How do you torque the crank bolt properly?

Edis06

Active member
104
38
28
Location
Florida
well, at this point you really only have 2-3 options
find or make a tool to hold the crank in order to achieve your 200 ft lbs. of torque and give it another try
or
get a new crankshaft

lot of dynamics at play right there. torsional, vibrational, heat, etc. it's a 6200 cc beast that's propelling a 5-6000 pound machine and turning a bunch or accessories. the keyway and key can't have any slop at all
You are 100% correct.

That's why that key is strictly for alignment. No way on this earth will a little key or a 1/4" groove hold that kind of force. It's all in the bolt.

After the keyway gets rewelded, I am installing a new OEM damper (again). I just purchased a right angle impact wrench because my real big one won't fit. The right angle wrench isn't made for heavy torque, but you can turn it as it impacts, unlike the guns, which I think will help. I am going to lock the flywheel somehow, or at least try. This will hopefully get me to the 200 ft. lbs. I need to keep it secure. This fix, if all goes as planned, should hold it, or at least hopefully until I find an engine installer.

If this works, or I even find a creative way to lock that crank, I will share it on the forum immediately. This is the first time I've been stumped when repairing an engine.
 

Milcommoguy

Well-known member
862
338
63
Location
Rosamond, CA
This has been one crazy thread. Like many, I have installed and removed a few balancer's. Google and Utube it. There are some tricks, tools and techniques... and some right in line with this thread and some well... Welding and glue... Not so sure that's the answer. It's all about the numbers inside and outside dimensions. If it 's been spun up and torn up... there a big problem. Press fit is the holding force, keyway a guide or indexing and that big bolt and the thick washer just hold it on. Even without the bolt , IMO it would be a hell of a trick for it to just pop off. Anything is possible I guess.

My 2 cents, something else is going. Show some good pictures of the crank and carnage.

This I got to see, CAMO
 

Edis06

Active member
104
38
28
Location
Florida
The welding and glue have nothing to do with the balancer. I got the trademark broken keyway (also all over internet) so I'm looking at options to fix it either permanently or at least until I get a new engine. The steel paste didn't work, nor did the welding of the balancer to the crank, but then again the bolt came loose. I'm sure we all agree the if you remove your crank bolt on any car, especially a big diesel, you can kiss your keyway goodbye.

What's different this time:

1. There is a GM recall of the crank bolt replacing the 8.8 to the 10.9, due to the issues I am having, verbatim. As expected, mine had the original 8.8 bolt. I did replace it with a custom 10.9 but it was not the right length nor the right texture. I have the OEM bolt now.
2. There is also a recall of the crank washer. The recall calls for a stiffer one, however I cannot find them. The original still works, so hopefully that will suffice.
3. When my last balancer failed, the bolt was hand tight after a week of driving and yes, the balancer spun slightly. The GM manuals say specifically you CANNOT reuse the balancers or the bolt. The OEM balancers have an extra "layer" of metal that allows them to fit snug in the inside of the tube. Once it is removed, or if it spins due to a bad keyway, it will no longer fit to spec. I inspected my new one and this is correct. See pics attached.
4. I purchased a right angle torque/impact wrench. I will be using this to install the bolt which gives me leverage and also has the impact which moves the bolt easier without affecting shaft rotation. We'll see if this works.

Unfortunately, my welder is sick so he keeps postponing the welding work. If he can't come tonight, I am repairing the keyway with a higher temp steel putty the reinstalling with a better torque spec and correct bolt. Otherwise, he will fill the hole in the crank with a tig weld then I will grind to perfection with my dremel.
 

Attachments

TOBASH

Father, Surgeon, Cantankerous Grouch
Steel Soldiers Supporter
1,680
372
83
Location
Brooklyn, NY
Please please please measure the hole/orifice in the balancer for me.
 

Edis06

Active member
104
38
28
Location
Florida
Also, that area of "roughness" inside consists of small lateral lines designed to collapse and grip as the installer pushes the balancer on the shaft. That reduces the internal diameter a bit. With that, I can totally see why they say you can't re-use a balancer.
 

Action

Well-known member
2,247
162
63
Location
East Tennessee
I measured from the end of the tape measure as well as from the 2 so you can get an accurate read. Not sure if a tape measure is accurate enough for your needs though.
It looks like you are not measuring the widest part of the hole. The distance from the top edge of your tape measure to the top of the hole is smaller than the distance from the top of the tape measure to the bottom of the hole. I wouldn't think the angle matters, because the tape measure is in the same plane as the surface of the hole.
 

Edis06

Active member
104
38
28
Location
Florida
OK, I installed a new harmonic balancer and OEM bolt on Saturday. As expected, the new balancer was TIGHT, TIGHT, TIGHT. Even with an installer, you have to strong arm it so there's no way the crank is narrowed down. I also followed instructions on the TSB for the install - they said to secure it with LOCTITE 272 on the haft behind the keyway and torque to 200 ft./lbs., securing the bolt with Loctite blue.

Most importantly, before the install, I had a very good welder tig weld in a new keyway. After hours of upside down welding, I trimmed it up and you literally couldn't tell the difference between the old metal and the new. The new key was installed and it all fit like new. Remember, up until now I was using steel putty. Simply didn't work.

In order to torque it, I did my best. I started with a ratchet, then used a right-angle impact at 180ft/lbs. Then used an extension and held the balancer with an oil filter remover with teeth. It's gotta be at over 200 now. Time will tell.

I drove it about 100 mile so far and it again runs like new.

This morning I took it to get one of my starter bolts drilled out and the owner of the shop finds this a common issue on GM diesels. He actually showed me an aftemarket bolt with teeth and an attachment which expands and connects to the pulley holes to secure the bolt to the pulley.
 

Milcommoguy

Well-known member
862
338
63
Location
Rosamond, CA
IMO... the fix here was a new balancer. If I follow correctly, the on and off, back and forth was becoming a problem. Sure it could work in some cases... if lucky.

And to add, something to check on these old engines.

Smooth running and balanced, CAMO
 

Edis06

Active member
104
38
28
Location
Florida
IMO... the fix here was a new balancer. If I follow correctly, the on and off, back and forth was becoming a problem. Sure it could work in some cases... if lucky.

And to add, something to check on these old engines.

Smooth running and balanced, CAMO
This is my second replacement, totaling 3 new balancers. The problem was the broken keyway and old 8.8 bolt. Hopefully I have it torqued down enough!

I also learned that you CANNOT reuse a balancer. Once removed the grooved surface is designed to distort as its pressed onto the shaft. You can clearly feel the difference between mounting the old (but only 3 weeks old) balancer fitment and a new in box unit.
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks