Need some pro advise....

[JMBT]

Last night was a BAD night. We left out from my brother’s house yesterday headed for the east coast with our new trailer on its maiden voyage. Everything was great for 940 miles. I had been checking all of the systems regularly, coolant, oil, trans cooler...etc since brother and I had had all of them apart for the vibe dampner replacement. Everything was operating as intended with no leaks. I was also hand checking all the bolts we had removed and retorque and all were tight.
Then about 2 am, I had been sleeping for about 2 hrs and my wife was driving. She woke me up saying that the battery voltage light had just popped up on the dash. I figured the alternator had probably taken a crap on us since it is original at 635K. She hit the shoulder and I hopped out and flipped open the hood. The main fan belt, (brand new), was shredded. And all 12 of the bolts that hold the vibe dampner and main pulley to the crank shaft nose had came out about 3/8” allowing the main pulley to jack sideways and explode the belt.

Now, what would have made the bolts all come loose?? I torqued them in a star pattern as Cummins suggested to 129 ft/lbs. I did antiseize them, but figured that would be fine as Cummins reccomended lubing them with engine oil during assembly. Was it the antiseize?? A faulty torque wrench?? What do you guys think?

Next question, when we hit the shoulder the coolant temp jumped to about 240 degrees. I had to shut it down hot because we had no fan or coolant pump, as the man belt was gone. The ECM logged a fault for coolant over temp at the least severe level. But what should I be looking for in the way of damage due to shutting down with ultra hot coolant?? Also EGT were around 500 when I had to kill it. What could this have damaged and what can I check?? The coolant temp dropped fast as it was about 30 degrees out and after I made the repairs the truck was running fine.
Today I pulled it all down again. Took the pulley out and inspected it for damage and it looked fine. I cleaned off the antiseize from the bolts, applied blue 242 loctite and retorqued all the bolts to 129 ft/lbs. I am parked tonight but will check the bolts with the torque wrench several times on the rest of my DH tomorrow.
Any ideas you guys might have for things to check will be much appreciated. Thanks.

[Hammerhead]

I'm not a "Pro" but I'll offer my opinion.

I'm very curious why your came loose. My QS says torque value is 130 ft/lbs, but one more foot pound of torque won't matter. I also anti-seized the bolts. A very light coating, but silver grade none the less.

I've actually had mine off twice, don't ask why, but it was still tight when torqued properly both times, leaving me wondering why you had issues.

Dumb question, of course you painted the new one, but did you paint the mating surfaces? I primer'd mine with one thin coat, then I masked the mating surfaces and painted the damper with several coats, white lettered the markings, and put 3 coats of clear on. Is it possible that the paint compressed/wore on your mating surfaces causing the damper to be able to move and work the bolts loose?

The risk of heat damage is low, you were at "Least Severe Level". Shutting down at those temps isn't advisable, however unless it is routine it rarely causes major issues. You had no choice anyhow, so it is what it was. Monitor coolant levels and I would Sample the next two (2) oil changes if that's not your routine just to be on top of things.

I've blown turbos before under "full pull", and had to shut down too while it was smokin hot. Not my ISX, but a couple of times with S60's and once with a Big Cam 3, and never damaged anything other than the turbos that were already broke anyhow. The turbo would be my biggest concern, but monitor it, don't just change it.

[JMBT]

Hammer, thanks so much for the response man. I am freaking out here.
I did paint the mating surfaces on the front and back of the main pulley, also the plate that rides in front of the pulley. The dampner got total coverage as well. Prime, paint, and clear on both sides. All the mating surfaces were coated from the factory with what looked like back paint so I didn’t think twice, but what you said makes since. That could make them work loose. Weird that your QS says 130 and mine 129?? WTF? When I put everything back together today, I scruffed the paint off the mating surfaces with some parts cleaner and a Brillo pad, (that’s all I had), except the front of the dampner itself, it stayed the same. Also I threw the 242 blue to the bolts after cleaning off all the antiseize. Man I hope that does it. I will be doing a lot of monitoring in the next few trips. Will know more on the turbo when I get running tomorrow.
What do you think on the faulty torque wrench theory??

[dhirocz]

Did you torque the bolts with an extension? An extension, especially a long or smaller one, will lower the torque to the bolt.

I know online somewhere there is a formula to calculate this torque loss when tightening fasteners.

I also put a drop of oil under the head of the bolt. Something I've been doing since I started building engines.

After that I think I'd replace those bolts. Are you sure on that spec? When I did mine last year, I could have sworn it was over 200 ft/lbs.

[Rawze]

Your very lucky that your problems were not much much worse.

