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View Full Version : New Harmonic Balancer Needed?



crashz
10-22-2009, 20:50
My 87 has been used hard over the years by the previous owners (a farm and a city DPW), but does not have a lot of miles on it. It is in need of motor mounts and a transmission mount as well as all of the bushings on the front and rear leaf springs.

My question for you guys is: Should I be concerned about the condition of the harmonic balancer considering that its 22 yrs old? With the cracking block problems, I want to keep this engine healthy and running and would rather spend a little now to keep her going.

Subzilla
10-23-2009, 05:36
You might should think about it, sure enough, but a visual inspection will confirm a needed replacement. If you see any cracks in the rubber or any protuding pieces of rubber or any non-uniform shaping of the rubber, replace very soon. A new dampener is a whole lot cheaper than an engine!

Robyn
10-23-2009, 07:01
After 22 years the Ballancer should be considered a throw away item.

Now rhat said, if the outer steel rim is still located where it needs to be and the rubber is not protruding anywhere the thing is likely not a real danger.

I have pulled 6.5/6.2's down that were cracked up badly in the lower end and the ballancer was perfect.

A bad ballancer can and will contribute to a broken crank in these engines and will certainly hasten the spread of main web cracks due to the bad vibes that can result.

Now again, that all said, the total reason for main web cracks in these engines has many casues, none of which have ever been pinned down as the smoking gun.

One reason that I am sure of positively (IMHO) is the metalurgy and the design of the block.

I have seen 6.5 TD's that have had the rat crap run out of them and are totally crack free.
By the same token I have seen Burbs that were MOMS house car that have had the blocks fail under very light usuage.

The one indication that makes me say "Metalurgy" are the blocks that I have seen with the main web cracks the form at the register fit of the main cap/block area and have spread open to the tune of .020-.030 "

This points to a problem with the metalurgy and also likely poorly cured castings.

Good Iron that is stress relieved prior to machining just should not do this sort of thing.


Best

Missy

crashz
10-28-2009, 11:19
I looked at it this weekend and the balancer seems to be in good condition from the outside. Right now I have other minor repairs to make, so I'll work my way up to it.

Thanks for the advice!!