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Old 08-25-2017, 10:49 AM
JeepSJ JeepSJ is offline
Jeep Freak
Join Date: Sep 2003
Location: Feeniks, Aridzona
Posts: 1,108
Default Check those harmonic dampers!!

The duallytruck had developed a bit of a higher-rpm vibration. Fan clutch was failing and I figured they were related as the fan had a lot of play. So get a new fan clutch and start the job. Crawl underneath to unbolt the fan shroud and I notice that the outer ring of the balancer is resting against the back of the lower pulley.

So I pull all the belts and unbolted the lower pulley and the outer ring slid right off.

I've heard about that happening but have never seen one actually come apart. Inner, outer and what is left of the rubber. Amazing how smooth that 454 is with a new balancer. I am just VERY glad that the pulley was a larger diameter than the ring. I could not imagine what a chunk of iron that size could have done had it come off on the freeway.

Now that I think about it, I should check the timing also...there is no telling how long it has been loose.
1987 Jeep Grand 6.5 in process...diamond block, 18:1's, other goodies...

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Old 08-26-2017, 06:38 AM
Robyn's Avatar
Robyn Robyn is online now
Missy Good Wench ( Moderator)
Join Date: Apr 2001
Location: Newberg Oregon
Posts: 9,758

Been many a 6.5 that have died an untimely death due to balancer failure.

The serp pulley also has a rubber isolate'r that kills the belt vibrations common to the diesel.

The isolate'r has a bearing assembly and a metal spider to support the pulley, and when the rubber breaks its bond with the internal ring they hammer like crazy and will trash a crank in sort order.

I have seen balance'r rings get loose, IT AIN'T PRETTY

When it happens at freeway speed the driver usually needs a change of shorts

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(1) 95 Suburban 2500 4x4
(1) 2017 Mercedes C class
(1) 1997 Astro
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