crown top the ball studs??

[erickmarciano]

I am about to replace the valve seals with the head in place and have few question?
1-if I see a crown  on top the ball studs should I grind it off?
2- is this a known problem on 280sl's ?
3- by grinding the crown should the adjustment change?

thanks
Erick

1971 280sl
1962 VW
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

[Vince Canepa]

If I understand your term "crown", I would say that calls for replacing the ball studs.  In my experience this type of wear makes the correct valve clearance hard to maintain.  I would not grind them.  I think it is just a function of the design of the engine.  Most show significant wear after 100,000 miles.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[ja17]

Hello Erick and Vince,
Well the problem is not what to replace but where to stop? If you install new ball studs what about the worn sockets in the rocker arm? If you replace the rocker arms with new, then what about the slight wear on the camshaft against the new rocker arms? Well may as well replace the camshaft and cam bearings also? Two thousand dollars latter........

My advice is save your money and new parts for the head reconditioning or engine rebuild down the road if possible. During these kinds of major repairs you will be trying to illiminate as much wear as possible and replacing a lot of parts with new makes more sense.

 The crown is wear and is not symetrical so adjustments on a crowned ball stud may not be accurate or lasting. However doing a flat top "grind" on the ball studs will remove the crown and enable an accurate and lasting valve adjustment.




Joe Alexander
Blacklick, Ohio