Crank pulley play: how much is acceptable?

[cscmc1]

After a good bit of searching, I see lots of mention of bad harmonic balancers and some stories about bent crank pulleys, but I'm wondering whether my crank "wobble" is enough to worry about, and I have yet to find a thread that addresses this matter.

In short, I have been looking my M1009 over just to stay ahead of any problems that may arise, and have looked at the balancer (and marked it, to keep an eye on it). I don't see any issues with it at the moment, but with the engine running, when viewed from the side, there is some VERY slight wobble perceptible on the crank pulley/balancer assembly. I'm not sure how I could even safely measure this play; I can just detect it when watching very closely.

Anyone else noticed the same thing? Is this something to worry about? Thanks in advance, folks!

 

[Tanner]

You won't be able to visibly discern the impending destruction of a harmonic balancer. When in doubt, replace it.

'Tanner'

 

[cscmc1]

Thanks, Tanner -- so no play at all, however minute, is acceptable, huh? Better set aside a Saturday to tear things apart!

 

[197thhhc]

The balancers wont run perfectly true but close. With this being a known issue I think setting aside a Saturday is a good idea.

 

[cscmc1]

Thanks, fellas. I went out and crawled under the truck while she was running, and am now wondering whether maybe I have a bent crank pulley. The balancer seems to have essentially no wobble, while the pulley has a little bit.

I tried taking video, which turned out somewhat iffy. In any case, I recorded from both top and bottom, and there are moments when the camera actually manages to auto-focus and give the viewer an idea of what I'm talking about. Any comments are certainly welcome; I appreciate the advice, and plan to replace the balancer even though it has no pay at all when checked by hand.

Link to video: [media]http://www.youtube.com/watch?v=nmRpW-zFCZ4[/media]

 

[Keith_J]

Video is private.

Once you pull the pulley, you will see why it can run off center, it is bolted to the damper hub with 4 bolts. If you loosen the bolts with belt tension, it can pull the pulley off axis. Or, in other words, it can be slightly adjusted.

The v-belt pulley is not part of the damping assembly. Damping happens with the outer ring on the balancer and its attachment to the hub with the rubber ring. The rubber ring is what fails, either use a mirror and light or feel the rubber ring, any breaks or lost material is suspect and these will be found before the outer ring slips. Also, the rubber is the spring portion of the damper, rubber hardens as it ages, increasing the spring rate which can raise the critical frequency of the damper.

$62 is cheap insurance against a broken crank. Yes, the cranks are nodular cast iron. Normally, this is quite tough compared to gray or white cast irons. The cranks break from torsional fatigue and nearly always, that is due to an old and failed harmonic damper. Diesel engines with their high compression ratios and clatter place much greater demands on crankshaft harmonic dampers.

 

[cscmc1]

Thanks, Keith_J -- and sorry for the video snafu. Should be available now.

Yes, in any case, I plan to swap the balancer out. I had scribed lines on it in white grease pencil a few weeks ago, and the outer ring has not migrated any (yet). It's quite hard, though, and I suspect it's the original balancer. Can't hurt to pull it and replace, though I have yet to detect any cracks. I am hoping one of the local parts houses will have a puller/installer loaner tool.

 

[cscmc1]

Just to update -- I FINALLY got a chance to R&R my balancer, and the play in the pulley is gone. I have yet to drive it, but at idle, it looks to be smooth as can be. I discovered a little bit of gunk (perhaps some kind of adhesive residue) on the mating face of the crank pulley, which I cleaned thoroughly, so that may have had some effect on wobble, too. In any case, the balancer replacement wasn't bad at all, and it's nice to know that that's one less "catastrophic failure" item to worry about.

I need to find the correct size starter bracket nut and get that installed now, and replace the U-joints (for good measure). It's sure nice to have that balancer done, though. Finding something to press it on took far too long, but it's done, finally! Thanks again to all those who offered advice.

 

[CycleJay]

Cscmc1,

I have noticed mine is doing just about the same thing, but it does not wobble as much
as yours. It is very minute and barely perceptiable on mine.

But I am going to replace the harmonic balancers asap anyway, just for peace of mind.

How long did it take you to do? And how difficult would it be for someone that can do
the work, but does not work on engines on a regular basis?

Also, when you get a new balancer, does it come with that rubber outer ring?
And would it hurt to replace the crank pulley, anyway, since it would be off?

One more thing, do you have an auto part store part number for the harmonic balancer?

I know Napa has one for the civy "C" code 6.2L diesel engine, but these are "J" code
engines... So would there be a difference?

Thank you, good day,

CJ

 

[cscmc1]

Hey CJ -- I am traveling at the moment, so no access to my receipt for a part #, but I went with the OReilly Auto Parts balancer, which is made in Australia. It appears to be a very nice part and was only about $60. I just told them I needed a balancer for an '85 Blazer with the 6.2 and it was the correct part. Search a bit here and you'll find lots of posts with part #s.

