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Krambo

Crank Shaft Pulley Pinning

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Not too many trucks will require a crank pulley pin but for the few that are spinning higher RPM's and have a supercharger adding rotational load to the pulley, here is a quick step by step to help cure those high RPM woes.

 

First, remove the original crank shaft bolt using a 24mm deep socket, breaker bar and a jam tool of your choice (large screw driver, lug nut wrench etc.). Wedge the large screw driver through the pulley so that the back end of the screw driver is resting on a SOLID surface to prevent the pulley from spinning as you back out the bolt. Most likely, this will take some muscle but it will come out :D

 

Once the bolt is out, you can begin the pinning process. I removed the plastic shield under the truck to gain better access. The following picture is what I used to get the job done. It consists of a new GM crank shaft pulley bolt, a longer bolt, a jig, two hardened steel pins, drill bit of the same diameter as the pins and a reamer.

 

102_0823.JPG

 

 

This is obviously a kit but it is not necessary to find a kit for your needs. You can use the shanks off a hardened steel drill bit for the pins and just have a steady hand when drilling instead of using a jig.

 

Next step will be to use the longer bolt and secure the jig onto the crank pulley. Tighten the jig down to 30 ft/lbs to prevent movement. FYI, 30ft/lbs was just enough to spin the crank on the motor without a bar preventing the pulley from spinning.

 

102_0874.JPG

 

 

You are now ready to drill out the two holes for the pins. I used a small amount of WD40 when drilling and used a small 12V cordless drill. The area is tight. If you do not have E-fans, you may have to remove the fan shrouds. Once the holes are drilled to the pre-set depth of the jig, use the reamer to hone the holes and "flatten" out the end of the holes so that the pins will seat when you tap them in. Use compressed air to blow out the newly drilled holes. I used break cleaner with the long red tube to get way into the holes and push all of the crap out. Now remove the jig and take a look at the result. Notice the placement of the holes,...splitting the difference between the pulley edge and the crank end material.

 

102_0877.JPG

 

 

Once you have cleaned up the all the shavings, you can now tap in the 2 pins. Be sure they are seated all the way in and they will not interfere with the new crank shaft bolt when re-installing.

 

102_0883.JPG

 

 

Now the fun part, reinstalling the new crank bolt :sigh: Again, make sure that you do not have any shavings in the bolt path and then twist in the new bolt. I added additional Loctite at this point for additional security. Tighten the bolt to 37lb/ft (50N-m) After tightening to 50N-m, use chalk to scribe a line across the bolt head strait through the pulley face. This will be your ZERO* mark for the fun part. If you like to buy new tools for the job, here is your chance. You can buy a "torque angle meter" and not need chalk. My pics are out of focus but I assure you that there is a line across the bolt head and pulley face.

 

102_0886.JPG

 

 

O.K. crack you knuckles and get ready to break a sweat. You now need to tighten down the bolt another 140* past the ZERO* mark you scribed. As soon as you start to do this you will realize how much force you are going to need. For reference, I got it to 90* and hit exactly 200lb/ft. :sigh: Lay underneath the truck and place your feet on the driver's side tire and give her hell. Now, it isn't exact science here (using a protractor) but I hit 140*. The Loctite is just a warm fuzzy. See picture:

 

102_0890.JPG

 

 

Now you are ready to spin that motor to 7K! with no worries! :thumbs:

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I had one battle scar...bent the crap out of my 4" extension. :shakehead:

 

 

102_0891.JPG

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nice :thumbs: - cant wait for this.... :sigh:

Edited by FuelSlut

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Now you are ready to spin that motor to 7K! with no worries!  :thumbs:

I wouldn't exactly think there are "no" worries for going to 7k, but I will go with no crank spin :thumbs:

 

Good job on the how-to. So what kind of provisions is made for removing it? Can the pins be removed and re-used?

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Now you are ready to spin that motor to 7K! with no worries!  :thumbs:

I wouldn't exactly think there are "no" worries for going to 7k, but I will go with no crank spin :thumbs:

 

Good job on the how-to. So what kind of provisions is made for removing it? Can the pins be removed and re-used?

