have the spring compressor that is shown in the BBB I usually just used an Allen wrench with the short end inserted into the lube hole for the ball stud and levered it up and off to the side.

Al



113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket

[merrill]

113 Gray
to retorque the head does one use an allen socket?  if so what is the size?

thanks
matt

[113gray]

Originally posted by merrill

113 Gray
to retorque the head does one use an allen socket?  if so what is the size?

Matt, Yes, I use a 10mm allen socket, 1/2" drive. It is 4 1/2" long, which is a big help in providing clearance.          -JP-

[merrill]

113gray,
sorry, another question for you, I am getting all the parts together to get this car back on the road.
I have read that it is best to re torque the head after the car has been run to normal operating temp.

would it be bad to torque the head cold and then do the valves ?
lord only know when the last of the parts I need come in and I want to get the car back on the road rather than keep messing with it.

thanks in advance
matt

[113gray]

"I have read that it is best to re torque the head after the car has been run to normal operating temp.

would it be bad to torque the head cold and then do the valves ?"

Matt, IMHO, it's probably a waste of time trying to adjust valves accurately until until the head bolts have been tightened w/ engine hot. I don't know what engine work you're doing, but if the head is off for instance, & you can't run it to get it hot, the procedure is quite a bit different. Briefly, in reassembly work, the head bolts are each tightened both sequentially & also in stages, I recall 4 stages ?, of specified increasing torques. Then valve clearances are then set cold & after the engine is running and has been a few miles ,maybe 100-200, the head bolts are retorqued "hot". The next morning, on a cold engine, the valve clearances are then checked & set as required. I am certainly not an expert here & there are many that are on our list. I hope they will chip in. If you're doing any thing very major, you're very courageous to do it w/o a shop manual/BBB unless considerably experienced. Good luck,  -JP-

[ja17]

quote:Originally posted by Raymond

Joe,
  I have a bit of a leak over a plug that seems to be coming from the bottom of the ball stud.  What's the best fix? Should I replace the ball stud?  There aren't any other problems with valves or adjustments.

Ray
'68 280SL 4-spd Coupe

Hello Ray,
The base for the ball stud is threaded and screws into the head. this threaded hole is open to the recess above the spark plugs. You can feel it with your finger right above the spark plug. This seepage will show up as a wet or darkened spot around the spark plugs. It is often mistaken for a valve cover leak.

To cure the problem the rocker arm is removed the ball stud and its base is unscrewed. (You will need a long 1/2" breaker bar and a 24mm deep socket). The threads are cleaned and sealed with gasket shellac, permatex #2, locktite or such. (I recommend not using silicone sealers). Never use anti-seize on the bases or they may accidentally begin to turn during a normal valve adjustment. The base MUST be correctly torqued back into  place. The rocker arm is then re-installed and valve lash adjusted.

There is a danger as Dan Caron has pointed out previously. Occasionally the threaded base becomes seized in the aluminum cylinder head and when attempting removal, the threads become gaulded and damaged. An afternoons work turns into days of torture as a result.

Some other suggestions are that if you attempt the job try to remove the ball stud bases while the engine is still warm. You may wish to seal only the leakers since they are "pre-lubed". The good dry ones are more likely to seize and gauld.

The 230SL engines and possibly early 250SLs had 14mm ball stud adjusters  and the later 250SLs and all the 280SLs had 17mm ball stud adjusters. The bases on the two types are different but are both 24mm wrench size.

Joe Alexander
Blacklick, Ohio