How to align crank and cam after stripped timing gear?

[TonyO454]

It’s on a 93 3500 454,plastic cam gear stripped on shutoff,truck was not restarted, pulled valve covers and there were no loose rockers so I guess I’m gonna throw on a new timing chain clean the oil pan out and hope for the best only thing is how do I rotate and align the cam and crank without damaging the valve train? Any help would be greatly appreciated!!

 

[kennythewelder]

Everything has to he set to TDC compression stroke. IDT that the valve clearance is so close that the valves will hit the top of thw pistons when you rotate the cam shaft. This is done with a spanner wrench that had a bar with 2 pegs that lock into the holes in the cam gear. There should be several videos on you tube that show this.

 

[TonyO454]

Everything has to he set to TDC compression stroke. IDT that the valve clearance is so close that the valves will hit the top of thw pistons when you rotate the cam shaft. This is done with a spanner wrench that had a bar with 2 pegs that lock into the holes in the cam gear. There should be several videos on you tube that show this.

Thank you for your response, I understand tdc I was just worried if I rotate the crank or the cam gear with them being way out of line that I’d damage the valves or bend pushrods

 

[PlayingWithTBI]

I was just worried if I rotate the crank or the cam gear with them being way out of line that I’d damage the valves or bend pushrods

The only other answer is to loosen all of the rocker arms, align the timing marks on the cam and crank, install the chain, then torque the rockers again.

 

[skylark]

The only other answer is to loosen all of the rocker arms, align the timing marks on the cam and crank, install the chain, then torque the rockers again.

I would also air check the cylinders using the hose from a compression tester to verify that you don't have air coming out of the intake or exhaust.

 

[TonyO454]

Awesome.....thank you for your replies I’ll post back and let you know how it goes.

 

[LC2NLS6]

Don't remove the distributor. Doesn't have to be tdc comtpression, any tdc will work because the cam has a pin that only goes on one way. Probably loosen rockers, and try to spin cam to align the dots on install. Pull spark plugs too to make turning crank over easier by hand to get to 0 indicated to line up the dots. It won't be adjustable so it'll probably just work close enough to 0. I bet you bent valves, but she'll run until it snaps one off.

 

[TonyO454]

Don't remove the distributor. Doesn't have to be tdc comtpression, any tdc will work because the cam has a pin that only goes on one way. Probably loosen rockers, and try to spin cam to align the dots on install. Pull spark plugs too to make turning crank over easier by hand to get to 0 indicated to line up the dots. It won't be adjustable so it'll probably just work close enough to 0. I bet you bent valves, but she'll run until it snaps one off.

 

[TonyO454]

I’m afraid some of the valves are bent as well I have pulled the plugs and valve covers getting ready to pull the oil pan. I was told to look for loose rockers and had none so I’m crossing my fingers but I usually don’t get so lucky

 

[skylark]

I’m afraid some of the valves are bent as well I have pulled the plugs and valve covers getting ready to pull the oil pan. I was told to look for loose rockers and had none so I’m crossing my fingers but I usually don’t get so lucky

The 454 typically isn't an interference engine unless it isn't stock.