Write-Up: Removing the Crank Pulley/Harmonic Balancer

LARRY70GS wrote:

albertj wrote:

LARRY70GS wrote:

I have never used thread locker on a crank bolt.  Just torqued it to spec.

The GM ones I've seen came with a red dry threadlocker actually under the washer at bolthead.  The NAPAones I've seen are naked.  Given the direction the crank spins I doubt you'd 'need' threadlocker, but the presence on the OE bolt would have me using a little loctite blue on say a NAPA bolt. Blue does not require a torch to loosen/disassemble.

I know some guys will put some RTV under the washer.  Had the director of my club tell me he does that.

That would work.

Got the right bolt.  The parts guy at the GM dealership said he couldn't get the washer, and I don't see one lying around or attached to the harmonic balancer.  If there's supposed to be one, it must be around somewhere, but there's this orange stuff on the back of the bolt head that looks like some kind of locking compound.  Why would that be there if a washer is used?  It would only lock the bolt to the washer. Are you guys sure there was a washer?

No washer as far as I know.

No washer with that style bolt.

So I put the bolt in, carefully torqued it down to 111 ft lbs, set up the torque angle gauge,  and thought to myself - "Why not turn up the setting on the torque wrench and see what it takes to turn this bolt another 76 degrees?"  Well I've turned it six degrees and I'm over 150 ft/lbs now.  Probably more like 175.  I've got the feeling something is wrong here.

Jack the R wrote:

So I put the bolt in, carefully torqued it down to 111 ft lbs, set up the torque angle gauge,  and thought to myself - "Why not turn up the setting on the torque wrench and see what it takes to turn this bolt another 76 degrees?"  Well I've turned it six degrees and I'm over 150 ft/lbs now.  Probably more like 175.  I've got the feeling something is wrong here.

The bolt will stretch.

At what point should the alarm bells be going off then?  200 ft/lbs?  250?  More?

edit - O.K. I'm up to 27 degrees now, which took 250 ft/lbs of torque!  This is bullshit!  How the hell do you specify 111 ft/lbs, like that 1 extra ft/lb makes a difference, and then specify an angle torque that is more than twice the original torque value?  If I've got to go 49 more degrees, I think I'd end up with 4-500 ft/lb!  Can that possibly be right?  You know what would have made a lot of fucking sense - just specifying the torque in ft/lbs!  Then I'd know I wasn't overtightening!  Wow, what a hard concept.  Maybe they should try teaching common sense at engineering school.  

To keep my harmonic balancer from rotating, I bolted a lawnmower blade on to the balancer with the bolts from the puller.  250 ft/lbs was enough to bend them.  Is the gauge reading correctly now?  Well, probably not.  I wish I had an idea of what the final amount of torque on this bolt is supposed to be.  Am I even in the ballpark?  Is the bolt not stretched enough, or overstretched?  It's hard to imagine it breaking, or working loose, but it's got all the vibrations of the motor working through it.  Maybe it can break.  That would be fun.  

I'm tempted to leave it as it is, unless someone knows better.  I doubt I can get an accurate measurement with the angle torque gauge now, and it probably won't work loose.

http://prod.lv2014.gener8cms.net/index.php/20-disc-brakes/section-1/tooleq/3062-torque-to-yield-and-torque-angle

https://www.onallcylinders.com/2016/08/19/ask-away-jeff-smith-truth-behind-torque-yield-fasteners-torque-angle-fastening/

Jack the R wrote:

At what point should the alarm bells be going off then?  200 ft/lbs?  250?  More?

edit - O.K. I'm up to 27 degrees now, which took 250 ft/lbs of torque!  This is bullshit!  How the hell do you specify 111 ft/lbs, like that 1 extra ft/lb makes a difference, and then specify an angle torque that is more than twice the original torque value?  If I've got to go 49 more degrees, I think I'd end up with 4-500 ft/lb!  Can that possibly be right?  You know what would have made a lot of fucking sense - just specifying the torque in ft/lbs!  Then I'd know I wasn't overtightening!  Wow, what a hard concept.  Maybe they should try teaching common sense at engineering school.  

To keep my harmonic balancer from rotating, I bolted a lawnmower blade on to the balancer with the bolts from the puller.  250 ft/lbs was enough to bend them.  Is the gauge reading correctly now?  Well, probably not.  I wish I had an idea of what the final amount of torque on this bolt is supposed to be.  Am I even in the ballpark?  Is the bolt not stretched enough, or overstretched?  It's hard to imagine it breaking, or working loose, but it's got all the vibrations of the motor working through it.  Maybe it can break.  That would be fun.  

I'm tempted to leave it as it is, unless someone knows better.  I doubt I can get an accurate measurement with the angle torque gauge now, and it probably won't work loose.

Well.. 111 ft-lb is 150 n-m. Pro torque wrenches go a lot higher - I've seen 500 lb Proto wrenches at a large local shop. I am told Proto, Wright, and others make 1" drive torque wrenches up to 1,200 ft-lbs. Think of it like winter weather. I have an outdoorsy friend who says "there's no bad weather, for the most part -- only bad/inadequate clothing." By analogy, for this job there are inadequate wrenches.

Your best bet would be to talk with a mechanic or a vo-tech teacher with engine rebuilding experience, would not be me. I think they will tell you that certain fasteners are **really** tight.

Look, it's a critical fastener that could lead to catastrophic damage to persons or equipment if done improperly. Let's figure out how to hit the spec.

