Could it be harmonic balancer??

[jessejane]

About a month ago my suburban started to feel like the motor mounts were loose or broken. A slight shake when she is idol or running, more so on the idling part.

Now I will not drive her... the engine is shaking much worse and I fear that it is my harmonic balancer. And yes, it is slightly louder, but the shake is more worrisome than the noise.
I do not see any visible 'wobble' coming from the balancer... but I did slide my camera down the best I could and snapped a few shots of it.

Take a look and see what you think... hubby says he sees slight separation of the rubber... the other BIG concern I have is that I DO NOT SEE the middle bolt!! Is is suppose to be visible or is it far back in that deep dark hole???

I will begin the task of taking apart the front end of the beast... but wanted a little input or suggestions of what y'all may think.

Also a note... the dealership had 'tightened' the harmonic balancer about 9 months ago or so... unfortunately, they are now closed down!! Yet, another victim of the failing economy... *sigh*

Sorry for the pic sizing... i resized like the other two and they still come out large :mad2:... and I do not know how to post pics with the popup screen like some of the other posters. Love that!

 

[Mudbath]

Rubber from those pictures doesn't look too bad. Try taking the alternator belt off and starting to see if noise or vibration is gone. Maybe something else like the vacuum pump or tensioner.

P.S. welcome to the site.:smile5:

 

[Matt Bachand]

Look at odlaw's garage for pictures of HB I believe there are af ew blind holes in it. I may be wrong. Defanately take the belt off and see if the noise follows or not. Also with it off double check your crank pulley as from that vague picture the bolts don't look quite centered, meaning the rubber may have let go. Or may not have.


How many miles on your rig? HB should be replaced every 100k they say, if it hasn't been changed yet, should replace it regardless.

Odlaw's garage has some great pictures of his recent HB r&r.

 

[qwomack]

You aren't looking at the harmonic balancer, you are looking at the serpentine pulley. Take the 4 bolts (15MM) off and the pulley will fall off in your hand. Then you will see the harmonic balancer and the "missing" center bolt. That is where you want to look for rubber separating. Let us know what you find.

 

[Matt Bachand]

Great call Quomack... true on all aspects.

 

[jessejane]

Thanks guys for all the great info... I will hopefully be able to dig into this tomorrow... *said with tons of enthusiasm*

I Mudbath & Matt... I will be doing that test first and will post my results! And I went to Odlaw's garage... that helps a lot... though I am not sure if I will be as lucky as him in getting the impact between the radiator and the hb... Hope so!

Thanks Quint for the term fix there... I need it.
though I AM a chick and most of what I do ends up being "you know.. that thing that is near the hose that has the clamp thingy-ma-bob that spins when you start it"... haha
But I'd like to think I can hold my own

Any ways... thanks again guys for the warm welcome and I will be back with hopefully the 'fix'... jj

 

[jessejane]

Oh... and the milage is 170K!

 

[qwomack]

You are welcome, JJ. Don't sweat the "chick" thing. I have met plenty of chicks that are more than handy around diesel engines. We even have our very own Missy Good Wench that is in the process of rebuilding her 6.5 as we write. Hang around here for a little bit and we'll have talking and acting like a pro.

Welcome aboard.

 

[Odlaw]

Your dampener pulley doesn't look real bad but for less than $80.00 I would replace it....along with the HB.
You can see the back of the HB by crawling under the truck and removing the skid plate - if you see rubber bulging out around the two pieces I would replace it.

Oh, and welcome aboard.

I guess I'll have to stop saying things like "thanks guys, and gal" hafta change that to "guys and gals" now that you females are representing in full force.....well, more than one anyway.

 

[Missy Good Wench]

Yessssss for sure. Remove the serp belt and see whats up down yonder.

Make sure the pulley's outer ring does not move or rock back and forth.

The serp pulleys have a bearing in the center that pilots the hub and the rubber allows the unit to flex and to damp the sharp power pulses of the diesel so the belt and accessories dont get flogged to death.

If removing the belt and running the engine stops the Bad vibes then you need to look things over well down there.

Keep us posted

Missy Good Wench

 

[jessejane]

Howdy Odlaw & Missy...

Thanks for all the add's of things to watch for... every little bit helps.

