When we did the same exercise with the bolts lubed the bolts would require less torque before failing. I believe this is because the international compound (lube) causes the clamping force to transfer to the bolt a lot more than if it were dry. I think this is why manufacturer's want lube to be used on their engine fasteners because they can calculate the clamping force that will be transferred. So basically you should always use the lube the manufacturer calls for and be sure it's the correct one.
On another note when we did the lubed exercise we used a higher grade nut for each bolt so that we could make the bolt fail instead of the nut failing first. You can always use a better nut.
On a side note I started taking apart a Volvo marine hydraulic transmission...but there's never anything to do after class.
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| The Jeff bolt-clamp-o-meter X1000. It's the latest from BTC engineering. |
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| Volvo HS1a |
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| Input shaft and you can see the bearing right behind it. |
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| Just started by getting the bearing housing off. |
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| Sigh...Volvo. |
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| Just got the bearing housing off for starters and you can see the tapered bearing here. Notice the fastener keeping it in place...it looks awfully familiar. |
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| This is the diagram for the transmission...yikes. |
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| A lot of the fasteners on here were pretty seized and hard to get off. |
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| Valve housing took a dead-blow hammer to get off the bearing rollers. It had a fever and the only prescription was cowbell. |
