Here's a link:

http://www.import-car.com/ic/ic40024.htm

__________________
Regards

Warren

Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor

Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL

ENTER > = (HP RPN)

Not part of the in-crowd since 1952.

ctaylor738, if M-B had used an 11 mm. longer head bolt, they could have engaged all the threads in the block and reduced the risk of stripping, n'est-ce pas?

I'm a noob, so if I'm wrong about this, please correct me.

retro

I'm not sure more that contact with more threads would help the situation. I've always wondered why the threads go bad in the first place.

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Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

My guess is galvanic corrosion caused by dissimilar metals (steel bolts and aluminum block). Mercedes tried to address this issue by changing the head bolt coating from phosphate to nickel in November of 1982. This change had to help but it is not 100% effective. I wonder if an additional anti-galvanic spray barrier coating on the bolts at the time of installation would have helped. Also, Mercedes could have done a better job by helicoiling the block from the start. Mark

We had a similar problem with housing bolts on Submersable Aluminum Pump bodies that were installed in a 200 ft deep shaft to control shaft flooding and the maker switched to a similar treatment and 70% of the probolems went away.

The problem was getting the site techs to take the time to collect and toss all the old bolts during a refit.