Check your balencer

[allenhillview]

Got mine coming a cheap one at that but at least it want do damage for a while to come that wobble was driving me crazy at idle. Doorman , we'll see how long it last then buy another. Sharecropper , tell us how yours' goes (fuildamper)? Found OEM but it was 162.00 so if I were going that amount I'd get the Fluidamper

 

[allenhillview]

Finished Damper job today all went well. Yea.. Doorman product but my wobble is gone, it wasn't bad but a piece of mind and a new bolt , new crankshaft seal, and a timing cover seal inspection no leak there. Seen my wobble early on but this forum was a wake-up call. Thanks again

 

[cucv1833]

Just installed my new balancer. I changed it mainly because I had to change the front timing cover seal. All went well. But it took me most of the day.

Thanks to allthe info on this Thread

 

[HOWEY]

Is this wobble bad?

Have a leak from the frontof my 6.2, thinking its the timing cover seal i ordered one in, upon closer inspection i think the leak is a combination of this seal and the oil pan which appears to have no gasket but orange coloured sealant
Can you seal the oil pan with sealant alone??

After reading this thread i think ill order a new harmonic balancer, mine has a wobble, how bad? ill let you guys decide.............


[media]http://www.youtube.com/watch?v=YciE-0H2en8&feature=g-upl&context=G227e6f3AUAAAAAAAAAA[/media]

 

[trukhead]

Replace your dampener.

 

[biggestc69]

My boss bought his M1008 with 44,000 miles 2 years ago. Did some reading on here and saw this post, checked his balancer and it was really bad. Changed it out. He put about a thousand miles on it and pulling out of the drive way something let loose. I'm pretty sure its the crank. Who knows how long the balancer was bad before we got it. Time for an engine swap.

 

[K9Vic]

I just replaced the balancer on my M1031 as I was already there checking on a leaking water pump I thought. Turns out it was a loose bolt on the water pump from the previous owner not tightening it down correctly adjusting the power steering belt.

Anyways, this is something I pretty much do on any truck I get now as when I inspect them they are almost always going bad or already there. I have it down now that I can change one out in about 2 hours as that was my 4th one. I would suggest doing this on any old CUCV you get as after 25 years that rubber will likely be dried out.

So here is the M1031 balancer and you can see it is bad. Also the special home made tool to install the new balancer back on without pounding it back in risking damage.
.

 

[davesgmc]

the balanced portion of extewrnal balance on these units is not in the outer ring, it can come looser, fall completely off and it wont cause a broken crankshaft, no way no how. the balance portion of it is in the center part of the hub, and that cant move. the outer portion only takes out the harmonics vibraions of the crankshaft. sure you shboulod take a look at your balancer, if he rubber is getting rotted or the balancer wobbles at all, repalce it, bujt it alone wont cause an engine to break its crank. now the cast iron crank will break on its own, just because its a crap made product. adn if it was EVER rebuilt and turned by somone that didnt know crap aout them and didnt turn the proper radius in the shoulders of the crank then modify your bearings to fit, sure its gonna break, but ther are litterally thousands of these out there on the road working great with hundreds of thousandds of miles behind them, just drive it slow like its suppose to be,,,if you want a hot rod diesel,,,,put a detrot in it!

 

[Anubis8472]

the balanced portion of extewrnal balance on these units is not in the outer ring, it can come looser, fall completely off and it wont cause a broken crankshaft, no way no how. the balance portion of it is in the center part of the hub, and that cant move. the outer portion only takes out the harmonics vibraions of the crankshaft. sure you shboulod take a look at your balancer, if he rubber is getting rotted or the balancer wobbles at all, repalce it, bujt it alone wont cause an engine to break its crank. now the cast iron crank will break on its own, just because its a crap made product. adn if it was EVER rebuilt and turned by somone that didnt know crap aout them and didnt turn the proper radius in the shoulders of the crank then modify your bearings to fit, sure its gonna break, but ther are litterally thousands of these out there on the road working great with hundreds of thousandds of miles behind them, just drive it slow like its suppose to be,,,if you want a hot rod diesel,,,,put a detrot in it!

Uh .. you do know the 6.2 is a 'detroit' right?

The real reason the crankshafts snap is because the 6.2 was designed to use a forged crank, and as a cost saving measure GM went to cast iron.
The diesel stresses the cast crank, without the damper functioning properly those crank vibrations are much more damaging then they would be in another engine.

On a side note, has anyone come acrost an aftermarket forged crank?

 

[davesgmc]

far from a detriot in any realm, detroit gave advice on its design, and gm ignored it. a real detroit 2 stroke diesel is what i meant to say

 

[Keith_J]

Crankshafts are constantly accelerating and decelerating even when operating at constant speed. in a V8, there are 4 decelerations as the pistons on compression come to TDC, then 4 accelerations as the cylinders fire. Every revolution. In a gasoline engine with a high 10:1 compression ratio, this is quite minimal even at full throttle. At idle, it is nothing.

