Exhaust Bolts
Thread Starter
|
Advanced
Joined: Jul 2015
Posts: 94
Likes: 9
From: UK
Exhaust Bolts
I have a 2008 Fat bob running Vance and Hines 2 into 1 pipes. I recently noticed a rattling noise and discovered it seems to be the 2 bolts holding the front pipe into the engine have worked their way loose causing the flange (is that what its called?) to vibrate about.
The nuts are in a pretty rusty state so i've been too worried to attempt tightening them back up.
Any reccomendations on what to do at this stage? Anything i can try?
Please note im a pretty clueless mechanically but i am eager to learn (Not at the cost of an engine rebuild though! :P )
The nuts are in a pretty rusty state so i've been too worried to attempt tightening them back up.
Any reccomendations on what to do at this stage? Anything i can try?
Please note im a pretty clueless mechanically but i am eager to learn (Not at the cost of an engine rebuild though! :P )
Extreme HDF Member
Joined: Jun 2014
Posts: 11,448
Likes: 2,299
From: NW Ohio
The exhaust stud bolts and nuts tend to rust due to the heat. Assuming they vibrated loose, they should tighten back up just fine.
It would be best to use a torque wrench to verify correct tightness, but it would be better to have them snugged up by feel than to have your pipe fall off. They don't need to be real tight.
If you intend to work on your bike, please get a service manual. It will become invaluable. This should be considered a mandatory purchase and they aren't expensive. Harley brand is better than Clymer/Haynes, but either is better than nothing.
Here is a screenshot of the relevant page from a book I happened to have on my computer. It should be very similar to your bike. Not much changes over the years with regard to exhaust. (You're interested in "Installation", step #5 & 6. Note the two-step torque procedure and the low torque value. 6 foot pounds (70 inchs divided by 12 = 5.8) vs the 75-100 that many car lug nuts require.)
It would be best to use a torque wrench to verify correct tightness, but it would be better to have them snugged up by feel than to have your pipe fall off. They don't need to be real tight.
If you intend to work on your bike, please get a service manual. It will become invaluable. This should be considered a mandatory purchase and they aren't expensive. Harley brand is better than Clymer/Haynes, but either is better than nothing.
Here is a screenshot of the relevant page from a book I happened to have on my computer. It should be very similar to your bike. Not much changes over the years with regard to exhaust. (You're interested in "Installation", step #5 & 6. Note the two-step torque procedure and the low torque value. 6 foot pounds (70 inchs divided by 12 = 5.8) vs the 75-100 that many car lug nuts require.)
Last edited by cggorman; Jun 8, 2016 at 10:42 AM.
Road Master
Joined: Feb 2007
Posts: 781
Likes: 35
From: St Louis
A small wire brush on them and a little anti-seize isn't a bad idea. Do be careful not to overtighten as is the tendency when things come loose. There are plenty of threads about broken studs. The anti-seize helps to keep them from taking the stud out with them if you need to remove the bolts at a later date.
check the nuts periodically. nothing more annoing than the pipe hopping of the studs during a ride and having to limp home listening to that bubble sound (happened to me a few times)
Thread Starter
|
Advanced
Joined: Jul 2015
Posts: 94
Likes: 9
From: UK
Thanks for the great advice guys, i'll give it a go either tonight or tomorrow morning and report results. I've got a few pictures of its rusted state i'll upload when i get home (currently in work so no phone)
Extreme HDF Member
Joined: Feb 2015
Posts: 10,907
Likes: 8,758
From: Galt's Gulch - MI
Just to build on what's already been posted, I tend to use a bit on anti-seize on the exhaust stud and double nut it with a chrome acorn nut; keeps the end of the stud protected and being it's a double nut, the exhaust nut doesn't come loose. Looks good too... 
Extreme HDF Member
Joined: Jun 2014
Posts: 11,448
Likes: 2,299
From: NW Ohio
Trending Topics
Tourer
Joined: Feb 2016
Posts: 309
Likes: 39
From: Southlake Texas
You need to be aware that the exhaust nuts are actually lock nuts. The rust, if anything, will help them lock even better. Just make sure you do not cross thread them as they go back on.
Also, the torque value is only 60 inch/lbs!! This equates to 5 ft/lbs. The average person "snugging" a bolt with a 3/8" drive socket wrench will put about 12 ft/lbs. So, do not overtighten these nuts! The desired torque is barely more than the resistence the locknut function provides. Another poster last week pulled the top front stud out of his head...and hasn't been back since. An ounce of care will prevent several hundred $ of repair in this case. You will not be able to strip anything if you observe the correct torque.
Also...as mentioned above, re-check the torque after the next several rides. The gasket packing takes a while to set, and the nuts loosen until it does. If the bike was run for some time with the flange off, the packing may be shot, so also check for exhaust leaks after you reinstall the flange.
Also, the torque value is only 60 inch/lbs!! This equates to 5 ft/lbs. The average person "snugging" a bolt with a 3/8" drive socket wrench will put about 12 ft/lbs. So, do not overtighten these nuts! The desired torque is barely more than the resistence the locknut function provides. Another poster last week pulled the top front stud out of his head...and hasn't been back since. An ounce of care will prevent several hundred $ of repair in this case. You will not be able to strip anything if you observe the correct torque.
Also...as mentioned above, re-check the torque after the next several rides. The gasket packing takes a while to set, and the nuts loosen until it does. If the bike was run for some time with the flange off, the packing may be shot, so also check for exhaust leaks after you reinstall the flange.
Last edited by CJD197; Jun 8, 2016 at 05:07 PM.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Extreme HDF Member
Joined: Jun 2014
Posts: 11,448
Likes: 2,299
From: NW Ohio
Pretty rusty (or maybe just dirty?). Assuming rust, I'd suspect the studs came loose before those nuts, but it's hard to tell from here. I would definitely clean them up as good as I could with a steel brush then soak them with a good penetrating oil for a couple days before I made further judgement.
Those studs are WAY longer than the ones on my '99. Did they make them longer on the newer bikes?
Those studs are WAY longer than the ones on my '99. Did they make them longer on the newer bikes?