Crankshaft Pulley, Seal, Bolt - Replace

[donjetman]

07 6.2L w/193k miles
Bought the tools so I can change the pulleys on the 3 LS powered vehicles we own.
I've decided to not use the ARP bolt on The Denali, and I'm waiting for a stock bolt, GM # 12557840, to arrive.

 

[Geotrash]

07 6.2L w/193k miles
Bought the tools so I can change the pulleys on the 3 LS powered vehicles we own.
I've decided to not use the ARP bolt on The Denali, and I'm waiting for a stock bolt, GM # 12557840, to arrive.
View attachment 417080

Why not use the ARP bolt? I used one during the cam swap on my 2012 and it's been flawless for 30K miles. I like the reusability.

 

[donjetman]

Why not use the ARP bolt? I used one during the cam swap on my 2012 and it's been flawless for 30K miles. I like the reusability.

I'm using the ARP ($40) on my Corvette.
I'll use the much cheaper ($13) stock bolt on my Yukon and LS swapped 51 Chevy PU.

 

[j91z28d1]

I still have nightmares about the c6 one pulling the rack on my back lol. glad you have a lift.


the thing I don't get about the arp is isn't the tq spec like 180? but if you use the stock bolt, you end up at almost double the arp tq spec. seems odd but a reason I went with the oem bolt on my c6. that and I don't plan to ever do it again haha.

I did go with a 10% under drive crank and oem size ac part. no cooling issues at idle or on track and it did feel a little crisper throttle response. seems pointless to do it on a truck, but the manual c5 might be a thing.

 

[donjetman]

Yeah, when @skpyle did the stock torque to yield bolt it took almost 300 ft/lbs. Crazy

 

[Foggy]

I used the arp on my C5 and my Denali...
The torque required for a factory spec is stupid...
I felt a lot better just threading the ARP into the crank snout with
some loctite at ( i think) 110 lb ft... Whatever arp said to do..
The GM wants tons of torque then add the degrees ... I just didnt' want to
take any chances in fuc&in up the crank threads since both were still in the cars
Don't care too much about "reuseble" as $35 is really not even a drop in the bucket
if you have to pull out an engine to do major work

 

[j91z28d1]

it's also very very had to get that tight lol. I had to just make the deg marks and breaker bar and long pipe.

I did search around and never found anything about anyone stripped a crank at the factory spec and the bolt does have a locking compound in the threads and a friction coating under the head where the arp probably calls for their molly lube?


there was some talk of a friction washer between the crank and balancer but I never saw anything on my, and lots of posts by people saying they didn't have one either oem

 

[donjetman]

I have a LOOOOONG handle torque wrench good for up to 600 ft/lbs. Lug nuts on my Prevost MH get torqued to 450.

 

[Geotrash]

I’m super rigid about using a torque wrench for everything with a spec, but for the ARP crank bolt I just gave it some solid ugga duggas with my Earthquake air impact wrench and marked it with a paint pen. Hasn’t budged since.

 

[iamdub]

...the thing I don't get about the arp is isn't the tq spec like 180? but if you use the stock bolt, you end up at almost double the arp tq spec. seems odd but a reason I went with the oem bolt on my c6. that and I don't plan to ever do it again haha.

Totally different bolts. You still end up at the same amount (or within an acceptable range) of clamping force, which is ultimately the goal.

The stock bolts stretch. They calculate the stretch of the bolt by the degree of the threads and degrees of rotation, the elasticity of the bolt, etc. yielding X amount of clamping force. It takes a higher torque spec because the friction between the bolt head and pulley is high, but the required clamping force isn't yet achieved. The ARP bolt is a much harder material so, when it's turned X degrees and the threads are pulling through the crank while the head is bottomed out, that same (or thereabouts) specified clamping force is achieved much quicker. Because they're not factoring stretch, they've calculated their own torque spec with no other stipulations. That torque value is much lower than the factory bolt cuz it hits that required clamping force much quicker and at that lower torque spec after bottoming out than the stock bolt does.