I took my calipers off to renew the discs and there was threadlock on the bolts. I know for a fact that the bolts would have been removed a few years ago by a mobile mechanic whom I use now and again, so unless what I saw was residue from the manufacturing process, he must have put threadlock on them. Never once seen him using a torque wrench, so I assumed he must add threadlock as insurance before giving the bolts plenty of welly.

Sorry, only just seen your question - for a torque wrench to operate at the required torque it must be used by holding it at the end of the shaft on the grip, however in some circumstances it is easier to grip the wrench closer to the head, (particularly when using thw wrench in a confined space or up a ladder) this produces a lower torque when the wrench operates - if you don't believe me try it on a torque wrench calibration unit.

Incidentally, if you have access to a calibration unit it's worth checking your wrench at both ends and the mid point of the scale, they can go out of calibration, particularly if they are not reset to zero when you've finished using them.

Yes I'm aware of the calibration procedure-but can you explain why holding a torque wrench closer to the axis of the fastener that you are torquing will result in a lower measured torque being applied to the fastener?

This is the one big reason that angle-tightening was introduced with redesigned cylinder head bolts/studs to remove the need for re-torqeuing and to improve the accuracy of the torque setting.

Quite. Tightening to a fixed torque value intuitively appears to give a more accurate clamping force until one realises that most of the torque is simply overcoming friction between the male and female threads. If you tighten two fasteners to 100lbf.ft on the wrench, the actual clamping force might differ markedlydue to the tolerences between the male and female threads.

Edited by unthrottled on 21/09/2012 at 22:29

On the Suzi, the gaskets will settle a little, but after the initial retorque from new they're unlikely to squash further, and the torque setting is only 25ft-lb on 14mm nuts & studs.

I believe the loosening is largely due to the one-piece head casting above 3 separate barrels without through-studs to the crankcase ... this allows the barrels to vibrate slightly relative to the head, and I reckon this vibration and slight fretting loosens some of the nuts.

Some aircooled Suzi triple owners cut the 1-piece head into 3 seperate heads (one for each barrel) for easier maintenance -- i.e. you can service an individual cylinder without having to replace all 3 head gaskets -- and this also stops the retorquing cycle!

Edited by craig-pd130 on 22/09/2012 at 21:49