torque of exhaust flange bolts

:o I read the specs wrong in the shop manual. I torqued the flange to the cylinder heads at 40-50 ft ponds. I now know that the correct torque was in inch pounds 60-80. It translates to 5-6.7 ft pounds. My question is do I need to loosen these bolts and re torque them at the correct torque? They are really really tight,too tight. Or will I be ok since the bolts did not snap. I don't really want to make a mess out of things ,like snap the bolts.

[Mike]

The only reason we know what happens is from all the bolts we've overtightened!!! :( Yes you should loosen and re-torque the nuts. If not done there is a very great risk of th studs breaking and that can get messy. You will also need to replace the exhaust gaskets. The torque spec's based upon new/unused gaskets to achieve the proper crush. Last be sure to put some type of lubricant on the nuts so that the correct torque can be achieved. Motor oil works fine as does lubriplate. Both will smoke for a bit when the bike is first started but will burn off pretty quick and once dry the nuts will tend to stay put

I got all 4 bolts loose. It really helped to take off the heat shield on the front pipe. I had started to strip the upper front nut. I was able to get it off after removing the heat shield. It is a pretty tight location. I am glad everything loosened up. I had a little loctite on them. So then I need to put a little oil on the studs to get the correct torque and no loctite is that correct?

[Mike]

Correct, no locktight. The locktight will loosen when hot, defeating it's purpose (the temp depends on type used; I.E. red, blue, green but the exh will get hot enough to release pretty much all of them) and may pull the stud when cold. You may want to retorque the nuts after the bike has been warmed up but only do this once.
Mike

[David Jackson]

Hi Mike;

I certainly do not know as much about these things as you do; not by a long shot!

I carried an inch pound torque wrench (1/4" drive) and various sockets and extensions around with me for about a week last time I put a different exhaust system on my bike and I found that the torque did not stay at 60 to 80 inch pounds until I had retorqued the nuts about five times. I put Siloo Anti Sieze on the exhaust studs before I put the nuts on and I never tightened them over the recommended amount but I did not trust just doing it once as I had a pair come loose once, drop one of the headers a bit, leak, break a bracket, and all sorts of no-goodness.

I noticed you your response above you say don't retorque more than once.

Am I mistaken in my approach?

Regards;

David Jackson

[Mike]

Your fine. H-D says to only retorque one time and I was using their recommendation to be politically correct. They claim leaving the bolts on the loose side allows the exh. system to "float", they also claim the bolts will not loosen even though not tight. This seems to work on stock exh/bikes that do not have a lot of movement (very good mounting). Aftermarket typ. are not as rigidly mounted and so have more movement due to increased vibration (flexing mounts or not enough mounting points) and so require the flange nuts to be run tighter and checked more often. Sounds like you have it under control and can enjoy riding!!!!
Thanks, Mike