Did you have the key-way pin aligned in the damper properly? It sounds like the damper was not seated all the way. - If not, then the whole damper would not be seated properly and will suddenly come loose after finally slipping until it dropped into the key-way.

Also, If you have performed an overhead valve adjustment with the new damper, it not in the key-way properly, then the overhead valve adjustment could be incorect too. Just something to think about.

Excess anti-sieze is an unlikely a possibility at 130 ft-lbs but can happen? That is quite tight. Are you sure your torque qrwench was not on 130 Nm instead?.

Double check all that stuff and when it comes to anti-sieze, I always use only just enough to turn the the threads a bit grey and not much more. It really does not take much.

Same thing if you are using lock-tite. It does not take very much and in fact, lock-tite works better if you let it completely dry into the threads before installing the screw. using too much will make parts expand as the stuff dries and create problems.

[Starlight]

I would guess something is wrong with your torque wrench. When you tightened those bolts did it feel like 130 ft lbs or did it seem low? I ask cause I have personally never seen something like this and also because I would have been able to tell if my torque wrench would have in error been set to nm instead of ft lbs like Rawze said. Also I assume you have a good quality torque wrench and not a cheap mastercrap or the likes. I also can't see a film of paint do this, anyway not so quickly after install.

[JMBT]

   Rawze and Dhirocz, thanks for the feedback guys. Rawze: yes I am positive on the key-way or dowel pin, it was properly aligned and everything was seated perfectly when we did the initial install. The torque wrench was set in lb/ft, but I am questioning it’s accuracy because it is old and a cheap unit to boot. When I retorqued today it was with a brand new, supposedly calibrated, wrench I bought today.
Dhirocz: I am positive on the spec. See pic. Yes I used an extension, but I was thinking a straight extension regardless of length did not effect torque? Only a Crow’s foot or swivel would change torque output??

[JMBT]

Thanks Starlight: yes it is very weird to me too. Not my first rodeo and I have never seen the likes of this either. The wrench I used at my brother’s the other day is old and cheap, so it could be the culprit. I bought a replacement for it today. Strangely though it actually felt like much more then 129 ft/lbs when I torqued the first time. I was leaning over the front bumper in a awkward position, and it was a short wrench to boot. I felt like I was going to blow my arse out to get the 129 ft/lb click. So odd I checked and double checked the wrench multiple times to assure it hadn’t slipped to a higher setting, but it was dead on 129.

[Rawze]

(11-26-2017 )dhirocz Wrote:  Did you torque the bolts with an extension? An extension, especially a long or smaller one, will lower the torque to the bolt.

...

{some humor here, not being psarcastic}...

One of the oldest arguments in mechaincs shops that spreads like a virus that has ever been originally thought up long ago by those who still thought the earth is flat, the moon is made of cheese, and that elvis is still alive.

A wifes tale -- an urban legend -- Internet trolls fodder to start arguments with -- nothing more!


Not even if he was using several feet of extension bar. Sorry, but it simply goes against the laws of psychics.








The only thing that happens even in worse case scenarios is that that the wrench swings further around to produce the same torque than before due to spring force loading. For energy to be somehow lost in the extension bars then they would become red hot from the absorbed energy. The energy has to go somewhere. <-- Hey I know --- It goes to the other end!.

--> Torque a bolt and mark its position 3 or 4 times. Go torque it again with the longest extensions you got for that size wrench. Be sure to hold the wrench squarely each time to the bolt head (changing the angle by more than a few degrees at long distances will change the torque however) . <- You will end up the same exact place every time you do this test. <- I used to make bets with people all the time over this in shops and win money over it. -- even when i proved them wrong time and time again,.. they would still argue it away because no one likes to be made a fool of or be proven wrong.

Last I checked, extension bars were not made of soft energy-absorbing rubber.

===

Sorry to be sounding so harsh with this answer, I am not trying to slam the original poster. It is an easy one to get wrong because there are so many 'flat-eathers, psysics don't exist' out there on this one ... I am sure he has been taught this by some other moron who learned it by some other moron and so fourth. -- At some point reality has to step in and bad information needs to stop. .. My rant is not towards any individual here ... Trying to prevent an all out argument on this ... I just can't stand urban legends that continue to spread like a virus on the Internet. especially on this forum whenever it can be helped. If someone still disagrees strongly, then I suggest they take the argument somewhere else if they want to piss reality and physics away because it does not exist for them. I am sure someone can find 1,000 mechanics web sites and forums with the same argument all over it. Please keep it away form this one, it is a dead horse that will always cost someone a $20 bill if I had been standing there.