Harmonic balancer

[diablostang]

Hey guys,

I think my harmonic balancer is dead.. The drivetrain of the car vibrates bad... especially under load. I've considered the driveshaft, but Im thinking that's not it... It vibrates when revving in neutral, though not nearly as bad (since it's mainly under load) anyhow, it's bad enough that the shifter slaps the tranny hard, and it pops it out of 5th gear... not fun

Recommendations for a good replacement? I don't want to spend much money, already got too much into it... I'm going to check the motor mounts just in case, but I doubt it's that.

Thanks in advance :SNSign:

PS: I'm talking about the 94.

 

[Yobi1Kanobi]

hey diablo i have a stock unit that might get u by if u want...it is in good condition it just came of my 94 im doing a complete built and its a 50 oz unit I need a 28 oz

 

[diablostang]

I think I need to go new, since the stockers tend to let go of life so soon... thanks though.

 

[wytstang]

I went with this one (very happy)
http://mustang.c-f-m.com/index.asp?PageAction=VIEWPROD&ProdID=353
Better one
http://mustang.c-f-m.com/index.asp?PageAction=VIEWPROD&ProdID=355

 

[Cobra4075]

Went with Professional Product SFI balancer. I haven't run the car yet, but it apperars to be a quality piece and was not crazy expensive.

 

[Yobi1Kanobi]

looks like a nice piece price aint bad either

 

[DFG 5OH]

damn, i might be getting that pro products one soon!

 

[diablostang]

Cool, those look good at good prices!

 

[HISSIN50]

I would not hesitate to use the PP unit myself. I would have but it was backordered when I wanted to order one.

Honestly, I have to say that I hope the HB fixes it. Given what you posted, the balancer is not where I would look first.

Good luck.

 

[SeventyMach1]

A buddy of mine runs that one in his 347 notch. (2nd one Danny posted) He bought it new from Doug Herbert Racing for $90 & says he will never use any other kind. I will be using one of those as well.

 

[HISSIN50]

A buddy of mine runs that one in his 347 notch. (2nd one Danny posted) He bought it new from Doug Herbert Racing for $90 & says he will never use any other kind. I will be using one of those as well.

Gonga deal.

 

[wytstang]

Gonga deal.

+1 $90 for the SFI is awesome. Do they have a web site?

 

[95strokerPSU]

I have a Pioneer SFI unit. My engine builder recommended it and it was only $130. Quality piece too.

 

[SeventyMach1]

Wow ... I just finished browsing their site & their prices are actually the same. Here is their site: http://www.dougherbert.com/index.php


The Herberts are a drag racing dynasty ..... fortunately their racing shop is only 10 minutes from me. Maybe that's how he got such a good deal ..... buying direct from the shop.

 

[94gts]

a little off topic but what makes a balancer go bad and how do you know if it has been "spun"

 

[HISSIN50]

a little off topic but what makes a balancer go bad and how do you know if it has been "spun"

There is an inner and outer ring that are joined with an elastomer (round piece of rubber). The balancer quells torsional vibration which is why this piece needs its full structural integrity.

Over time, the elastomer wears out. It can crack (which theoretically reduces its effectiveness alone). But normally once the rubber starts to let go, the outer ring starts to spin against the inner ring (rotational inertia at work). So if someone finds that their timing marks are way off, but timing had not been changed, for instance, that is a sign. Often the outer ring will slide longitudinally (toward the motor or away from it) on one hemisphere (it looks like someone hit it with a hammer on one spot).

To answer the question, getting the motor to TDC and noting the timing mark alignment is one way to see if the outer ring spun. Normally the elastomer will look like poo by the time this occurs (it can get cracks in it before it starts to let the outer ring spin).

I would surmise that heat is what takes care of the elastomer (it cracks, vulcanizes, etc). That and lots of rotations................

 

[94gts]

So if someone finds that their timing marks are way off, but timing had not been changed, for instance, that is a sign.

OH ****! i had that problem all summer. But nothing seemed out of the ordinary?

 

[BlownFiveLiter]

Try e-mailing Ed Curtis. He has some stuff listed on the Corral forums, and had some Romac balancers for pretty cheap (like $239 if memory serves me right).