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Discussion Starter #1
Messing with a friends LS2 out of his Trailblazer SS. Got the timing cover off and noticed that there is one large bolt holding the cam sprocket on instead of three bolts like I've seen in other LSx applications.

Well I put a socket on it and reefed on it pretty good, but it just won't break loose. I tried both directions in the event that it was a reverse thread for some queer reason. So I have two questions.

1) When did the LSx switch over to this type of cam sprocket bolt?
2) Has anyone had issues removing said bolt, I'm inclined to try the impact on it.
3) I assume its torque to yield, does anyone know the part number or torque value of the bolt??

Thanks very much for any help.
 

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If you have not done one of these yet,you may want to pay someone.

BTW-Are you putting a different cam in?

If so you may want to order a few parts from me,we stock all the parts to do the job correctly.

Andy
 

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2007 chevy trailblazer_ss_3ss
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Messing with a friends LS2 out of his Trailblazer SS. Got the timing cover off and noticed that there is one large bolt holding the cam sprocket on instead of three bolts like I've seen in other LSx applications.

Well I put a socket on it and reefed on it pretty good, but it just won't break loose. I tried both directions in the event that it was a reverse thread for some queer reason. So I have two questions.

1) When did the LSx switch over to this type of cam sprocket bolt?
2) Has anyone had issues removing said bolt, I'm inclined to try the impact on it.
3) I assume its torque to yield, does anyone know the part number or torque value of the bolt??

Thanks very much for any help.
07's came that way. If you leave the chain on he cam and crank you ought to be able to break it free that way. I do not believe its a torque to yield bolt. you can replace it with a 05-06 LS2 3 bolt gear.
 

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Messing with a friends LS2 out of his Trailblazer SS. Got the timing cover off and noticed that there is one large bolt holding the cam sprocket on instead of three bolts like I've seen in other LSx applications.

Well I put a socket on it and reefed on it pretty good, but it just won't break loose. I tried both directions in the event that it was a reverse thread for some queer reason. So I have two questions.

1) When did the LSx switch over to this type of cam sprocket bolt?
2) Has anyone had issues removing said bolt, I'm inclined to try the impact on it.
3) I assume its torque to yield, does anyone know the part number or torque value of the bolt??

Thanks very much for any help.
I received your PM, but figured I would post the response here for others as well.

In '07 GM switched to the single-bolt cam sprocket. Assuming that you are doing a cam-swap and your cam has the earlier 3-bolt sprocket setup, you can purchase a conversion kit from Lingenfelter. (You could piecemeal it elsewhere, but IMHO this is most convenient - all as a 'kit' and easy online ordering)

http://www.lingenfelter.com/store/ls2camkit.html

It includes all that you need for the swap.

The single-bolt isn't reverse thread, and like Alvin said if you have the chain installed (still should be at this step) you should be able to break it free. Its possible that it was cross-threaded from the factory, hence the reason why its sooo tight - because its not a TTY bolt, and IIRC the torque specification for that bolt is fairly low.

Good luck!
 

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Discussion Starter #5
Thanks for all of the input here fellas. I'm more than capable here, I've built over 20 LSx engines and done head and cam work on countless vehicles since the LS1's release in 98. This is the first time I have seen this though, and I wanted to do a little homework before I went tearing through things. I do like the timing chain guide though. Most LSx engines I've seen have borderline slack in the timing chain. This takes up a lot of that.

I know the three bolts in the pre 07 cam sprocket are 24ft/lb each and they are small bolts. So I assume it doesn't have a high torque value. I agree on the slight cross thread or being seized. I'm going to crack into it later today or tomorrow.

Thanks Again.
 

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A couple pointers since you seem to be listening:

Chain part numbers are the same.
Lower sprocket is the same.
Cam sprocket-Use only 2006 C-6 Corvette.(On this job)
DO NOT UNDER ANY CIRCUMSTANCES USE A 2005 LS2 OF ANY VEHICLE MAKE.
Do not use the existing chain dampner from the 2007.
Only use the dampner from the LPE kit(Or 2006 corvette dampner)
Take a very close look at the cam gear(2007 single bolt) you remove...every third tooth is a different pitch.Also if you digitize the 2 gears(2006 versus 2007) you will find that one is actually smaller in diameter.

