timing chain
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timing chain
The engine I just took out is a 1996. I put in a 2007. The 1996 doesn't have a timing chain. It just has two large gears. I didn't think they used those that long ago...
Jason
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Re: timing chain
Gear Drives are nothing new. Big engines have used them for decades and Chevy Guys put them in their engines so they make more noise and scare all the cats out of the neighborhood.
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Re: timing chain
Many straight in line 6 cyls like gm 230,250,292 and Ford 300 used them for a long time starting maybe mid 60 ish from what I remember in my other lifetime selling parts.
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Re: timing chain
I know they have been used for some time. I meant specifically in the gm 6.5 TD.
Jason
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Re: timing chain
The 2008 TM's show a timing chain still being used. There must be a story to that engine of yours.
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Re: timing chain
Date code is J126
This motor ran great. It was pressurizing the coolant system, so I bought a 2007 motor to put in. The water pump whines on the replacement, so I took the old one off before I did the work to the newer one to see how easy it will be.
What is the plunger for in the center of the upper gear?
Jason
This motor ran great. It was pressurizing the coolant system, so I bought a 2007 motor to put in. The water pump whines on the replacement, so I took the old one off before I did the work to the newer one to see how easy it will be.
What is the plunger for in the center of the upper gear?
Jason
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Re: timing chain
The timing chain is only seen and accessible if you remove the front housing...the timing gear set up
Is stock in all 6.2-6.5 TD motors.
Is stock in all 6.2-6.5 TD motors.
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Re: timing chain
There is a strong spring behind that button. It controls thrust of the gear.
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Re: timing chain
As Steve says...
Those gears are normal, and have a timing dot on each one.
Chain and its gears are under that cover....lower end of chain goes to crank.
Those gears are normal, and have a timing dot on each one.
Chain and its gears are under that cover....lower end of chain goes to crank.
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Re: timing chain
Just to add, the lower of those two large gears is attached to the cam shaft and is placed in front of the upper timing chain sprocket.
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Re: timing chain
When gears are used as these are, the rotation is reversed so if you were to use gears as timing gears between the crankshaft and camshaft, they can't touch each other. they need a separate gear(s) to carry the movement between them.
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Re: timing chain
The gear on the crankshaft drives a chain which drives the gear on the camshaft at a ratio of 2:1 in the same rotational direction.
Also on the camshaft is another gear in front of the chain driven one which drives the gear used to drive the injection pump. The injection pump is reverse rotation as seen in Jason's photo.
Some engine builders opt to select gear drives over chains for the camshaft in order to avoid eventual "chain stretch". These gear drives always use an intermediate/idler gear on either one side or an extra set on both sides to maintain correct rotation.
Also on the camshaft is another gear in front of the chain driven one which drives the gear used to drive the injection pump. The injection pump is reverse rotation as seen in Jason's photo.
Some engine builders opt to select gear drives over chains for the camshaft in order to avoid eventual "chain stretch". These gear drives always use an intermediate/idler gear on either one side or an extra set on both sides to maintain correct rotation.
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