But diesels are different, the compression deceleration is GREATEST at idle because diesels don't have throttle plates so each compression is maximum, regardless of power output.

Since the crankshaft is connected to the transmission (torque converter) at the rear, the crankshaft experiences wind-up at the front from these accelerations and decelerations. The purpose of the damper is to reduce this wind-up as it stresses the crankshaft in what is termed cyclic fatigue. It does this by storing energy (torque) during crankshaft accelerations, returning the energy back to the crankshaft during decelerations. By reducing windup, the crankshaft is now stressed below the fatigue limit in torsion.

The rubber "spring" element is subject to normal deterioration from both environment (oxygen), use (fatigue). Replacing it every 10 years is cheap insurance on any diesel engine. On gasoline engines, they last much longer since they are stressed far less.

 

[Keith_J]

Cracks were showing on mine so I bought a new one. Made in Australia? Oh well, better than China.

 

[Lagers4myhead]

Ok here is the post you have all been waiting for......

BALANCER R&R on a M1009

First order is to get TM and get torque data

special tools needed

Have a prybar 18" and 24" would be good
15/16" socket
1/2 breaker bar or two and rachet
Torque wrench
2x4 and hammer
balancer puller


Park truck in area where it will be easy to crawl under and also get under hood....a stool or box helps....

Gain access by removing fan belts and then remove the 4 nuts (1/2") on the fan at the pully on water pump.
Then remove the fan shroud remember to pull all bolts from it.....2 on bottom and I think 6 on top(10mm) and the upper radiator hose is clamped (11mm or 12mm) to it as well...

Then crawled under and used a 18" prybar from harbor frieght....(by the way 4 pack on sale for 7.99) and using frame hole and timing mark on balancer held balancer still to remove 4 (15mm or 9/16") bolts from crank pulley I used 2 breaker bars and held one bolt and loosened others then used the prybar for last bolt...

Once pulley is removed.....install 2 of the pulley screws back in and hand tighten them down most of the way....then isnert prybar between them to hold balancer....(shown in picture below).... then using a 15/16" socket on a breaker bar remove the bolt and large washer from crank.....then remove the 2 pulley bolts and install puller.....

Remove balancer then using careful practice remove old woodriff key and replace with new... then place new balancer in place and slide on as far as you can by hand then using a 2x4 about 8" or a little longer and a hammer tap balancer down as far as you can.

Then install new bolt and thick washer and torque after insuring it is seated....

Then clean pulley off...the one I was doing had trash built up in it......that alone could cause problems on your pulleys...then installed everything in reverse order and remember to torque your bolts and if neccesaery use thread locker...blue is best if you ever want to remove it again...

Here are the pics to go with the procedure....

So if I understand this correctly I will need a new woodriff key and a new bolt and thick washer? Is this a easy to find item and are there certain ones that are better than others?

 

[Matt65]

So if I understand this correctly I will need a new woodriff key and a new bolt and thick washer? Is this a easy to find item and are there certain ones that are better than others?

Mine came with key, and hardware. Use the puller/install tool and torque wrench.

 

[SouthernSteel]

Part Number For us m1008 folks and Which harmonic balancer Fluid like new civilian 6.2s or like what the military put on it and price ,Thanks

 

[Keith_J]

My NAPA puller also doubles as an installer with the addition of a thrust bearing. Sounds odd but the puller's threads are the same as the crank bolt, the 1/2" hex head is smaller than the root of the threads so it sails clear of the threads.

Don't ask me of the thrust bearing, it is something I found and kept, thinking one day I might need it.

I should have done this at mkcoen's BUT I feared the failure of the harmonic damper.

IMHO, if the keys remain on the crank, leave them. Replacements are provided in case you lose the originals. If you install with an installing tool, the bolt should be fine for reuse, it is by no means torqued to yield, using it as a tool to pull the damper on can damage the threads. Applying antiseize to the threads can help.

 

[Terracoma]

Cracks were showing on mine so I bought a new one. Made in Australia? Oh well, better than China.

Purchased from NAPA?

I'd gladly take Australian-made.

 

[Keith_J]

Purchased from NAPA?

I'd gladly take Australian-made.

No, the Irish guy . I went to NAPA for some 3/8-16 TPI bolts, 1-1/2" long. They had nothing on hand.

I fear my local NAPA is going under. And the Irish superstore is far closer than the NAPA warehouse.

 

[MuleMac01]

on a side note I checked mine today... for a m1009 with 75k miles on it my blancer front ring looks ok... no cracks How do you inspect the back for cracks without taking it off? little angle mirror?

 

[Keith_J]

on a side note I checked mine today... for a m1009 with 75k miles on it my blancer front ring looks ok... no cracks How do you inspect the back for cracks without taking it off? little angle mirror?

Yes, and by feel. Inspecting all of it is difficult, the one on my 1031 was only cracked on 1/3rd of the circumference which is why I thought it was fine.