I am have been looking for a firebird with a v8 for a while now and I have finally found one. The guys says that the only problems he knows of are the harmonic balancer is wobbling from a sheared pin and an exhaust leak at the headers. My question is how hard is it to replace the harmonic balancer and about how much will it cost if I do it at home? It is a 305 carb in an 89. Thanks for the answers.

 

AutoZone should loan you a damper puller, gratis. But you're gonna have to pull it to see what the problem is, if any. Best to pull it, then get us some pics.

 

I dont think a sheared key is the reason it wobbles.

 

Agreed with above. A sheared key would be very bad for it's own reasons (the crank keyway is not really repairable and usually gets chewed up if the key shears off, often accompainied by the balancer falling off while running) but doesn't necessarily equal a wobble.

A wobble could be just the balancer but could also be a bent crank snout (like if somebody dropped the engine or jacked up the car underneth the balancer). A bent crank snout is also a game-over scenario for the crankshaft.

Dig into the "wobbling balancer" issue further before laying your money out.

 

If indeed it is your harmonic balancer, you should consider switching from a stock balancer to an aftermarket one. Stock dampers just do not provide the protection needed on performance engines. The only reason manufacturers use the stock dampers is because of cost. I would recommend using Fluidampr performance dampers. Here are some of the facts from there website www.fluidampr.com.


When performance enhancements are made or added to a stock engine to increase horsepower and torque, whether for commercial, pleasure or competition, the increase in performance overworks the stock damper because of its inherent inability to self tune to the increased harmonic vibration generated. This results in diminished engine protection.

Dampers also create heat while they work; elastomer (rubber) is a poor dissipater of heat. Heat and exposure to the elements, oils and solvents deteriorates the elastomer (rubber) causing it to crack and/or change durometer. Eventually this causes inertia ring slippage, uncontrolled torsional vibrations, damper failure and costly damage to engine parts.

The Fluidampr design incorporates a totally sealed laser welded housing encasing a precision machined inertia ring, suspended in a thin film of highly viscous silicone fluid. The viscous silicone fluid allows the inertia ring to shear the harmonic vibration from the engine, regardless of any performance enhancements that have been made to the engine. This is possible because the Fluidampr is frequency insensitive, able to self tune to the exact frequency bandwidth of the engine harmonics at any given range.

The advantage is clear...

The silicone fluid used in Fluidampr is a clear gel and is more than 45,000 times thicker (more viscous) than 30 weight motor oil. Silicone fluid is an excellent damping medium because of its tensile strength, density and low

friction properties. The silicone allows the inertia ring to rotate freely within the housing, tuning to the harmonic vibration generated with every stroke of the engine. The silicone is also thermally stable providing consistent damping in all weather. Fluidampr viscous dampers never have to be tuned or rebuilt and in performance application will never wear out. Be leery of damper manufacturers that state their “damper should be rebuilt or tuned.

Hope this helps with a better understanding of how important a good damper is.

 

Why buy an expensive damper for a near stock 305? About $60 will get you a perfectly good one from Autozone.

 

stock or near stock. $60 perfectly good one... well opinions do vary!

I am unaware of what performance enhancements have been made. Again, stock dampers are only designed to function throughout a narrow predetermined frequancy bandwidth. If there are performance upgrades, this will change the frequancy not allowing a stock damper to perform properly. There is an ol sayin my granpappy told me once... you get what you pay for! Not to mention with Fluidampr you gain horsepower, torque, improve valve timing accuracy, and ignition stability. If you dont care about your engine, crankshaft, bearing life, etc buy the $60 damper. I was just trying to offer some education on harmonic dampers.

 

The engine with the stock type $60 damper will last just as long in a street car.