[W126 Coupe] SEC cam shafts

[A figment of the Imagination]

Very interesting about the right camshaft failing very
frequently.  This is now my second time through this
process.  

I isolated the problem to be due to stripped out
journal screw threads inside the engine/heads.  These
bolts are about 12 inches long making re-tapping the
threads inside the head difficult.

Basically, when the engine turns over, the cams push
up on the journals a bit.  Over time the stress on the
journals will loosen up the bolts, especially if they
are stripped from a previous owner's/mechanic's
carelessness or due to dirt/carbon debris working its
way into the bolt sockets.  

Either way, it allows for play with the camshaft and
this allows the rocker armss to go bad and the cams to
wear fast.  This will also affect how smooth your
engine runs.

I have to re-thread/re-tap two journal bolt sockets
within the head to correct this problem. 
Unfortunately, I don't know where to go to get a tap
that is 12 inches long and at 10 mm 1.5 inch pitch or
something slightly bigger 11 mm 1.5 inch pitch.  I may
have to put a standard bolt of 7/16 and 14 pitch just
to keep camshaft down and tight at 60 newton-meters. 
I think lock-tite or any other glue is a bad idea.

If anyone has any more insight or can offer help, I'd
really appreciate it. 

-figstir


		
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