LARRY70GS wrote:

http://prod.lv2014.gener8cms.net/index.php/20-disc-brakes/section-1/tooleq/3062-torque-to-yield-and-torque-angle

https://www.onallcylinders.com/2016/08/19/ask-away-jeff-smith-truth-behind-torque-yield-fasteners-torque-angle-fastening/

Well that answers a question - the final torque probably is around 4-500 ft/lbs, which completely changes the way I would have approached this repair.  I may need to hang my full body weight off the end of a 6 ft breaker bar to make that kind of force (which means the car needs to be on a lift), and I need a stouter way of keeping the engine from turning over.  I may have to invest in that $180 J 37096 flywheel holding tool.

I don't think there's a way to get a breaker bar on it from the top, but I'll go look again.

I doubt I'm going to get a precision of 76 degrees though. I hope it isn't necessary to be that precise, but the fact that it says 76 instead of 75 doesn't bode well.

LARRY70GS wrote:

https://www.dewalt.com/products/power-tools/impact-drivers-and-wrenches/20v-max-xr-high-torque-12-in-cordless-impact-wrench-with-detent-pin-anvil-kit/dcf899p1

I guess the way to tighten that bolt up is with an impact wrench and the angle torque gauge?

I would have done it that way from the start if I hadn't been so worried about overshooting the torque, i.e., if I'd known the final torque value would be over 300 and not, for example, 113.5.

You could tighten it to 111 Ft lbs.  Then mark the position of the bolt on the bolt and damper.  Then figure out where 76* is and mark it, then hit it with the impact until you get there.


That Dewalt gun has 3 levels. There is a switch on top. 1 is good for lug nuts, 2 is for really rusty or red lock tited bolts, and 3 is hold on tight or I'll break your wrist. Turn that sucker up to 3.

I'd have to loosen the bolt and start over again tightening it. Is the bolt still useable at this point? I got it up to 27-30 degrees, did it stretch too much to be reused? I would guess not, but that's just a guess.

Jack the R wrote:

I'd have to loosen the bolt and start over again tightening it.  Is the bolt still useable at this point?  I got it up to 27-30 degrees, did it stretch too much to be reused?  I would guess not, but that's just a guess.

No, don't loosen it, mark it where it is. Go another 45* or so. It does not have to be exactly 76*

LARRY70GS wrote:

Jack the R wrote:

I'd have to loosen the bolt and start over again tightening it.  Is the bolt still useable at this point?  I got it up to 27-30 degrees, did it stretch too much to be reused?  I would guess not, but that's just a guess.

No, don't loosen it, mark it where it is.  Go another 45* or so.  It does not have to be exactly 76*

Participating on this thread, I learned why you DON'T use loctite on this crank bolt. You can but on balance it makes no sense to do so. Thanks guys.

The flywheel inspection cover is the plastic job behind the oil pan and starter motor, right?  I see three fairly hefty bolts.

Looks like that's it -

LARRY70GS wrote:

 I bought this Dewalt impact gun last year.  It is incredible.

https://www.dewalt.com/products/power-tools/impact-drivers-and-wrenches/20v-max-xr-high-torque-12-in-cordless-impact-wrench-with-detent-pin-anvil-kit/dcf899p1

Got my new dcf899p1 today, charged the battery, set it to "3" - it couldn't turn the bolt any more. It couldn't even loosen the bolt, and the bolt is only torqued down to 250 ft/lbs.

I've now spent over $400 on special tools that couldn't do better than a 250 ft/lb torque wrench and an old lawnmower blade.

I don't know what to tell you Jack. It zipped my 455 crank bolt right off. Removed my flexplate bolts with Red Loctite. My GS club members swear by it. One of the best tools I have ever owned.

Is the bolt head metric? I've been using an imperial socket. Could that make a difference?

Also using an extension (it's an impact extension, and the socket is an impact socket.)

I've been trying to troubleshoot this. The wrench doesn't look like a counterfeit. I got it to break loose a smaller bolt on the Charger. 1200 ft/lbs of breakaway torque should be enough to undo 250 ft/lbs, unless the torque doesn't directly translate.

This doesn't make any sense.

Have you held the wrench on it for 20-30 seconds and just let it hammer on it?  I hope you don't think it just breaks it loose with one or 2 trigger pulls.  Impact wrenches hammer at the bolt.  That's how they work.

More like 10-15. A 15/16's socket has a bit of play in it, may not be transferring the energy right? I'm going to get a mm set and try again.

Jack the R wrote:

More like 10-15.   A 15/16's socket has a bit of play in it, may not be transferring the energy right?  I'm going to get a mm set and try again.

Yes, you must have the right socket. My flex plate to crankshaft bolts with red loctite took a good 30 seconds or more to get loose. Hold the trigger down and let it eat. I mark the black impact socket with a silver sharpie so that I can see it turn amidst the vibrations.

Unless the HB bolt is 23 mm, I should be fine though. 15/16s works out to 23.8125 mm, so it's a little tighter than 24 mm. Most impact socket sets I see have 22mm and 24 mm, skipping 23mm. 23mm is available individually. Does anyone know if this is a 23 or 24 mm socket?

Answer - it's a 24mm socket.

With the 24mm socket the dcf899p1 cranked the bolt around like I expected it too.  I had to recharge the battery about halfway through, but it got the job done.  

The 24mm socket felt the same on the bolt as the 15/16's.  I can hardly believe there's any difference, but one worked and one didn't.  

On to the next job . . .



edit - BTW, my Riv also started without a case learn.