Do your self a favor and buy the kit from LPE or my self.

There are many people here that have put cams in these 2007 awd trucks that did not go to the extra effort to change the dampner,these guys are on borrowed time.The 2007 cam gear with the odd teeth creates a harmonic that requires the new style dampner(tensioner),when installing the wrong combination of gears /dampners/tensioners you will see catastrophic failure.


Buld it the way GM designed it in the first place,don't move off the path.If you use 2006 corvette gear,than use all 2006 parts.

BTW-It is 26 ft lbs on cam gear and 18 ft lbs on front cover etc.


My .02

Andy
 

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Discussion Starter #7
A couple pointers since you seem to be listening:

Chain part numbers are the same.
Lower sprocket is the same.
Cam sprocket-Use only 2006 C-6 Corvette.(On this job)
DO NOT UNDER ANY CIRCUMSTANCES USE A 2005 LS2 OF ANY VEHICLE MAKE.
Do not use the existing chain dampner from the 2007.
Only use the dampner from the LPE kit(Or 2006 corvette dampner)
Take a very close look at the cam gear(2007 single bolt) you remove...every third tooth is a different pitch.Also if you digitize the 2 gears(2006 versus 2007) you will find that one is actually smaller in diameter.

Do your self a favor and buy the kit from LPE or my self.

There are many people here that have put cams in these 2007 awd trucks that did not go to the extra effort to change the dampner,these guys are on borrowed time.The 2007 cam gear with the odd teeth creates a harmonic that requires the new style dampner(tensioner),when installing the wrong combination of gears /dampners/tensioners you will see catastrophic failure.


Buld it the way GM designed it in the first place,don't move off the path.If you use 2006 corvette gear,than use all 2006 parts.

BTW-It is 26 ft lbs on cam gear and 18 ft lbs on front cover etc.


My .02

Andy

Good information, thank you. By the sounds of things most camshaft companies aren't making cams with the single bolt hole just yet? That being said, I wouldn't have a choice in the matter I'd have to swap out the cam gear.

Where you lose me is the business about the dampner. Are you referring to the crank pulley, that is what I would typically call the dampner. IF the OEM piece came off, why couldn't that go back on? I'm not so much doubting, as much as I don't think I really followed what you were saying.
 

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Timing chain dampner/tensioner,2007 has this on the passenger side of the block right behind the front cover.The chain rides on it.

If you done alot of ls1's you would have never seen the dampner block(only on ls2).On 2007 single bolt cams they use a tensioner and no dampner block.


Just use the 2006 corvette stuff and youll be fine.


My prayers are with you if it is all wheel drive,factor in 3 more hours to do it right.
 

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1 OTHER TIP - Get a couple extra tork bits for the cam plate.You think the cam bolt is hard to remove,wait till you get to these four torx.

Sorry I missed that one earlier.

Andy
 

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Discussion Starter #11
1 OTHER TIP - Get a couple extra tork bits for the cam plate.You think the cam bolt is hard to remove,wait till you get to these four torx.

Sorry I missed that one earlier.

Andy
Oddly enough I breezed through that part. I've got some MAC torx bits that are pretty stout.
 

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Timing chain dampner/tensioner,2007 has this on the passenger side of the block right behind the front cover.The chain rides on it.

If you done alot of ls1's you would have never seen the dampner block(only on ls2).On 2007 single bolt cams they use a tensioner and no dampner block.


Just use the 2006 corvette stuff and youll be fine.


My prayers are with you if it is all wheel drive,factor in 3 more hours to do it right.

How does the AWD affect a cam swap? Want to know because I have a 2006 AWD.
 

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How does the AWD affect a cam swap? Want to know because I have a 2006 AWD.

It does not affect the cam swap unless you want to shim the oil pump for more pressure.

You cannot get the oil pump on and off easily without dropping the pan.You cannot get the pan down easily when you have a diff mounted to it.


We in Texas don't have ths problem since there are virtually no AWD here.

BTW-In 2006 you had 3 bolts in the cam so your ok.It is the 2007 awd that suck,because you have to pull the oil pump to do the job right!
 
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