RebelExtrm02

iTrader: (3)

Previous owner modded the motor and installed the arp crank bolt. I'm opening up the motor to freshen up the seals. When I removed arp crank bolt there was a lot of drag the whole way out of the hole, as in I had to use enough force on my ratchet post breaking the bolt loose to wear me out by the time the bolt came completely out of the hole. When I got the arp bolt out I looked at it and the first three threads on it are jacked and have material impacted between them from the crank. I know this hurt the threads in the crank, I'm just trying to gauge how badly based on how much force I used turning it out. I can't see far enough into the crank hole to get a visual on them. Would it be worth using a chaser on the threads on this crank and getting a new bolt or is the crank likely trashed?

Anyone want to guess how the arp bolt got chipped like that? My thought is that the previous owner used the arp bolt to pull the pulley on but I would have figured that would have damaged the crank threads before the hardened bolt threads.

cmac06

iTrader: (16)

Looks trashed, you try chasing the threads in the crank to see if they are damaged?

RebelExtrm02

iTrader: (3)

I haven't gotten that far yet. I just pulled that bolt out about an hour ago. I know they are damaged to some degree because of the material transfer on the bolt. I was hoping to get some input on whether or not anyone would try to chase the threads in a crank if they pulled that bolt through it. I don't know how much pressure is on the threads once everything is installed so I didn't know if it was worth it to try and chase the threads or if things like this usually mean the crank is junked. The arp bolt is going to be tossed for sure. Even if I fixed the threads on it I don't trust it any more.

RockinWs6

Bolt was too long...............typical ARP bs. Good luck

kinglt-1

iTrader: (26)

Its not typical bs...arp makes 2 different length bolts.

vettenuts

iTrader: (4)

You assessment would be my first thought as well. Do you have a stock bolt you can run up the threads to see if it goes in OK? I would be concerned with running a tap at this point until you figure out the situation.

At least you have the bolt out so some type of repair can be done if necessary. Too many guys bugger it up then break to bolt on top of it all.

RebelExtrm02

iTrader: (3)

I'm going to purchase a stock bolt at the dealer to check with and then notch it with a dremel to chase the threads down. Does this sound reasonable?

Also, I measured the ARP bolt I removed and it came out to a hair over 4-5/16" which puts it in spec with ARP's listed 4.325" length for the Chevrolet Gen III/LS Series small block bolt.

RockinWs6

I'd get the proper tap and do it.

KCS

iTrader: (20)

Don't use a tap. A tap is meant to cut threads and can weaken the existing threads. Using a chase is a much better idea. Cut the notches in a stock bolt like you said and deburr it with a wire wheel; that will work great.

RockinWs6

I disagree strongly, those threads are damaged they need to be recut properly. Chasing it with a bolt is not going to cut the damage away.

KCS

iTrader: (20)

It depends on the damage. If the damage is such that a thread chase won't work, I prefer to drill it out and use a tap to cut new threads. That's what a tap is meant for and how threads are properly recut.

kinglt-1

iTrader: (26)

KCS knows his stuff I would listen to his advice.

Redbull87

iTrader: (3)

Oddly enough I was just doing this yesterday.i had to change my crank pulley to an asp unit. Ive had my stock pulley on/off multiple times the past few weeks and used the original bolt to pull the pulley on then remove it and use the arp to finish torque it down.

Ive made the mistake of reusuing the original bolt which at the time didnt know it was tty bolt and when removing it I had a damaged bolt thread and some particles of the red locktite I used.I went to thread my new arp bolt in and had resistence within 3 turns by hand.Uh oh! So i did exactly what KCS suggested.Bought another stock bolt..its cheap.My original bolt i cut and made a chaser with it.Threaded it in/out a few times and all went well.I then blew out the bolt hole with air.I was then able to thread the arp bolt completely by hand with ease and no sign of damaged crank threads.I then proceeded with the arp suggested install guide with their assembly lube and torqued it down.

I doubt the crank itself has any damage..more like the bolt itself leaving metal particles you need to clean out thoroughly.Btw my arp bolt had a washer and depending on which length stock bolt came out you would need it or not.I needed the washer on my application seeing as I have an lq4 bolt your supposed to use their assembly lube on the entire bolt and the mating surface of the bolt head as per instructions.

Good luck.