It wasn't a bad job at all once I gathered all the tools necessary. You can find a puller easily enough, but the installation tool just wasn't available here locally for rent, so I made a tool. Search my other threads for a description of that tool, and you'll find the part # for an inexpensive pre-made tool that would have worked even better. Get all those things gathered, and you ought to be able to get it pulled and replaced in an afternoon. It's really not bad! Just take your time and resist taking shortcuts; you don't want to damage the threads in the end of the crank!

As for the pulley itself, I considered replacing mine, but once it was off, I was able to check it better and it appeared to be true and in very nice shape once cleaned up. I didn't bother to replace it.

Sorry I can't be more specific, but I'm out of town and just don't have my thoughts together right now. Good luck with the job -- I am sure you can do it -- and feel free to follow up here if you need more advice. I'll check back in once I get home!

 

[Keith_J]

I know it is going to another store to get the tool...NAPA sells a KD Tool puller which works great for both pulling and installing the harmonic damper. The pulling is easy enough to understand with the directions supplied, just use the correct bolts and it will eventually pull. You have to fight it all the way, no space to use an impact wrench but an air ratchet might work.


Now, for the installing with this KD Tool puller, #2291. The puller shaft has the SAME THREADS as the damper bolt, the hex head is machined down from this threaded shaft. It will thread in BACKWARDS into the crank. Slip the new damper on the crank and align the key to keyway. Now using the fat washer that secured the old damper, thread the puller's shaft into the crank, hex first. This means the ball joint head is sticking out, no biggie. Get at least 4 turns into the crank or until it won't go anymore. Now, turn the puller body down against the washer and damper. Using a large adjustable wrench, continue to turn the puller body as a nut against the washer and damper, forcing it on.


I've used this puller on many crankshaft pulleys, lawn mower engine pulleys and steering wheels. That is works for both processes makes it perfect for the CUCV owner.

I'm replying to all threads on the harmonic damper just because it is economical and downright useful. 2 CUCV dampers replaced without issue.

 

[southdave]

I can't tell from the vid. but onmy 1009 had one those harmonic type crank pulleys how it there I don't know but it was bad i can post pic tomorrow if needed

 

[CycleJay]

Hi guys,

Thank you for all the information. It is all duly noted. I will see what I can do in my case.
And git-er-done one way or another, when I get a balancer.

Any more advice? Feel free to share.. If not, that is okay too..

Good night...

 

[Keith_J]

The harmonic balancer is PRESS FIT on the crankshaft. Interference fit, it will fight you both ways. Use your muscles and a tool. KD2291

 

[cucv1833]

Hi guys,

Thank you for all the information. It is all duly noted. I will see what I can do in my case.
And git-er-done one way or another, when I get a balancer.

Any more advice? Feel free to share.. If not, that is okay too..

Good night...

CJ

Just read through this thread a few times. Alot of info is there. Part#'s, pullers, ect.
http://www.steelsoldiers.com/cucv/44202-check-your-balencer.html?highlight=harmonic+balencer

I used that thread as a guide and bought the Dorman H-balancer and a puller from O'riellys and front crankcase oil seal for under $100. It was my first time doing this and it went smooth. Just took me longer than most people said.

 

[CycleJay]

Cucv1833,

Hello..

I just called oreilly's and ordered the balancer.. I pick it up tomorrow.
Then I will do what I can to get it installed... Git er Done.

Do you have the part # for the crankcase oil seal? I cannot find it on oreilly's website.

Thanks...

 

[cucv1833]

Cucv1833,

Hello..

I just called oreilly's and ordered the balancer.. I pick it up tomorrow.
Then I will do what I can to get it installed... Git er Done.

Do you have the part # for the crankcase oil seal? I cannot find it on oreilly's website.

Thanks...

CJ
After a quick and easy search heres a thread with all the part #s you need on page-2
and some instructions on how to install the seal.
http://www.steelsoldiers.com/cucv/66270-harmonic-balancer-2.html

Good luck.

 

[CycleJay]

Cucv1833,

Thank you for the reply and information.
I will get an oil seal when I pick up the balancer, since they are cheap,
and should be done since the balancer is being replaced anyway.

I will git er done one way or another... Have a good one.



I have searched that thread, and still cannot find/see a part number for that $3.00 oil seal...

Anyone happen to know a part number for the oil seal that should be replaced,
when replacing the harmonic balancer?

Thank you...

 

[cscmc1]

See post #15 here:

http://www.steelsoldiers.com/cucv/66270-harmonic-balancer-2.html

My local O'Reilly's had it in stock when I bought my balancer.

 

[CycleJay]

Cscmc1,

Okay, got it now. I need a timing cover seal... Why did'nt you guys just say so.. LOL...
Also, it is not a $3.00 part, it is more like $12.00-$14.00...

I will be sure to get one when I get the balancer...

Thanks for the reference to the part #'s... I guess I will go to napa or oreilly's for a Dorman...

night...