I know very little about these, I just know my truck is very "rattly" sounding lately at idle and the rattle seems to go away when driving. A friend of mine suggested looking at the Harmonic Balancer, so I took this video. Could someone tell me if its normal for the pulley to move so much before it moves the harmonic balancer? Here's my video that I shot a few minutes ago... http://www.youtube.com/watch?v=W5vsfBcufnU

Any thoughts?

Thanks,
Matt

The problem looks to be with the front pulley that bolts up to the harmonic balancer. The pulley center is isolated from the outer with rubber and 4 supports and it looks like yours failed. i would get a new one asap

Nah that'll buff out.... :D :D

seriously though, I would replace that before running the engine again, or you might find yourself with two crank shafts

No it's not normal, but mine did the same thing two different times. Once the pulley, which is bolted to the harmonic balancer, broke, and another time the harmonic balancer itself came apart.

I'd say pull it apart and replace either the pulley or the harmonic balancer itself. NOt to try to scare you, but I believe letting this go could result in a broken crank.

Good luck. I like my 1993 6.5!

Yes, looks like the rubber isolated crank pulley is certainly bad. It's designed to lessen/limit how much tortional vibration gets transmitted to the belt driven accessories.

The harmonic balancer is just behind that pulley & should also be checked when you replace the belt pulley

The problem looks to be with the front pulley that bolts up to the harmonic balancer. The pulley center is isolated from the outer with rubber and 4 supports and it looks like yours failed. i would get a new one asap

Thanks, the pulley appears to have put "grooves" into what I think is the Harmonic Balancer. It seems to move the balancer only when the pulley spins enough to hit the bolts on the balancer. My question now is this: Do I need both a Harmonic Balancer and a pulley? Any suggested part numbers? I was a little confused looking at these online as my pulley didn't match any of the pictures I saw.

Thanks again
Matt

Becareful of what crank pully you get, there have been a few guys who have had problems with their pullies right off of the bat. (Napa is the one that comes to mind)

My guess is that it is just the pulley take the belt off and the 4 bolts and it will come right off then you can take a look at the Harmonic balancer behind it they are two separate pieces.

Well here are some pics of how the setup works hope this helps the pulley is on the left and the harmonic balancer is on the right.

I think this would be a GREAT video to add to the FAQ page somewhere. There are a tone of people that ask if their balancer needs to be replaced and I think this is a great thread to help people out on what to look/listen for.

Well here are some pics of how the setup works hope this helps the pulley is on the left and the harmonic balancer is on the right.

My pulley just has the wheel spokes, what's all that black stuff in the middle of your pulley? Rubber? :) Mine seems to be missing that...

Matt

Yep it is rubber I think that missing the rubber is not a good thing and why yours freewheels like it does, the rubber holds things together as best as it can :-)

thats what causes it to blow the #2 main, mine has done it twice and i just looked at a 97 on friday that did the same thing(#2 main) and its pulley had the rubber spinning so the outer part was actually slapping grooves in the arms from the 4 bolts

thats what causes it to blow the #2 main, mine has done it twice and i just looked at a 97 on friday that did the same thing(#2 main) and its pulley had the rubber spinning so the outer part was actually slapping grooves in the arms from the 4 bolts

Is "#2 Main" a crank bearing that goes out when this happens? If so, how would I know if it too is shot?

How can I tell if my harmonic balancer is shot too? The pulley has a "tab" that is moving in a groove on the harmonic balancer...I think you can see it in the video. Not sure if that groove is suppose to be there or if this pulley did that.

Anyone have a good suggestion on brand/part #'s I should get to replace the pulley, and possibly the harmonic balancer? Salvage yard ones any good, and if so could I get one off a 2004 truck? See http://cgi.ebay.com/ebaymotors/Harmonic-Balancer-w-Crank-Pulley-04-GM-6-5L-Engine_W0QQcmdZViewItemQQ_trkparmsZ66Q3a1Q7c65Q3a1 5Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a0Q7c293Q3a2Q7c294Q 3a25QQ_trksidZp3286Q2ec0Q2em14QQhashZitem4397dd8bc cQQitemZ290310687692QQptZMotorsQ5fCarQ5fTruckQ5fPa rtsQ5fAccessories

Thanks again guys
Matt

Since your going to be in there. I'd change the Harmonic Balancer as well. If the rubber in the crank pulley failed the rubber in the HB can't be much better i'd say.

Torque specs are as follows.

Harmonic Balancer Bolt to Crankshaft - 200 Ft Lbs
Crank pulley to Harmonic balancer(4 15mm head bolts) - 37 Ft Lbs.

Is "#2 Main" a crank bearing that goes out when this happens? If so, how would I know if it too is shot?

How can I tell if my harmonic balancer is shot too? The pulley has a "tab" that is moving in a groove on the harmonic balancer...I think you can see it in the video. Not sure if that groove is suppose to be there or if this pulley did that.

Anyone have a good suggestion on brand/part #'s I should get to replace the pulley, and possibly the harmonic balancer? Salvage yard ones any good, and if so could I get one off a 2004 truck? See http://cgi.ebay.com/ebaymotors/Harmonic-Balancer-w-Crank-Pulley-04-GM-6-5L-Engine_W0QQcmdZViewItemQQ_trkparmsZ66Q3a1Q7c65Q3a1 5Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a0Q7c293Q3a2Q7c294Q 3a25QQ_trksidZp3286Q2ec0Q2em14QQhashZitem4397dd8bc cQQitemZ290310687692QQptZMotorsQ5fCarQ5fTruckQ5fPa rtsQ5fAccessories

Thanks again guys
Matt


The pulley should not move like it does in your video. The rubber in the pulley is to absorb shock and not transfer it to the accessories.

