i have heard some real horror stories about the harmonic balancer goin out? how much vibration is too much? i am wondering how do you tell if the balancer is bad? i have looked at it and all the rubber looks good, no cracks. sometimes i have a little vibration at idle and sometimes i dont. Edited by: steiner43511

The serpentine drive pulley is also part of the harmonic balancer system, with rubber isolaton between the hub and sheave.


Check it for cracks\deterioration - observe for wobble\shake.


Observe belt for excessive flutter, tensioners for excessive travel when engine is idling.

so is it really the balancer that goes bad or is it just the pulley?


my belt is only a month old, and the rubber isnt cracked on the pulley. i can push the rubber in a little but it is pretty firm.

Yes, it is really the harmonic balancer that fails.


And, yes it is really the drive pulley that fails.


Both require occasional inspection, due to oil spills at oil change, and ozone, and coolant heat from radiator.


I check them at each oil\filter change - part of a good routine preventive maintenance program on a 10 year old drive train.

well the current budget right now is only 300 dollars. cant decide on gauges or a new balancer and pulley.


when i look at my balancer and pulley, i dont find any signs that they are bad. and when it is runnin they dont shake any. but there is still a slight vibration. maybe it is a clogged injector or something else though.

The rubber isolator in the balancer will 'ooze' out when failing. The outer ring is pressed onto the inner hub, over the rubber isolator.


The drive pulley will show 'webbing' cracks, pieces missing, flaking. The 'sheave' is bonded to the hub, via the rubber isolator.


If all ok, go for the gages

what do you mean by 'ooze' out? is the rubber supposed to be flush with the outer ring and inner hub when looking at the side toward the engine? mine is sticking out just a little bit, maybe an 1/8" but it looks pretty uniform all the way around. hard to see up in there. i cant find anybody in town that stocks a new one so that i can compare them.

I would LOVE to see pictures!~ http://www.dieselplace.com/forum/smileys/Clap.gif

Check the back side with a mirror, compare to the front side - if it is uniform around the circumference, front and back, then all is well.


Sorry, charlie - no pictures, just the thousand words.http://www.dieselplace.com/forum/smileys/Cool.gif

d***!
Last time I pulled the balancer it did look like the urethane was oozing out.
and It's not in the budget at all.

Why did you pull the balancer?

I was replacing the CPS(crank sensor) and I thought it was a good time, I had the radiator out and all.
I thought I had felt some cracks in the pulley and the harmonic is right behind it, why not.Edited by: quantum mechanic

CPS = Crank Position Sensor?

My truck has been idling a little rough (or an engine missfire at idle) lately and it just occcured to me to check the balancer this afternoon. I crawled under the truck and looked at it from the back side. About a 2" piece of the rubber is missing.


Is it likely that a new balancer will fix it?


I will be getting a ride to work tommorow and hopefully can find one in stock somewhere along the way.

Dunno about the rough idle, but if the balancer is as bad as you say, replacing it will save your crank and block.


Might also check the accessory drive pulley rubber webbing for cracks - no matter how slight the crack or tear, it will only get worse.

No where had one in stock so I had to order it.


I pulled it off today and it isn't as bad as I thought it was.


http://www.dieselplace.com/forum/uploads/6CZ_balancer.jpg


But I did find another problem. When I went to pull the pulley off after removing the bolts, (it was stuck to the balancer) it turned back and forth about 3/4" and wobbled. I was affraid the crankshaft was broken. It turned out to be a sheared key in the balancer. I didn't even need a wrench to get the balancer bolt out. Two fingers easily turned it out. It looks like it has been spinning some on the crankshaft. Is it likely to cause probalems with the new one with the shaft worn?


Is there anything else I should do while I have it off? The crank pulley is only a few months old. The front of the balancer looked fine (and still does) so I didn't replace it at that time. I think that the broken pulley rubber back then may have caused the key to shear.

Try the new unit on the shaft - wear may be in balancer hub, only..


The bolt must have been loose for a long time, letting that huge counter-balance mass rock backerds and forerds.


Might also want to pull the oil pan, check the three center mains for cracks in the webbing


Don't forget a new crank seal for the timing cover.


New timing chain set while it's down?


If everything is jam up and jelly tite, be sure and crank the bolt down to 200 ftlbs


I think you may also have found the rough idle problem......