Bonneville America Forums Forums Technical Forums General Tech torque values for cases

hello,

i'm putting my cases back together and the book calls for a different second stage torque value for engines before 326093 (mine being an 02 is before this number) but also has two different stage 2 torque values for silver bolts and bolts with olive green. my bolts look gray. if anyone could clarify i'd appreciate it.

-brin

there actually may be a small spot of a yellowish green on some of the m10 bolts.

how about a pic?

snug

Ive been going back and forth with Brin via email about this and thought I should post here so there is more than just my thoughts...

Heres what I see between Haynes and Triumph manuals

All go to 10Nm for first round.

Haynes (Bolts 1-8)
Green 10MM = 48Nm
Silver 10MM = 40Nm

Triumph (Bolts 1-8)
Green 10MM = 35Nm
Silver 10MM = 40Nm

Bolts 9-19 are the same for all (28Nm)

I would go with the Triumph value as that is the factory manual and what the local shop uses. The Haynes has been known to be a bit off in some respects.

I also think you would be safe by tightening to the Silver spec of 40Nm.

then lets not leave out what my triumph manual says which is 70 degrees for stage 2 on the green bolts.

I don't get the torque stuff being so different in many instances between the haynes and the Triumph one, i was looking at them last night (thanks Z) and there are a few right out of the gates like the yoke bolts and so forth that are a fair bit off, kind of makes a guy go Hmmm?

I have never used a TQ wrench on a motorcycle case in my entire life and have worked on thousands of motorcycles old and new without a single issue.

Whenever your bolting Steel into Aluminum, those Torque values are stated to keep the uninformed and unexperienced from having to learn about Heli-Coils and the application there of. An even amount of engineered force by the fasteners on even an engine case, helps to keep from imparting a misalignment (tweaking) in the bottom casting for the bearing journals. Even the floor mounting bolts for a 6 Ton milling machine are thoroughly checked for a soft foot and a specified Torque application, at least in the Aero-Space machine shops around me. Water pumps, installed correctly, deal with "pipe strain", if the plumbing attached to the pump is not relaxed, the pump usually will experience premature failure. Ultimately, torque values should be followed by all, because a failure of a component on a motorcycle can be catastrophic, as we all should know..

Suppose I should specify outer case.

I am talking about outboard cases as well, I am up for debate, as long as it doesn't conflict with my schedule and I'm trying to listen/take notes to this Liberal old Bat Professor s lecture in class as we converse, as well. Let the multi tasking begin.

I am not advocating not using TQ values just that I have never done so except on internal engine parts. I have been working on cars and bikes for 35 yrs give or take and have never seen an ill effect from it. I don't strip or seize any of the fasteners and I get average or better life from the engines I have done.

Good on you, Ian, I was taught different, and I must admit, I know my way around a Frame 7 Turbine or a paper machine better than I do a 350 Chevy. GTG to my next class. Peace

I have worked on paper machines, I used to work for a paper machine rebuilder and there are many parts on those machines that are very sensitive to TQ and would always use the correct values and a well calibrated TQ wrench or dial indicator for end play just as I would on a crankshaft in an engine. I have no experience with turbines so I can't speak to those at all.

matt says torque them to 40. he didnt ask green or silver.

as far as torque values go, i would think its pretty important when concerning the main bearings. i could see it not being as big a deal dealing with pre computer machines but you might as well take advantage of the new engineering, and torque to what's been tested. but what the hell do i know this is my first motor.

40 nm , ft lbs, or in lbs? I think as a novice you should use the proper TQ to avoid over tightening for sure.

When I was just a pup, my Uncle was teaching me how to rebuild small block chevy's. Big limb on a tree out front kinds of tech stuff. He showed me to bolt the heads down by giving them enough torque to make them scream a little, then give it a 1/4 turn more. Worked great, except once! SNAP! (Oh crap, take it all apart again...)

what's a ft lbs?

Torque on these machines is pretty important only because some of these metric bolts as cheap as hell. I'm pretty guilty of not using one and paying for it. Always error on the side of caution, especially if inexperienced. However, if you're a fine tuned machine like the Dog, you're good to go.