How to replace your crankshaft gear

This is something I did but I am sorry I did not make a video of it. If you look around you will find there is little or no information on how to replace the crankshaft gear on a cummins engine. First I will explain what I tried that did not work and how I got it to work.

What happen was my oil pump failed and a piece of it went in between crankshaft and cam gears and the gear turned on the crankshaft. So big problem, first I have to get the old gear off. This is what I was told and all I could find out. First cut the gear almost through to the crankshaft then use a chisel and hammer to split the gear. This does not work, I keep cutting closer and closer and I can tell you that gear is not going to split or spread enough to get it off. So I cut it 99% through on two sides and it finally broke off. Keep in mind this gear is put on with thermal expansion.

So I got the gear off now I need to put the new one back on. This is what I was told and all the info I could find and I have done this with small engines and it worked. WHAT NOT TO DO, take a toaster over set it next to your truck and turn the oven all the way up put the gear in side wait about one hour. Then use welding gloves and slide the gear on. If it does not go on tap on it with a block of wood and hammer.
 

What happen it went on about and stopped so I took my wood and hammer hit it a couple of times and it went about inch more and stopped. So now it is way on and is not going on or coming off. I am thinking I will have to buy another one and destroy this one. When the gear is all the way on you cant get behind it unless the crankshaft is out of the block. But way on I thought I would give a gear puller a try. I have used gear pullers countless times in my life and this is the first time I had the bolts sheer off. So with new bolts in hand and a big pipe to go over my breaker bar I gave it another try. I got to the point to where something was going to break and stopped.



Understanding the crankshaft gear

How the crankshaft gear works

If you don't know what thermal expansion is, it is when one part is heated to make it big enough to fit over the other part so when they are the same temperature they almost become one. Or this is the scientific explanation, Metal expands when heated. Length, surface area and volume will increase with temperature. The scientific term for this is thermal expansion. The degree of thermal expansion varies with different types of metal. Thermal expansion occurs because heat increases the vibrations of the atoms in the metal. Accounting for thermal expansion is essential when designing metallic structures.
I set down with total discussed, then about 30 seconds later I hear a big bang. It moved but I could not tell it had move so I did it one more time and waited again a big bang so I keep doing this. It took about 1 hour to get it off but it came off. This time I left the gear in the oven 2 hours and took the gear out of the oven and used a oxygen acetylene torch and heated it up more. Using my welding gloves the gear slipped on with ease and went where it was supposed to go. So the if gear is hot enough it will go right on, if the gear dose not go right on with ease the gear is not hot enough. Stop and make it hotter or the gear will cool and stay where it is at.
Click on this page I am going to explain what is involved in replacing the crankshaft gear.
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