Pagoda SL Group
W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: Tomnistuff on July 14, 2017, 17:46:55
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While assembling the accessory drives on the front of my Metric rebuilt 230SL engine, I discovered that Metric, for whatever reason, left the front stud of the chain tensioner flange protruding from the cylinder head 6.5 mm beyond the nut. That 6.5 mm difference can be seen by comparing the two photos attached.
The photo of the dirty engine is the original stud, photographed prior to shipping to Metric. It actually looks like the stud end has been ground off.
The photo of the clean engine is as it was returned from Metric. I, and I suppose most people, would consider the protrusion normal, if I had noticed the difference at all, and continued to assemble the front end.
I finally discovered the difference/problem after I had installed the thermostat housing with the gasket and adhesive and had installed the bypass hose and was feeling around the hose to make sure that the clamps were not too near the ends of the hose. The stud end was pressing an indentation in the bypass hose and probably eventually would have worn a hole in the hose.
It was almost obscured by other hardware and difficult to see the contact point. I thought of removing the thermostat housing to grind off the stud, but I had no spare gasket so I hand-held a hacksaw blade and spent about 45 minutes removing the protruded stud end like a jailhouse prisoner saws the window bars.
I love the work done by Metric Motors on my engine so I am not complaining. I'm just bringing to your attention the need to compare before and after rebuild photos to identify differences BEFORE you start to install the rebuilt engine and assemble the ancillary hardware. I have been lucky. My failure to do so only cost me a few hours of work.
Notice the beautiful work done by Metric Motors.
Tom Kizer
Levis, Quebec, Canada
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I would assume the original stud was a custom length and when they replaced it with a new stud the length didn't match. Good catch.
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As a general rule, Mercedes does not design studs/bolts to protrude very far past the nut when tightened. Corrosion on the exposed end being a reason and why there are so many bolt and stud lengths on these cars. If it sticks out too far past the nut when tight, it probably isn't correct.
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For this particular stud, if it sticks out more than 3 mm beyond the nut, it interferes with the bypass tube. See the photo taken looking upwards from below the front of the engine.
Tom Kizer