Originally Posted by
dinasrt
Again, great pic.'s, but still doesn't explain how the hollow bolt has anything to do with that. And again, is Rob wrong about this? If you are right, then Rob got it wrong; Right? See his explanation of the SC pulley bolt @ Needswings.com.
Either he is right or Rudy and myself are right.
When you have gears rotating at high speed an aerosol of the oil will be formed at the same time the air in the SC gear housing will expand with heat. You do not want that aerosol mixing with the hot air escaping through the bearings and seals at the front of the SC as this will soon deplete the oil. You basically just want the expanded air to escape and the minimum of oil.
The photo shows the hole in the shaft from both ends, with a hole in the bolt why wouldn’t the expanded air and the cooler air later pass through the whole to bring the air pressure inside the gearbox back to the ambient air pressure?
I made the wrong assumption way back and I got this reply from Rudy. Ironically you replied to Rudy’s post immediately after his post and did not disagree then.
CLiCK