I'm going to start replacing these bolts as a matter of course on a cambelt change.
Better safe than... and all that.
Dan@JPS
Gear change **Edited to Engine Mountings**
just seen this thread Scott - been offline for too long!
Exact same thing happened to me... see here...
Big thanks to Robin though for helping me out at the time.
These bolts are extremely stiff to remove and then reinsert when they are set in place at the side of the engine.
I found that when i was replacing the section that these bolts fit into, I had to thoroughly clean out the threads on both the mount and the bolts themselves - something That I doubt could have been done in place bolted onto the side of the engine.
Even on a vice and with a breaker bar, the bolts were closely reaching torque limit when tightening up halfway without being cleaned.
Exact same thing happened to me... see here...
Big thanks to Robin though for helping me out at the time.
These bolts are extremely stiff to remove and then reinsert when they are set in place at the side of the engine.
I found that when i was replacing the section that these bolts fit into, I had to thoroughly clean out the threads on both the mount and the bolts themselves - something That I doubt could have been done in place bolted onto the side of the engine.
Even on a vice and with a breaker bar, the bolts were closely reaching torque limit when tightening up halfway without being cleaned.
Calypso Red S1 111s
I suspect there are a number of factors here.
(1) the original gunk they put on the bolts needs to be cleaned off, otherwise the friction it causes can be confused for torque (of course you replace it with threadlock).
(2) the mount doesn't sit just right when you're putting the bolts in (that's why these days I never take both bolts out at the same time) - this puts some stress on the bolts that has nothing to do with bolt load but feels like torque.
(3) especially if you have removed both bolts, they are quite easy to cross thread - obviously that will feel like the bolt is torqued up long before it is - though I doubt you'll get the bolts wound in all the way cross threaded!!
(4) when you are tightening them up, the load on the thread is equal to a significant part of the engine's weight, as you are effectively jacking the engine up to the mount (or bending the mount down to the engine), so whichever bolt takes the strain will feel tight early on; obviously the final torque results in a preload greater than the weight of the engine, so this shouldn't mean you reach the torque point early, but it will feel odd.
Ross, the part I gave you came off Neil's old engine; it's possible that there was a degree of corrosion on that that would not normally be found because the joint had been stored unmade and in the open air for a year or so.
I use threadlock on the ends of the bolts and copperslip on the shanks - rightly or wrongly!
Cheers,
Robin
(1) the original gunk they put on the bolts needs to be cleaned off, otherwise the friction it causes can be confused for torque (of course you replace it with threadlock).
(2) the mount doesn't sit just right when you're putting the bolts in (that's why these days I never take both bolts out at the same time) - this puts some stress on the bolts that has nothing to do with bolt load but feels like torque.
(3) especially if you have removed both bolts, they are quite easy to cross thread - obviously that will feel like the bolt is torqued up long before it is - though I doubt you'll get the bolts wound in all the way cross threaded!!
(4) when you are tightening them up, the load on the thread is equal to a significant part of the engine's weight, as you are effectively jacking the engine up to the mount (or bending the mount down to the engine), so whichever bolt takes the strain will feel tight early on; obviously the final torque results in a preload greater than the weight of the engine, so this shouldn't mean you reach the torque point early, but it will feel odd.
Ross, the part I gave you came off Neil's old engine; it's possible that there was a degree of corrosion on that that would not normally be found because the joint had been stored unmade and in the open air for a year or so.
I use threadlock on the ends of the bolts and copperslip on the shanks - rightly or wrongly!
Cheers,
Robin
I is in your loomz nibblin ur wirez
#bemoretut
#bemoretut