One Time use Muffler clamp?

Discussion in 'Touring Models' started by bernhardz77, Jan 11, 2009.

  1. bernhardz77

    bernhardz77 Member

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    Hi everybody,

    I have performed my own stage one upgrade with the Air filter and screaming eagle pipes. When I bought all the components, the parts guys sold me two new muffler clamp, saying the old ones shouldn't be re-used. The installation instructions from HD said the same. First I considered this the normal HD/Dealer nickle and dime, but now I am starting to wonder.

    I am having trouble getting one on the slip-ones to stay in place. I have tried tighten the muffler clamp several times to spec, but after a short ride, the slip-one always slips back against the back-stop under the saddle bags.

    I thought I figured out that one of the slip-ones might be stopping the clamp from tightening correctly so I filed down the edges slightly (see picture one)before the last try. Still no dice.

    Here is my questions. What makes this clamp (see picture two) a one time use only part? What could be happening that one doesn't stay tight. The other side stays in place after one additional tightening.

    Thanks

    Bernhard
     

    Attached Files:

  2. Bud White

    Bud White Well-Known Member Retired Moderators

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    Don't have any burrs in side the slip on ? I have heard of people having this problem of the slip on loosing up and having to replace the clamp.
     
  3. flh canuck

    flh canuck Active Member

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    I suspect the "one time use" is in relation to the bolt and nut used. It is a self locking type and after repeated use, the nut may loose its self locking ability.

    That being said, I have re-used the clamps with no particular issues.

    If your muffler keeps slipping off and you utilized a new clamp, there are a couple of things you can try:

    -another new clamp but torque beyond factory specs (carefully)

    -exhaust sealant where muffler slides on ( may help)

    -obtain a pipe expander from muffler shop and slightly expand header pipe where muffler slides on.

    Good luck!
     
  4. whatyardwork

    whatyardwork Banned

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    Todays modern metals are coming in more and more variations from very flimsy sheet steel to ultra strong Borron steel.Basicaly its all about how tightly compacted the molecules in the steel are that determine there stregnth.With any steel heat is the enemy.Introduce a little heat and the molecules expand creating week points and flexibility.Take a beer can for example, press lightly with your thumb to create a small indent.Now press lightly on the edges of that indent and it pops back to shape.Thats a property of metal called elastiscity, basicaly it wants to retain its origional shape.Now press a little harder creating creases on each side and it will no longer bounce back to form.Thats called work hardening.A bunch of molecules once evenly distributed are now bunched up very close together creating a strong point.Your bracket contains no work hardening or true strong point so over time with introduced heat the molecules are allowed to spread out and weeken the component.If you where to re bend the end with vise grips, taking out some of the slack in the bracket and then simply add a mig tac weld on that side { introducing work hardening } it would be useable again.
     
  5. paulb5

    paulb5 Member

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    A couple of years ago my Road King developed a nasty squeek. It was caused by a bad muffler clamp. Dealer told me the same thing "one time use".
     
  6. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    One time use on muffler clamps and bolts subject to vibration, heating/cooling OR exposed to long term evironmentals. Those fancy chrome bolts, can develop hidden rust and usually torqued (tensioned & stretched), locked on with Locktite. Very hard to reuse without scoring the plating and their not particularly "hardened" hex head allows stripping or corrosion to set in. Replace fasteners if doing it on long life components...cheap insurance JMHO. :s
     
    Last edited: Jan 13, 2009
  7. glider

    glider Veteran Member

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    These clamps are billed as a one time use but can be used a second time with satisfactory results. A bit of penetrating oil on the threads before removing them helps a bit to prevent the galling of the threads that occurs.

    Now as far as the muffler slipping off, make sure you get the clamp right up to the leading edge of the muffler over the "slots" that are cut into it which would be to the extreme left of your picture below. Moving it rearwards (to the right in your pic below) diminishes the clamping force because it cannot close down the inlet to clamp on to the pipe sufficiently .

    [​IMG]
     
  8. bernhardz77

    bernhardz77 Member

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    Thanks for all the input.

    I am going to try a new clamp and take all the advice into consideration when I put it on.

    Thanks

    Bernhard
     
  9. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    Along the same lines, if trying to "salvage" a fastener that has Loctite and been on for a long time, what is the easiest way to loosen/break them loose. I have tried heat, but sometimes "stubborn" is the operative word (others' could get one of those "bad boy" PMs)!:newsmile055:
     
  10. glider

    glider Veteran Member

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    If it's the red locktite, heat is about the only thing to get it to release other than muscles and a prayer. :s