 

 

I hear ya on the 7K ;) I personally spin her to 6250. Anyway, the pins are not glued in place and will easily fall out when you take the pulley off....if you need to. The real trick will be aligning each half of hole when re-installing the pulley if you for some reason had to take it off :sick:

 

Another thought is that a single pin would be fine IMO as long as it was made out of the right material (hardened steel).

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I have a 4 foot tw at work that runs to 600 ft/lb. I think that will do!! :crazy:

 

My question is, is crank spin really a problem?

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Another thought is that a single pin would be fine IMO as long as it was made out of the right material (hardened steel).
I'm going to very respectfully disagree here, for a subtle reason: you want to keep the crank in balance. One hardened pin will certainly be strong enough to hold the damper from slipping but I would advise using two pins exactly 180-degrees from each other (use a commercial jig/kit) so that weight is added evenly to the crank to minimize balance issues.

 

Mr. P.

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Another thought is that a single pin would be fine IMO as long as it was made out of the right material (hardened steel).
I'm going to very respectfully disagree here, for a subtle reason: you want to keep the crank in balance. One hardened pin will certainly be strong enough to hold the damper from slipping but I would advise using two pins exactly 180-degrees from each other (use a commercial jig/kit) so that weight is added evenly to the crank to minimize balance issues.

 

Mr. P.

 

 

I hear ya...but I have a single 3/16 (if I remember correctly) pin in mine. I figured that since I was removing material of similar density that replacing it with a very near equal amount of material would be fine. That combined with the fact that it is very close to the center of the crankshaft and at the very end of it would lead me to think (don't know if I'm right) that it will change the engine balance very little. This is what I told my self when I did it, I didn't want to press my luck doing a second pin when I did such a nice jod of free handing the first one. Also on the old sbcs and bbcs they had a single woodruff key to clock the balancer in it's proper position. JMHO....later

 

Dave

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I hear ya...but I have a single 3/16 (if I remember correctly) pin in mine. I figured that since I was removing material of similar density that replacing it with a very near equal amount of material would be fine. That combined with the fact that it is very close to the center of the crankshaft and at the very end of it would lead me to think (don't know if I'm right) that it will change the engine balance very little. ...
Yeah Dave you're right, I'm wrong. I forgot about that fact. Apologies to everyone for putting my foot in my mouth. :banghead:

 

Mr. P.

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I hear ya...but I have a single 3/16 (if I remember correctly) pin in mine. I figured that since I was removing material of similar density that replacing it with a very near equal amount of material would be fine. That combined with the fact that it is very close to the center of the crankshaft and at the very end of it would lead me to think (don't know if I'm right) that it will change the engine balance very little. ...
Yeah Dave you're right, I'm wrong. I forgot about that fact. Apologies to everyone for putting my foot in my mouth. :banghead:

 

Mr. P.

 

 

I wasn't tryin to down you or anything...we all have different ways of looking/thinking about stuff. You didn't put your foot in your mouth, you were just trying to make sure every angle was covered and that no one was gonna mess anything up.

 

Dave

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just a bump for something that is needed for a supercharged application imo, i did my crank pin last week and almost shat myself, when i went to go to pull the stock crank bolt out, i didnt need a wrench, it was less than finger tight, it was loose as a......well nevermind but it kind of scared me. i am very happy i did this my crank had been spinning alot . i didnt think it would be that big of a problem i was just doing for more of a precaution. also a very nice kit too , now i can pin more crank pullies if need be, all i need is some hardened steel rod.

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Not too many trucks will require a crank pulley pin but for the few that are spinning higher RPM's and have a supercharger adding rotational load to the pulley, here is a quick step by step to help cure those high RPM woes.

 

First, remove the original crank shaft bolt using a 24mm deep socket, breaker bar and a jam tool of your choice (large screw driver, lug nut wrench etc.). Wedge the large screw driver through the pulley so that the back end of the screw driver is resting on a SOLID surface to prevent the pulley from spinning as you back out the bolt. Most likely, this will take some muscle but it will come out :D

 

Once the bolt is out, you can begin the pinning process. I removed the plastic shield under the truck to gain better access. The following picture is what I used to get the job done. It consists of a new GM crank shaft pulley bolt, a longer bolt, a jig, two hardened steel pins, drill bit of the same diameter as the pins and a reamer.

