Stripped crank threads, failed Helicoil
Stripped crank threads, failed Helicoil I bought a used engine and its got issues, the crank bolt had washers stacked on it and the bolt was not a GM one. A failed helicoil attempt has it messed up.
Has anyone seen the end of the crank snout threaded? This crank has threads all the way to the end. They appear to be 18mmx? Anyone know the size of the tap and thread pitch?
Down inside the hole it appears to step down into the 16mmx2 factory threads(that are now gone).
If I can find out what threads the snout is I will drill and tap them all the way in and put that size bolt in it. Or just find that bolt size, the 18mm and use it for the balancer as its twice the number of threads than the factory just not quite as deep.
Any info on this or my thinking?
Has anyone seen the end of the crank snout threaded? This crank has threads all the way to the end. They appear to be 18mmx? Anyone know the size of the tap and thread pitch?
Down inside the hole it appears to step down into the 16mmx2 factory threads(that are now gone).
If I can find out what threads the snout is I will drill and tap them all the way in and put that size bolt in it. Or just find that bolt size, the 18mm and use it for the balancer as its twice the number of threads than the factory just not quite as deep.
Any info on this or my thinking?
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Brett Foote Tap $42
http://www.holesawsunlimited.com/pro...roductid=18196
Drill bit$21
http://www.biscotoolsupply.com/home/....html?rid=base
Total less than $85
http://www.holesawsunlimited.com/pro...roductid=18196
Drill bit$21
http://www.biscotoolsupply.com/home/....html?rid=base
Total less than $85
Last edited by FASTFATBOY; Aug 29, 2011 at 09:44 PM.
No problem , but I would use a drill press and see how centered and straight the drilling action starts and if straight keep an eye on it about every 1/4 " to make sure it stays centered . It does'nt have to be 100% centered but should not be off more than 1/32" or it will create a vibration , albeit a small vibration but not good either way . I know You can drill it by hand which does work well maybe 60-80% of the time but it seems to not work well when it's most important , like crank bal bolt hole . I bought a Silver & Deming drill set from Harbor Freight for $35 and although not the highest quality bits in the world , they are surprizingly good . They are 9/16", 5/8", 11/16", 3/4", 13/16", 7/8", 15/16" and 1" . I know You're not gonna use amer threads but I've got a 3/4"10 nat course tap that You would use a 5/8" drill to drill the hole . The 3/4" tap is almost identical in size to a 19mm bolt so You may not even need to drill if the existing threads are16mm and thenew size is 18 or 19mm . You might want to use 19mm to make sure You're cutting all of the thread n not missing some of thread if the drilled hole is a little bit too large . good luck
Last edited by chrisfrost; Aug 29, 2011 at 09:45 PM.
I snapped the main bolt once in the crank of my 5.3 from cross-threading it, so I took it to a machine shop, and they ended up threading the first few inches of the snout for an aftermarket bolt. I ran it like that for several thousand miles without a single issue. Cost about $60. They also ended up fixing the OEM threads, but they actually told me the setup that they did was stronger than OEM, and none of that TTY BS.
I have decided to pin the balancer to the crank, screw in another heli-coil not as deep as the other one, use a standard bolt and torque to around 80 ft lbs.
Andrew, what did you torque yours to?
BTW guys, I bought this engine off this board. Shortly after buying it the seller deleted the post.....he knew it had issues.
Andrew, what did you torque yours to?
BTW guys, I bought this engine off this board. Shortly after buying it the seller deleted the post.....he knew it had issues.
I have decided to pin the balancer to the crank, screw in another heli-coil not as deep as the other one, use a standard bolt and torque to around 80 ft lbs.
Andrew, what did you torque yours to?
BTW guys, I bought this engine off this board. Shortly after buying it the seller deleted the post.....he knew it had issues.
Andrew, what did you torque yours to?
BTW guys, I bought this engine off this board. Shortly after buying it the seller deleted the post.....he knew it had issues.
I have drilled them out and re tapped to 7/8"-14 on three engines. All with excellent results, a plus side is that the bolt is no longer over stressed, even an arp bolt is almost torqued to it's yield. While thats the point to keep it tight, when you have the balancers on and off alot, it still f's the threads, just a matter of time. So, 7/8-14 with a little dab of loctite, and it's done.
Here's a pic sorta, you can see bolt on the crank
Here's a pic sorta, you can see bolt on the crank
Well I buuggerd up my crank and 2 ARP bolts following th GM balancer pulley install instructions.
Attachment 251488
Ended up rethreading with out drilling to 3/8-16 and useing the all thread method of pulling the HB pulley on.
The funny thing is the ARP bolts seemed to have different threads piches and counts from one another eventhough they were both supposed to be for LS1-6 engines??
I just used a grade 8 allen torqued to 175 with red loctite. and opened up the ARP washer to 3/8 on my shops lathe.
7500mi no issues so far.
Attachment 251488
Ended up rethreading with out drilling to 3/8-16 and useing the all thread method of pulling the HB pulley on.
The funny thing is the ARP bolts seemed to have different threads piches and counts from one another eventhough they were both supposed to be for LS1-6 engines??
I just used a grade 8 allen torqued to 175 with red loctite. and opened up the ARP washer to 3/8 on my shops lathe.
7500mi no issues so far.
Last edited by Anthony Williams; Aug 31, 2011 at 03:24 PM.
The crank is trashed I think, I have tried to contact the seller numerous times to get some help. He has not responded.....he was on this board this morning.
I requested $350 to put a crank in it. We will see if he replies, he hasn't up till now.
I have sent pm, text and e mails with no response. You would think with his prefect trader rating on here he would step up.
I requested $350 to put a crank in it. We will see if he replies, he hasn't up till now.
I have sent pm, text and e mails with no response. You would think with his prefect trader rating on here he would step up.
http://s430.photobucket.com/albums/q...t=M4V03456.mp4
The crank is trashed I think, I have tried to contact the seller numerous times to get some help. He has not responded.....he was on this board this morning.
I requested $350 to put a crank in it. We will see if he replies, he hasn't up till now.
I have sent pm, text and e mails with no response. You would think with his prefect trader rating on here he would step up.
I requested $350 to put a crank in it. We will see if he replies, he hasn't up till now.
I have sent pm, text and e mails with no response. You would think with his prefect trader rating on here he would step up.
Seems like you guys make a living buying motor's and then trying to sue for your money and getting a free motor. just so happens I know the last guy you tried this on and why didn't you mention you had it for 2 months before you decided to come with this bogus claim, even if it is stripped how do I know you didn't do it while trying to remove the balancer and if it was already stripped how was the balancer even back on the crank?? and you act like I've been dodging you, the first email about this BS was 2 days ago.
https://ls1tech.com/forums/negative-...ll-mmckee.html
Last edited by Ego Killer; Aug 31, 2011 at 08:33 PM.