Don't buy a used one. Not a good idea imo. I paid $175 for both the crank pulley and the balancer when i changed them on my truck.

the bearing isn't what fails in the #2 main, it's where the crankshaft tends to break in 1/2 when the balancer goes bad. . I'd change both the pulley and the balancer before running the truck again.

The pulley should not move like it does in your video. The rubber in the pulley is to absorb shock and not transfer it to the accessories.

Don't buy a used one. Not a good idea imo. I paid $175 for both the crank pulley and the balancer when i changed them on my truck.

the bearing isn't what fails in the #2 main, it's where the crankshaft tends to break in 1/2 when the balancer goes bad. . I'd change both the pulley and the balancer before running the truck again.

Thanks. I'll buy new. I just found the part numbers in another thread so I think I'll be all set now. Here's what I'll buy (new):

-DORMAN Part # 594037 {Original Equipment Solutions #12557345}
Pulley

-DORMAN Part # 594170 {Original Equipment Solutions #10154688}
Balancer


Thanks again everyone, I'll post a followup when its done and let you know how it went. My truck will stay parked until then... :)

Matt

the #2 main fails first before the crank breaks, i drove for 2 weeks with the broken main cap, its when you get on it once it already had the cap failure that the crank breaks.

the first telltale sign is the oil pressure drops off instantly when you let off the accelerator and jumps up instantly when you touch the throttle, when you let off and the oil is hot it will dip below 20psi and eventually plunge to 0 for a second and then back to 20 just like it had run out of oil but is actually the crank flexing far enough to lose oil pressure to the top end because it is all coming out that main journal.

Becareful of what crank pully you get, there have been a few guys who have had problems with their pullies right off of the bat. (Napa is the one that comes to mind)

Yep thats me, put my original back on after my 1 month old napa did exactly what yours does in the video, it wasn't easy to move it, but i could w/2 ahnds and it should be bound to that rubber.

It created a clunk at turn off, and a nasty rattle at idle, sounded like piece of plastic grill flapping with ear on front of truck.

Taking belt off, hid the problem, unloaded it didn't rattle, so i chased around my other pulleys, eliminating my vacuum pump and replacing p/s pump, it was duringvb the p/s r&r i realized my crank pulley, which was new, was junk.

NAPA sold me a part that said CHINA right on it.

I put my 12 year old DELCO original back in. and noise and clunk went away.

Lesson learned, if its not broke, don't fix it i guess. Not with crap parts. I'm hesitant to buy any part nowadays...

Thanks for the Video. I haven't been here for two years, as I haven't been driving my Suburban much. Last week it started making the "rattle" noise like yours. Did you replace your parts yet? Fix the "rattle"? Are Dorman good US parts? Find a good price on quality non-china parts?

Could always go to GMpartdirect.com?

Okay, did some research on the above site for those wanting GM approved parts.

Pulley $177.32

Ballancer $84.46

Pulley sounds a little pricey to me, but I never had to replace mine on Ole Red.

Okay, did some research on the above site for those wanting GM approved parts.

Pulley $177.32

Ballancer $84.46

Pulley sounds a little pricey to me, but I never had to replace mine on Ole Red.

I found the opposite here in B.C. Tony, the balancer at the dealer was $220 and the pulley at the local parts store was $92. I would also suggest for an extra $ 12 to replace the front crank seal. Took 5 minutes more and the new balancer and seal surfaces should prevent any leaks for a while!

Well I ordered all my parts (crank seal, harmonic balancer, and crank pulley) from rockauto and took it the garage where they were suppose to put in all the parts I gave them while they had the serp belt off. They said they inspected my current balancer and it was fine so they just put the crank pulley on and a new serp belt. That has taken away the knocking sound I had, but now I'm stuck with an extra harmonic balancer and crank seal if someone can use them let me know as rockauto wants to charge me a restocking fee if I send them back.

Matt

The problem looks to be with the front pulley that bolts up to the harmonic balancer. The pulley center is isolated from the outer with rubber and 4 supports and it looks like yours failed. i would get a new one asap


. Are you surprised with your results, or dissapointed they ddint' take the balancer out? I'd be a little peeved if they didn't call me first, They were in there that deep would have taken them another 30 minutes tops. Now your stuck with a replacement balancer and an old one on your truck that has rubber thats 15 years or so old. (Remember what the rubber did on your crank pulley). It wont last forever, and can take out the crank when it fails.

Unless they called you to ask if you wanted to not install the HB. I'd make them put it on for no charge, as you now have to bring your vehicle back is costing you money.

In all reality, a garage with a mechanic who just did 90% of that job could probably bang out the HB in an hour.

I was surprised he didn't put them in, I bought them for him to install and am still not sure why he didn't. Once I found out though it was too late to do anything since he already had the crank pulley back on and the serp belt on. I thought it would be pretty easy for him to have done though while he had it apart. He seemed to think the balancer still looked good and that I didn't need it. My truck did quiet down quite a bit with the new crank pulley.

Matt

Well... if it looked good or not its still 50k miles over its expected miles.... Just buy/rent a HB puller for 15bux and do it yourself.

I've replaced replaced the crank pulley and harmonic balancer twice since I've had my Burb. I bought both from Napa and both ended up in the trash (Korean made). Since then I have always gone OEM even if it means paying dealship prices.

Is the crank seal the same thing as the timing cover seal? Part# 3945 at RockAuto?