PSA - Be very careful when torquing the damper plate retention bolts

[doubletee]

(This is cross-posted from the Valk Facebook page).
Replaced the dampers in my rear wheel. Snapped off one of the bolts when torquing them down. I was lucky enough to be able to remove it with an eze-out, but I was really panicked until I got it out. That plate is held in place very tightly by the pressure of the dampers and isn't going anywhere even without the bolts. I plan to just lightly snug them up with a dab of blue loc-tite once I get the new fasteners.

[old2soon]

Forgo the Loctite and just snug them up. Been doing that to mine for the last 74000 + miles. I also just snug the exhaust header nuts. Breaking bolts is a royal P I A. RIDE SAFE.

[Steve K (IA)]

Forgo the Loctite and just snug them up. Been doing that to mine for the last 74000 + miles. I also just snug the exhaust header nuts. Breaking bolts is a royal P I A. RIDE SAFE.

The Only time I have ever used a torque wrench has been on my Valks.....the axle nuts.  Then again, I don't even think I will do that again.  I know when tight is tight.  I haven't snapped a bolt off anything, and no bolts that I have tightened ever came loose or refused to back out when the time came.

My "feel" hasn't let me down in all these years.  (knock on wood)          

[Patrick]

Thats a shame, I don't like to hear that.  At times bolts break when trying to remove them. Its shame to break them while installing them. I'm wondering why they broke. I see folks almost every day using a torque wrench improperly.  Its nice though when the stub comes out easily.

[cookiedough]

Only time, knock on wood,   have broke a bolt so to speak is when trying to remove a stubborn spark plug on my dad's 1986 caprice classic car that were in there for sure guessing 80K miles or more only replaced once am sure car had 165K miles on it.

I sprayed it with everything I had and when I felt it unwind on my socket,  I thought for sure I got it until I just saw the white porcelain of the plug darn it.  Had to take it to a local shop with a lift to get it out from underneath with an easy out tool they had. 

[Patrick]

I think I've broken about a bazillion fasteners trying to remove them and have learned or been taught a lot of tricks over the decades, but, it still happens once in awhile. Most are exhaust manifold fasteners.

[Paladin528]

Generally speaking there are two reason that bolts break when either installing or removing them.
1) Corrosion.  When the boolt corrodes to the point where the metal in the bolt fuses to the metal in the hole.  This is generally the most common issue.
2) Over torque.  Toquing a bolt sets a predetermined "Stretch" on the bolt.  This is designed for two things.  one it to ensure the two pieces being mater are joined sufficiently for strength and 2 is to prevent the bolt from becoming loose.
When there is no visible corrosion or visible damage to the bolt and it breaks you can bet that at some point that bolt was overtorqued which led to fatigue and failure.
The torque wrench is your friend and although "Feel" may get you by, eventually it will bite you in the ass.

[indybobm]

There is been a lot of disussion over the years about whether or not the Rotor Bolts and Damper Plate Bolts are TTY or Torque To Yield.
Here is what I tried years.

If you do not think that the bolts are ' torque to yield', then do a little test. Take either the rotor bolts or the bolts for the rear wheel damper plate and do the following:

1. Measure the length of the bolt with a digital caliper
2. Install the bolt, without thread lock, and torque to the stated amount.
3. Remove the bolt and measure again with the calipers.

You will find that each time, the bolt has become longer. You will also notice that the diameter of the threaded area has become thinner as the bolt stretches. Eventually, you will not be able to torque the bolt to the stated torque without the bolt failing.

I did this test on the damper plate bolts and the rear rotor bolts when I replaced the final drive on my bike.  I torqued the bolts to the spec in the service manual. Some bolts stretched well over .050" over the original length and did not return to the original length. The thinning of the middle  threaded area was very noticable. Eventual they will snap when trying to torque them to the specified amount.


 

 

[Paladin528]

Those are normally identified in the manual as REPLACE. 

[indybobm]

Those are normally identified in the manual as REPLACE. 

That is true in some cases. Honda wants you to replace the gasket on the oil drain bolt. Not always an indication of being absolutely necessary.