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Old 06-12-2019, 01:54 PM   #23 (permalink)
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Originally Posted by IsaacCarlson View Post
Bearing wear? The only bearings that were bad were on the balance shafts. That says something. How would a bit more vibration hurt my remaining bearings, especially with increased oil pressure? I'm calling BS on the "more wear from vibration" theory. Diesels vibrate like crazy. My inline truck motor vibrates enough to shake the mirrors at idle. I'm not worried about the tiny amount of vibration hurting the rav. I can barely feel it and nobody else can even tell it's there.
Wrong kind of vibration. I have a Cummins as well and any vibration you are getting there is due to bad mounts not internals. Those engines all run a harmonic dampener which does the same thing as a balance shaft. A balance shaft counters the harmonic vibration of the crank as 4 cylinder engines or arenít able to equally apply force 360 degrees around the crank thus making them harmonically unbalanced by nature at higher rpms. The larger displacement of a cylinder the more effect that harmonic unbalance will have. Just about every 2.2l 4 cylinder or larger runs a balance shaft. Inline 6 cylinder and above typically donít need one and only need a harmonic dampener. All that said since a balance shaft is just a counter rotating eccentric shaft or a weight and has little to no power drain so I have to call bs that you noticed any fuel economy difference. Now if you performed the removal in a controlled environment where nothing else on the engine was replaced tans even the same oil was reused then I would be more open minded. Also harmonic vibration engine damage is well documented thanks to years of research from racing.
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