 

post-1292-1144004169_thumb.jpg

 

 

This is obviously a kit but it is not necessary to find a kit for your needs. You can use the shanks off a hardened steel drill bit for the pins and just have a steady hand when drilling instead of using a jig.

 

Next step will be to use the longer bolt and secure the jig onto the crank pulley. Tighten the jig down to 30 ft/lbs to prevent movement. FYI, 30ft/lbs was just enough to spin the crank on the motor without a bar preventing the pulley from spinning.

 

post-1292-1144004841_thumb.jpg

 

 

You are now ready to drill out the two holes for the pins. I used a small amount of WD40 when drilling and used a small 12V cordless drill. The area is tight. If you do not have E-fans, you may have to remove the fan shrouds. Once the holes are drilled to the pre-set depth of the jig, use the reamer to hone the holes and "flatten" out the end of the holes so that the pins will seat when you tap them in. Use compressed air to blow out the newly drilled holes. I used break cleaner with the long red tube to get way into the holes and push all of the crap out. Now remove the jig and take a look at the result. Notice the placement of the holes,...splitting the difference between the pulley edge and the crank end material.

 

post-1292-1144005459_thumb.jpg

 

 

Once you have cleaned up the all the shavings, you can now tap in the 2 pins. Be sure they are seated all the way in and they will not interfere with the new crank shaft bolt when re-installing.

 

post-1292-1144005875_thumb.jpg

 

 

Now the fun part, reinstalling the new crank bolt :sigh: Again, make sure that you do not have any shavings in the bolt path and then twist in the new bolt. I added additional Loctite at this point for additional security. Tighten the bolt to 37lb/ft (50N-m) After tightening to 50N-m, use chalk to scribe a line across the bolt head strait through the pulley face. This will be your ZERO* mark for the fun part. If you like to buy new tools for the job, here is your chance. You can buy a "torque angle meter" and not need chalk. My pics are out of focus but I assure you that there is a line across the bolt head and pulley face.

 

post-1292-1144006382_thumb.jpg

 

 

O.K. crack you knuckles and get ready to break a sweat. You now need to tighten down the bolt another 140* past the ZERO* mark you scribed. As soon as you start to do this you will realize how much force you are going to need. For reference, I got it to 90* and hit exactly 200lb/ft. :sigh: Lay underneath the truck and place your feet on the driver's side tire and give her hell. Now, it isn't exact science here (using a protractor) but I hit 140*. The Loctite is just a warm fuzzy. See picture:

 

post-1292-1144007388_thumb.jpg

 

 

Now you are ready to spin that motor to 7K! with no worries! :thumbs:

I would just like to say thank you very much for this post i followed your steps i used 2 pins under half an inch in lenth 3/16 diameter and pined my crank i got the pins for a cup of coffee the guy at the machine shop said i cant charge you for a 3/16 pin and he even tappered the pin just a touch then he told me to use a drill bit one size smaller then use the 3/16 so i did one at a time and put a touch of high heat gasket maker on the tip of pin tapped it in and went on to the next one finished that put some lock tight on threads and some high temp on the bottom of bolt head tightened it to 37lb then i used a snap on twrench and tq it to 240. i did not use the chauk line because my motor is on a stand and i locked the flywheel. well i lied a bit im only 135 pounds i only got it to 230 and my buddy who is over 200lbs tq it the rest of the way because i had nowhere to put my feet to pull. i blew my first engine a 5.3 kb supercharged 9lbs and now i putting in a 6.0 and i am doing everything possible not to blow another eg. rod bolts crank pinning, oil pump double timing chain for acurate timing valve springs push rods and a good tune. thanks again im driving a tahoe ss Clone. because they never made a real one, just a concept. THESS005.jpg

THESS006.jpg

Edited by djokr1100

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Man alive you guys weren't exaggerating on the difficulting of removing / installing that bolt.

 

Was trying to do this mod tonight, but can't get the bolt out.

Is it safe to let your "jam bar' rast on the aluminum support bracket under the powersteering pump?

 

I'm working it and don't want to break anything.

 

The how to is great, but a newbie like me would like to see a pic of "jam' methods to stop the crank from turning.

 

Is there any special tool that can be purchased or borrowed to stop the crank from spinning? How would a dealer accomplish this?

Edited by Fourtraxjay

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