Bad Harmonic Balancer What To do??

[96turboSuburban]

Hi All,
My Harmonic balancer has just self destructed at 165K miles on my 1996 1500 GMC Sub. iwth a 130GPM cooling dual thermos and run Amsoil synthetics. I know to replacethe H.B. and the drive pulley and the serpentine belt. I tow a relatively light camper at under 5000lbs. What else can I do to confirm that the crankshaft and block are still in decent shape?? Should I drop the oil pan to look?? Should I buy the mains girdle to stiffen up the lower end?? I have a larger Kennedy exhaust and plan to up the boost a bit on the turbo if the engine is still in good shape.
Thanks in advance for your help!!!!
Todd

[turbovair]

I personally don't think you will be able to see much of anything with the pan off. Loud, obnoxious, clanking/clunking noises coming from the engine would indicate the crank MAY be cracked. I doubt if you could spot a crack visually. If it were big enough, return to loud obnoxious clanking noises.

[StephenA]

There's a used harmonics balancer on ebay for $25.

[pannhead]

never buy a used harmonic balancer...they are extremely important which you already know because you're worried...as already stated if you bombed the engine you would probably hear it...if you're lucky a couple c-notes and two hours of your time and you're good to go....good luck ;)

[turbovair]

I'm with Pannhead on this one...new balancer only!

[ucdavis]

And I'm w/Turbo, you'll get noise from the busted HB that will likely obscure any additional damage noise up to the point the crank gives up the ghost, then you'll realllly know.
I'd R&R the HB & appurtenant stuff, then fire it up. If it hums right along you probably got it in time. You might want to put another 5000 or so on it B4 upping the boost just to be sure.

[StephenA]

Thanks for the warning on the used HB; makes sense not to fool with a used one. :D

[96turboSuburban]

Thanks Guys!
How's that bike running pannhead? You didn't put it away yet except to keep the ash from those nasty fires from clogging up the intakes!!!
OK, I'm gonna buy a new HB and pulley and belt and bolt 'er up and run her awhile to see if all is well. I've got calls in to parts houses now to get one.
I'll keep you guys posted on what happens.
Thanks!
Todd smile.gif

[96turboSuburban]

Update:
I bought a new HB from local chevy dealership for $110.00 cash.
I'll let you know how she runs when I put it on!
I'm optimistic tongue.gif
Todd

[pannhead]

96 TurboSuburban....bike is in the garage,well protected...fires,recall elections,earthquakes,weirdos,fruitcakes etc etc..this is CALIFORNIA, nothing phases me anymore :D ...good luck with the Burb

[jspringator]

Isn't the crank pully the same as the harmonic balancer? More Power had a post here earlier that has been deleted with a link suggesting that if the harmonic balancer was bad to replace the crank pully. What am I missing? Should they and the belt tensioner all be replaced at 150,000 miles? I am going top to the keys in December and I don't want any problems.

[pannhead]

the crank pulley is different than the harmonic balancer, yet the crank pulley does fit into the harmonic balancer...the problem with them is that the rubber starts to wear, then things go bad quickly....i had to change mine a couple months ago,easier than it looks....dealer wanted over $200....i got it thru NAPA for $70

[vernon]

Originally posted by James Springate:
Isn't the crank pully the same as the harmonic balancer? More Power had a post here earlier that has been deleted with a link suggesting that if the harmonic balancer was bad to replace the crank pully. What am I missing? Should they and the belt tensioner all be replaced at 150,000 miles? I am going top to the keys in December and I don't want any problems.

[vernon]

Greetings from Florida!
I too have a 1999 K2500 6.5 Diesel. Technically the Pulley bolts onto the Harmonic Balancer, but they are sold seperately. I just returned a few hours ago with a new Harmonic Balancer from "O'Reilly Auto Parts" and it was (surprisingly) $59.99.(they matched AutoZones price!)
Here are the manufacturers & part numbers for your Harmonic Balancer...
DORMAN #594037 $59-99.
Pioneer #3950 $79.-99.
BTW... Get A New Oil Seal (replace the one where the H-M slides into the Timing Chain Cover) they are only about $8.00, but well worth it!

Good Luck!
Vernon Sutton
Pensacola, Florida

[96turboSuburban]

Final Update:
All is good, tore down the pulley and HB and replaced both. The crank pulley was the one in the worst shape and I just decided to replace both as a pair. Thank God I didn't let it go long enough to crack the crankshaft!!!
Thanks to all on this thread and the forum in general!! There is a lot of great knowledge that is shared here and it shure helped me.
My pulley's rubber dampener was completely separated.
Pannhead, I'm glad you and your bike were spared!
Take care all.
Todd in Md. :cool: