6.2 balancer/pulley

[Jcode]

I've noticed that my balancer has a slight wobble to it while idleing and the pulley has a very noticable wobble. Planning to change out both as PM. Should I go with a GM balancer and pulley or would napa be OK? Is there any difference in changing out a balancer on the 6.2 vs. a 5.7 gasser? Thanks.

[trbankii]

Definitely sounds like you need a new one. Another option is the FluiDampr: http://www.thedieselpage.com/features/fluidampr.htm

[DmaxMaverick]

If both are wobbling pretty good, be sure to inspect the crank stub real well. The pulley attaches to the solid center of the balancer, which is attached solid to the crank stub (no rubber interface). They should not wobble together.

Nothing special with the balancer/pulley replacement. About the same as the SBC's. You'll need the same type puller.

[Jcode]

DmaxMaverick: You have me worried now! Can the crank stub be replaced or is it basically the end of the crank itself? What do I need to look for when inspecting it?

I guess the only other possibility would be a loose or missing bolt (that connects the pulley to the balancer). Is there any rubber on the pulley? If the pulley and balancer are both mounted hard to the crank, shouldn't they both wobble with equal imbalance (the pulley wobbles way more than the balancer)? Thanks!

[DmaxMaverick]

Sorry to alarm you. Didn't mean to cause worry. Just a caution to check it. It's more likely there is no damage, but having a close look won't cost you anything. If you can't tell by looking, you'll know as soon as you remove the old balancer, or try to install the new. They don't fit loosely.

The pulley may or may not be the rubber isolated type, but it should be pretty obvious. My 85 isn't/wasn't, but I've seen some that are. I don't know if they were later replacements, or not. In any case, even if it had rubber and it's gone, it still shouldn't wobble because of missing rubber. It only cushions rotational forces. Like any pulley, it could be warped. The balancer outer ring can wobble when the rubber degrades, but the center hub should be bolted solid to the crank stub. The crank stub is the front end of the crank, and is not a separate part from the crank. If the balancer bolt loosened or went missing, the balancer hub can damage the stub. A few years ago, this happen on my 77 Mercedes Diesels. The crank stub was worn into a cone. I welded the balancer on the crank, and it lasted the remaining life of the engine (over 100K on the repair, about 450K on the engine).

[Jcode]

Appreciate the info. The reason I'm a little concerned is that I just bought this truck and I'm in the process of baselining it trying to figure out exactly what I have. The ONLY two things that would concern me is a cracked block or head that could cause problems or a bad crank, anything else is not a big deal. I gave a little more for it than I normally would have because it is rust free and looks to be in really good shape, etc. I'm not new to GM trucks/cars but I am a complete newbie to the 6.2 diesel. This is a great site and I do appreciate the help!

I checked the bolts to the pulley today and they are all there and all are tight. So I'll hope that it is just a warped pulley.

[Jcode]

How many GM versions are there of the rubber isolated 3 row type pulley? Is there any difference in the civvy 3 row version for A/C (GM part # 15592128) and the 3 row rubber isolated pulleys found on the 1985 and up cucv's (with extra alt belt)?

[john8662]

Just another addition, a rough idling engine due to some fuel system problem, etc. will also be visable by the wabble of the harmonic balancer, as it's absorbing the abnormality in the combustion process on that engine.

J

[Ebrown]

A few yrs ago my 6.2 started to make a funny claddering sould, so i took it to a diesel shop, after a few day they called me back and said that the crank is shot and that I will need to have the it rebuilt.... So I brought my k-5 home and parked it in the garage ( Drank a few cold one) and started it up slid under it with a flash light and started looking around and I saw a slight wobble in the crank pulleys.. Next day i went out to look into the problem with a clear head, I had removed all the belts slid back under the blazer and found that the rubber dampener pulley was shot.. I ordered a NOS from Boyce Equipment (Solid 3 row pulley).... So far I have had no problems with it

[JohnC]

... So far I have had no problems with it

Yeah, but what did you do about the broken crank? ;)

[Ebrown]

After inspection of the pull, we figured out that it wasn't a broken crank but the pulley with the rubber isolator was worn out and making the noise.

[Jcode]

Update- My truck has been on the back burner for several months while we've been renovating the house. I have been driving it a couple of times a month to keep the battery charged, etc, but not much time to work on it... Finally got around to changing out the balancer and pulley and that fixed my wobble problems. I went with the factory GM balancer and older style (non-rubber) pulley. The balancer has no signs of wobble at all now and the new pulley has a very slight, hardly noticable wobble, but it is 90% better than it was.

[chevytuff]

Alledgedly the Rubber Isolated Pulley's help increase belt life and reduce Shock load on the Accessories.

I scored a 1985 K10 Suburban with zero rust in pristine condition for 900.00 because the Previous Owner thought the Motor was junk because at idle the motor was knocking like someone was beating on a trash can with a sledgehammer. It went away when you reved it up which from previous experience I knew was an accessory problem. After being sticker shocked by the Factory replacement Vbelt pully (200+ Dollars) I sourced 2 metal ones from a local junk yard for 10 dollars. I replaced the Old Belts with Quality Gates belts and havent had a problem since.

Not Looking forward to buying that Pulley when I go Serpentine. Got all of the parts except for it. Wish they made an All metal serpentine version.

[vstech]

Happy Turkey day!

the factory price is a joke.
all parts houses stock OEM replacements for less than 75.00
Napa was 65.00 for my new serpentine replacement pulley.