Yes, my hubby and I agree, we will be replacing just about anything we are taking off... no sense in put old back on when you get her down that far! Probably go for replacing the timing chain as well. Especially since we do not have the complete history of the truck... bought at 130k.

Missy:
I see we are fellow commercial girlies... I hold my CDL as well. I don't drive as much as used to. We own a 2 Freighliners at this point but will be getting rid of one, the slow economy.. grrr. I will never give up my CDL though!

And Odlaw... Please DO NOT stop with the 'hey guys'... I am not politically correct by all means... haha...
It is Mankind, the HuMan race, and I still call it a Manhole because I had to work in one and it is not a place I wanna be... you men can keep it! haha

Cheers... jj

 

[bk95td]

The timing chains don't usually get very sloppy untill 250,000 or so. It's a very big job to replace them. The whole front of the engine has to come off. If you do decide to do the timing chain the aluminum timing cover should be removed and resealed with a gasket or anarobic sealer or both. When the water pump is removed it sometimes breaks the seal between the block and the timing cover[guess how I know that]. I reccomend the cloyes timing chain and gears. They are much tighter than melling. And welcome aboard.

 

[Matt Bachand]

The timing chains don't usually get very sloppy untill 250,000 or so. It's a very big job to replace them. The whole front of the engine has to come off. If you do decide to do the timing chain the aluminum timing cover should be removed and resealed with a gasket or anarobic sealer or both. When the water pump is removed it sometimes breaks the seal between the block and the timing cover[guess how I know that]. I reccomend the cloyes timing chain and gears. They are much tighter than melling. And welcome aboard.

you'd be the one to know with that fleet of 6.5's.. I wont worry about mine until 250ish then. Unless waterpump goes??

 

[Missy Good Wench]

J J
I been jamin gears now for almost 20 years.
I run an 8 axle transfer dump truck (105500#)
Big yellow motor under the hood of the 95 Western Star with an 18 speed Ranger backing it up.

On my second tranny now at near 600K on the rig.

Been pretty good to me for sure.

Getting tired of the double clutching boots and the chain drive wallet though

Best

MGW

 

[Detroit Dan]

Hey, I'm glad this thread popped up, I've been wondering about mine lately. I seem to have a little vibration at idle but a tremendous one at about 2000 rpms, it shakes my dashboard. I was thinking my new downpipe might be touching somewhere, or the motor mounts going, but the HB is probably more likely. I sometimes notice a quick ratheting sound when I shut it off, which I seem to remember hearing years ago could be the HB.
Thanks for the info, I'm going to climb under there and take a look at the back of it tomorrow. Maybe I'll try the serp belt thing too, apparently it's okay to drive it with the belt off?
Lastly, I still have my vacuum pump in place, is that like a ticking time bomb that should be disabled?

 

[NVW]

Sounds like it could be your drive pulley in front of the HB. Remove the belt and grab the pulley and rotate back and forth. It should be tight. I wouldn't drive it without the belt, a short idle period watching the temps would be OK. Get the shorter belt and scrap the vac pump, one less thing to worry about.
Your down pipe could be touching the frame or the front mount, mine touches the front mount and vibrates at 1500 rpm.

Leo

 

[Matt Bachand]

Yeah, no belt = no water pump circulation, concentrated hotspots inside engine, safe for fast idle checks, not to drive IMO.

I notice my engine seems to get alot louder betwen 2200-2500 then quiets down. I think thats the entire reason I like to drive 2,000 rpm. My new tires made it go away i thought, but I noticed it again after I fixed my VSSB, (boggles my head).... Its hard to explain, no vibration, sounds like a ton more air passing through it, but it goes away at higher rpm w/out shift. Hoping a fluidampr will make that history....

 

[Detroit Dan]

Well, I'm still going to check it but I'm leaning towards it being driveline related. If I put it in neutral and coast at idle it still does it, so it's speed-related not rpm related. It actually seems to have gotten worse since I replaced the rear u-joint. I probably bent the driveshaft again.

 

[96 OILBURNER]

Dan, you may want to check you center support bearing, if you have one. The rubber that the bearing is suspended in gets weak and can cause a vibration at speed.

 

[jessejane]

OK.... so every thing from post# 15 is for Detroit Dan.... Not sure but if a mediator can separate these posts??
Thanks... jj