LT1/LT4 Timing Chain Installation *HELP*
Thread Starter
7th Gear
Joined: Mar 2017
Posts: 7
Likes: 0
LT1/LT4 Timing Chain Installation *HELP*
OK, so I decided to do a dumb thing 
and disassembled my timing cover in my 1996 LT4. Part of that included taking off the cam sprocket, as well as the timing chain while forgetting to line up the crank/cam timing marks prior to removing the chain!
So, since the LT4 has the long dowel pin on the cam, I figured that since I didn't move the crank or the cam, I would be OK to put the sprocket and timing chain on as they were before I removed them and carry on.
That was a bad assumption. The '96 FSM (which I should mention I got after I made the mistake otherwise I wouldn't be in this mess) makes it very simple: 1.) Install Cam Sprocket 2.) Install Timing Chain.
The only thing is I cannot get this damn thing on! The crank gear is at approx 10 o clock and when I put the cam sprocket on in the correct place where the dowel pin is in and the bolts line up properly, it is at approx 10-11 o clock. The only issue is that I cannot get the chain on.
Now that I made the dumb mistake, how can I recover and line up both the crank and cam gears properly and get this timing chain on?
Thanks in advance.
and disassembled my timing cover in my 1996 LT4. Part of that included taking off the cam sprocket, as well as the timing chain while forgetting to line up the crank/cam timing marks prior to removing the chain!So, since the LT4 has the long dowel pin on the cam, I figured that since I didn't move the crank or the cam, I would be OK to put the sprocket and timing chain on as they were before I removed them and carry on.
That was a bad assumption. The '96 FSM (which I should mention I got after I made the mistake otherwise I wouldn't be in this mess) makes it very simple: 1.) Install Cam Sprocket 2.) Install Timing Chain.
The only thing is I cannot get this damn thing on! The crank gear is at approx 10 o clock and when I put the cam sprocket on in the correct place where the dowel pin is in and the bolts line up properly, it is at approx 10-11 o clock. The only issue is that I cannot get the chain on.
Now that I made the dumb mistake, how can I recover and line up both the crank and cam gears properly and get this timing chain on?
Thanks in advance.
Last edited by mikedirntrulez; Apr 18, 2017 at 12:22 AM.
Instructor
Joined: Feb 2015
Posts: 234
Likes: 20
From: Stuart Florida
Don't forget that the crank rotates twice every time the cam rotates once, so you run the risk of being 180 degrees off. I would loosen rockers to allow free cam rotation. Then, loosen plugs to allow free crank rotation,remove cylinder #1 plug, Put transmission in neutral, hand brake on, if a manual. Rotate the crank until you feel compression "pop" in cylinder #1, with a fingertip plugging plug hole #1. (this is how I did it, crude but it works) This tells you that you are TDC in #1. Or you can put compression tester in #1 cylinder until you see max compression and crank dot is at TDC. At TDC piston #1 is at top of compression stroke and both valves are closed, creating max compression. Leave crank at TDC. Rotate cam to TDC, install timing chain. I used this method with my cam swap and it worked fine for a backysrd mechanic. There are more technical ways.
Le Mans Master
Joined: Aug 1999
Posts: 7,339
Likes: 137
From: WilkesBarre PA
Like stated first remove the nuts from the rockers, then you can rotate the cam with the gear so the dot is at the 6-oclock position by hand. Then rotate the crank so the dot on the gear is at 12-oclock. Install the chain then put one or two bolts in the gear. Turn the motor over a few times making sure the dots line up at the 12 and 6 points. If so put all the bolts in with locktight. If they are the stock nonadjustable LT4 rockers just torque down the nuts. Make sure you reinstall the reluctor ring that goes on the lower gear before the cover.
