crank pully question
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 798
Likes: 2
From: Notorious Miami sunny south florida
crank pully question
can someone tell me what is the torque on the crank pully bolt
mine seems to keep coming loose . I here its some outragous number is this true
mine seems to keep coming loose . I here its some outragous number is this true
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 798
Likes: 2
From: Notorious Miami sunny south florida
Thanks 02GT350 I check it daily but its getting old I'm going to buy a new bolt lock tight it and then torque it it a lot of work just to take the bolt out much less tighten it with the rack in the way replaceing the pully was a project like every thing else on the C5 but if you want to drive the best sometimes youll have to work on it . It comes with the territory
Pro
Joined: Aug 2000
Posts: 517
Likes: 0
From: Arlington Texas
If you're using the stock bolt then there is no final torque number. It's a stretch bolt that is tightened by turning the bolt 240 degrees after snugging it up to 37 lb/ft. You also cannot reuse the bolt. It sounds like you replaced the balancer. Did you replace the bolt at that time? If so, did you stretch it properly?
Drifting
Joined: Oct 2004
Posts: 1,384
Likes: 8
From: Southwest Virginia
I is very likely your balancer is moving on the crank if your bolt keeps coming loose. For some strange reason GM did not put a keyway in the balancer on the LSx engines. They put keyway in the crank for the timing chain, so it would probably costed less than $0.35 per engine to have done it right and no one would ever have had these problems. But you can pin your balancer and crank, put in a new properly torqued bolt, and never have another problem with it ever. I think A&A sells a crank pinning kit for $30-$40 range.
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
You have a few options... if you never want to think about it again pin the crank.
There are 2 types of pin setups. One goes in the face of the crank/pully on the horizontal axis. This works well, but if you ever have to take it off, getting it all re-alligned to get back on could be tricky.
When doing my cam install I chose an ATI super damper becuase it's one of the best actual dampeners out there. It comes w/ a key way. With this kit you drill into the crank snout on the vertical axis, install a pin, then slide the pulley on.
Normal crank snout
Pin hole drilled... sorry don't have a shot of the fixture to drill it, but you buy it from ATI, I borrowed one from England Green.
New balanceer compared to stocker
Balancer installed
Now the balancer cannot move on the crank... the issues is that the belt/accessories put force on the pulley that makes it want to rotate and spin the bolt out. This can't happen now.
Technically the super human torque value isn't needed anymore, but I did it anyway. www.ls1howto.com has the exact instructions.
HTH,
Brian
There are 2 types of pin setups. One goes in the face of the crank/pully on the horizontal axis. This works well, but if you ever have to take it off, getting it all re-alligned to get back on could be tricky.
When doing my cam install I chose an ATI super damper becuase it's one of the best actual dampeners out there. It comes w/ a key way. With this kit you drill into the crank snout on the vertical axis, install a pin, then slide the pulley on.
Normal crank snout
Pin hole drilled... sorry don't have a shot of the fixture to drill it, but you buy it from ATI, I borrowed one from England Green.
New balanceer compared to stocker
Balancer installed
Now the balancer cannot move on the crank... the issues is that the belt/accessories put force on the pulley that makes it want to rotate and spin the bolt out. This can't happen now.
Technically the super human torque value isn't needed anymore, but I did it anyway. www.ls1howto.com has the exact instructions.
Seat your pulley back onto the snout of the crankshaft as best you can by hand. If you purchased a longer crank bolt, start threading this in now and pull the pulley on about a 1/4 or 1/2 an inch and remove the longer bolt. Use your old stock crank pulley bolt to pull the pulley onto the crankshaft until the bolt seems to get impossible to turn. Grab your biggest torque wrench and attempt to torque that bolt down to 240lbft. I have always stopped at 200lbft on my installs and I've never had a problem, so if you can't hit 240 (which I never have), don't worry about it. Now, break the bolt free and remove it.
Take your NEW crank pulley bolt and thread it in all the way by hand. Torque this bolt to 37lbft. Now, we need to stretch the bolt into place. Get your breaker bar and pipe extension, and try to turn the bolt 140degrees past where it is at now, keeping in mind the engine will be trying to turn some and those are degrees you can't count. Again, I always seem to get about 90-100 degrees worth (estimating, knowing what 90 degrees looks like) and leave it as is so don't worry about going crazy here.
Take your NEW crank pulley bolt and thread it in all the way by hand. Torque this bolt to 37lbft. Now, we need to stretch the bolt into place. Get your breaker bar and pipe extension, and try to turn the bolt 140degrees past where it is at now, keeping in mind the engine will be trying to turn some and those are degrees you can't count. Again, I always seem to get about 90-100 degrees worth (estimating, knowing what 90 degrees looks like) and leave it as is so don't worry about going crazy here.
Brian
