LT4PWRD

Since I have my LT4 on an engine stand in the garage, I am replacing several items that are now easy to access. Upon close inspection of the Harmonic Balancer or Crankshaft damper, as it is referred to in the manual, I noticed that the rubber gasket is cracking. I searched the archives and determined from other posts that I should replace the balancer. I have two questions:

1) If replacing the balancer/pulley or outer hub, would it be wise to also replace the inner hub as well, or is that not necessary?

2) I noticed that there are two metal dowels in two of those small holes around the outer edge of the balancer. I am assuming that these help with the balance, such as weights added to a tire/wheel. Is this balanced per Balancer, per engine year or per individual engine? In other words, will I receive a balancer that is already balanced or do I need to transfer these metal dowels from the existing balancer?

By the way, I found the excellent write-up in the archives from PurpleC4 regarding the removal of the Balancer assembly, it is more detailed than any of the manuals that I have (Chilton's, Haynes and Shop). I appreciate your write-up PurpleC4.

Thanks,
Chris - 1996 LT4

Togo

hey crt, i envy you
you get to change it while the motor is out!
i had to change mine with it in in my '85
not a pleasant experience at all.
the balancer is 'balanced' per balancer, or at least it was with my '85. all i did was go to checker auto and buy a balancer and mounted it on.

as for replacing the outer and inner, they are one piece if you buy it....so you really can't replace one without the other. or at least that is the way it is on mine!

hope this helps
good luck

LT4PWRD

85_togo,
Thanks for your input. Is there any other members out there that have replaced their Harmonic balancer? I was hoping to get feedback form several experienced members.

Thanks,
Chris - 1996 LT4

Ron78Z&66Vette

I recently changed mine on my 85 Vette, and a couple of years ago pulled it on my 95 LT1 Z28 to mount an underdrive pulley....
The L98 and LT1/LT4 balancers are completely different.
The center "hub" that the LT1/LT4 balancer is just a mount point for the balancer. There's no reason to replace it.
As far as the balancer being balanced for the individual engine, I really doubt it (if someone can prove me wrong, please do). I sold my 95Z (and the Helm's manuals), so I can't check for sure.

AquaMetallic94LT1

Make note of the positions of those dowls. They are balance weights which must be installed in the replacement balancer in the same positions. The LT4 balancer is 200 bucks so I would look at some aftermarket balancers like fluid damper in addition to the stock one.

LT4PWRD

Ok, now I am back where I started. Ron doesn't believe that the balancer is balanced for each individual engine, and I would tend to agree with him. Aqua believes that I should transfer the metal dowels from the original balancer to the replacement, which would indicate that it is balanced on a per engine basis. Well, my Helm's shop manual agrees with Aqua, indicating that a replacement balancer should use the same size weights in the same location as the original balancer. The reason that I started this post was because I had a hard time believing that the shop manual was correct (indicating that the balancer is balanced for a particular engine as opposed for a particular balancer). There are probably members out there that have taken both approaches. FOr those experienced members, which way did you proceed when replacing your balancer and what was the results.

Thanks,
Chris - 1996 LT4

mikey

your engine is externally balanced by both the front balancer and the flywheel.. anytime you change one of the components, the new one should be matched to the old one. if you have the whole motor out of the car i'd suggest having the whole rotating assembly balanced..

doug rippie's position on balancers when i talked to him is that the stock piece is very good and at $80 is a better value than buying an ati/aftermarket piece. i'd suggest dal slabaugh at van devere olds in ohio for best dealer pricing.. email me if you want his phone number or do a search on the forum for dal.. it'll come up.

good luck,

NoWorries

My L98 was also going bad when I pulled the motor out of the car. Even though my rotating assy is balanced, the guy that did all of my machine work recommended getting a harmonic balancer(he calls it a torsion damper) for an externally balanced motor. He got me one for $56, guaranteed it will last longer than the motor...and that it is what he puts on all the SBC's he rebuilds unless something else is requested.

He also said that "Balancer" is misleading, it really is just a harmonic/torsion damper and that the balance part only comes from it offsetting the vibrations caused by the crank shaft, and only between a certain rpm range.

I'm not sure which "inner hub" you are talking about, as the hub that it is on is the front of the crank shaft on the L98.

Good luck.

Ron78Z&66Vette

Cool......Guess I learned something about LT1's/LT4's today.

65Z01

The balancer consists of two metal rings with an elastomer separating them. The inner ring is keyed onto the crankshaft. When you pull the balancer the assembly comes off the crankshaft.

In some catastrophic failures the outer ring separates from the elastomer. In such case you will remove them separately.