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Premium Member
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Discussion Starter #1
Trying to put a new timing chain in my
70-455. After removing the fuel pump eccentric I cant get it to budge. Is there anything else Holding the gear on? I didn't want to use too much force till I get some advice.
 

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64-67 Expert
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You need to walk off both gears at the same time, crank and cam. Two small breaker bars work fine. I've never needed a puller. It's a somewhat tight fit.
 

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Discussion Starter #3
Still no luck. Cut the chain off, crank gear slid right off but the cam gear won't budge. Very little room between gear and block on this 455, not enough to get the jaws of my puller behind it without grinding them way down. Teeth aren't bad, I may just leave it on and put the new chain and bottom gear on. I'd still like to know why I can't get this gear off, first time I've done this. I'm sure I could get it off with some big time pressure but I don't want to take a chance of damaging the camshaft or bearings, and the gear still appears to be serviceable.
 

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The old gear will wear the new chain out in short time, plus you'll probably not be able to get it on anyway. I've always been able to use a pry bar on each side of the gear and wiggle it left to right to get it off. It may be stuck good, but it should come off. You might want to maybe apply some heat to the gear around the outside of were it fits over the cam then pry.
 

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What Rukee said. A fresh chain will not go on with the cam gear in place....not enough slop in the chain. You must replace that cam gear. Try some rust penetrant, gentle tapping, and walking it off with two opposed prybars. It will come.
 

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I've had to fight with them myself. Sliding off the keyway is the problem. Here is a consideration you might try. Look at your cam/gears to see if this might work.:thumbsup:

Put the bolt back into the cam to protect the threads. You will need 2 chisels or big screw drivers that you can wedge between the cam gear and block, something you can tap in to put some pressure on them - not killer pressure, just a reasonable amount (never heard of a block cracking from this, but just be careful). Then I would find a big socket that will go over the cam bolt and be large enough in diameter to still fit within the inside diameter of the cam gear.

With some pressure being applied to the cam gear on each side from your "wedge" you tapped in, give a couple good solid hits to the socket. You are trying to "shock" the gear loose off the keyway using the wedge to force it forward while hitting the cam to force it backward. After a couple good hits, if it still does not move, tap the "wedges" in a little tighter. Hit the socket again with some good hits. I would also hit the cam gear a few good times on the teeth edge where the wedges are not at. This may rock the gear just enough while they are on the "wedges."

If no luck, move the "wedges" 90 degrees to another location (or turn the cam 90 degrees) and repeat. Sometimes you have to rotate your "wedges" at different points on the gear to get it loose by applying pressure at other points on the gear. Repeat above.

If you put an uneven pressure on one side of the cam gear or the other, you will be tilting the gear and this will only make it more difficult for the gear to pop off. So it is always best to use identical type "wedges" to give you an idea that you are getting the same kind of even pressure.

You might even consider a little heat from a propane torch by applying heat around the gear just outside of the camshaft while you have your wedges inserted. You want to keep the camshaft cool and heat in a circular motion the metal adjacent to the cam. You are trying to expand the metal just a hair. Then give the camshaft a pop to break it loose from the gear.

A puller should work -although I have never used one on a cam gear, just a lot of prying. Have you tried your local auto store to see if they may have a puller that would work? My parts store has free loaner tools that you simply put a deposit on and get refunded once you return the tool. You might find one large enough to grab the outside of the gear.
 

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Discussion Starter #9
Great advice Jim, thank you. I have a puller big enough but there's so little room between the gear and the block the arms won't fit. I've borrowed tools from advance auto before I might see what kind of pullers they have and use a little heat when I get back in town. It's gotta come off, one way or another.
 

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Discussion Starter #10
Finally found the right style puller and the cam gear pulled right off. Thanks everyone for your advice.
 

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Finally found the right style puller and the cam gear pulled right off. Thanks everyone for your advice.
Excellent!:thumbsup: They can be stubborn. Make sure you check your crank balancer if it is the original 1970 piece. The rubber can dry rot/crack and the outer ring can slip/rotate or get off center. The timing cover seal can also dry out over time and become very hard -which wears/cuts into the hub. You can develop a leak here because of the wear. If its original, since you have it off, you might consider replacing it with a new after market one for piece of mind.:smile2:
 

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Discussion Starter #12
Always appreciate the advice Jim. Most everything in this car has been replaced or modified. Its a 68 with a 70-455, actually a Butler 474. The balancer looks fairly new and the Felpro gasket set contains a new seal. The more I learn about these Pontiac engines the more I discover how unique they are.
 
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