When it comes to using a torque wrench to tighten a bolt or nut, the manual states a given range to set it to. The range of tightness seems to vary quite a bit. I believe the wide range is because of the bolt's material strength (it's composition), if there's any lube involved, etc. But what I'm wondering is if I should just go with the middle of the range like I have been, or maybe go with the low end of the range stated in the manual.

 

Depends on the fastener being tightened. For example, cam plate studs I torque on the low end as they strip easy. The rear wheel nut I torque on the highest end. Most regular fasteners, I torque in the middle.

 

think of a bolt as a rubber band. engineers factor in application and then size of the fastener and the rated torque range the mfg says it will support. if too tight, thread failure can happen and if too loose the the connection can fail. this is with new unused fasteners. the manual does not know what you are doing so specifies a range that the mfg say will work with the application. if the fastener is used, it theoretically is stretched and will require more applied torque to achieve a set amount of clamping force. the mfg say do not exceed the upper limit or damage can be done.
as far as lube, nothing to do with it. if you use a lube, you must factor in 10>20% adjustment in torque (reduction) so you do not exceed the highest suggested limit, unless the manual says to use a lube and torque to a set level. the head bolts is an example. some fasteners (increasing in numbers) require a set torque and a certain degree of additional rotation regardless of torque numbers.

 

i torque all bolts down just because i am strange about that, my thinking is if you a little lose on your bolt,( low side of torque spec.)you can always tighten it down latter if the bolts works lose, but if you are to tight you have a strip thread now you have a bigger problem.

 

I would hope following the FSM and using Loctite where specified that would not happen.

The problem with a bolt working loose is it lets the two components bang against each other and the bolt usually snaps.

 

Go to the middle. The range is due torque wrench tolerance which is usually around ±4% of setting.

 

Anywhere in the proper range is fine, there is no reason to overthink it.

 

I dont do alot of wrenching .. mainly for two reasons .. Im lazy and if I have time I want to ride ..so I let the Indy do any real wrenching. But when I do, I just use the "top dead center" setting.
i.e if 10-15 Ill set 12.5

 

From the Factory Service Manual:

 

This has absolutely nothing to do with the original post.