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Ugh...my timing chain is slopped out


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I got the holding tool from Summit and it worked great ! thank you for the heads up on that. Looks like it has the original timing chain set in there, with at least 1 inch of slop on the one side of the chain. Maybe I'm tired I just came in from the garage , but I can't see any visible timing marks on these gears.  What is the best way to remove a broken bolt from the T stat water tube piece that sits on the timing cover I had one bolt that broke off on that water manifold piece. 3 am riv work gotta love it. 

 

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Good work getting to this point -- 2 observations:  (1) Nylon-toothed cam gear, so definitely worth the effort to get rid of that!  (2) I'm not a nailhead expert, but I see the "o" on the crank sprocket which is just to the right of 12 o'clock.  The corresponding cam gear mark looks to be the raised 'pointer' cast into the aluminum at about 12 o'clock.  If so, it looks like one more crankshaft revolution should bring them into alignment and have the distributor rotor pointing to #1 on the cap.

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6 minutes ago, 1963 Riv said:

Hi, I am new to this thread, and recently obtained a 63' Riviera with 401 Nailhead and i need to find a timing chain cover and having difficulty locating. And suggestions would be appreciated. 

Contact Tom Telesco on this forum.  Goes by Telriv. He has a shop in CT and speializes in Buucks.

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5 hours ago, EmTee said:

Good work getting to this point -- 2 observations:  (1) Nylon-toothed cam gear, so definitely worth the effort to get rid of that!  (2) I'm not a nailhead expert, but I see the "o" on the crank sprocket which is just to the right of 12 o'clock.  The corresponding cam gear mark looks to be the raised 'pointer' cast into the aluminum at about 12 o'clock.  If so, it looks like one more crankshaft revolution should bring them into alignment and have the distributor rotor pointing to #1 on the cap.

Ahhhhh ok, I missed that one on the crank gear altogether! thank you sir. Let me line these up and see how it looks. 

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Well I am cleaning up the front part of the engine, I have one bolt which broke off in the head for the T stat housing, should I weld this nut to it and try to back it out? or just grind it flat and try to drill it out with an ez out? what would you all suggest?

 

 

 

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I'd try the nut, but leave room to get penetrating oil into the threads.  Alternate head and penetrating oil while working the nut counterclockwise & clockwise until you get some movement.  Lather, rinse & repeat...  ;)

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An aside to the problem. My belief is that the bolt was TOO LONG to begin with & has bottomed out. In this area is not prone to galvanic corrosion because the steel bolt & cast iron will not usually corrode. After the nut is welded on the broken bolt will transfer heat into the head. At this point try rocking the nut back & forth with an open end wrench. IF you can get it to move even very little hit with penetrate while still warm so hopefully some of it will wick into the threads & try again. It may have to heated & cooled/sprayed a few times, but eventually will soak into the threads to make the removal process a success.  This is a much better way for a novice to try than trying to drill & tap in my experience.

 

GOOD LUCK!!!!

 

Tom T. 

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7 hours ago, telriv said:

My belief is that the bolt was TOO LONG to begin with & has bottomed out.

 

I ran into the same issue when I changed the thermostat in my Riviera.  It was weeping coolant and someone previous just kept tightening the bolt beyond when it bottomed-out.  It snapped almost immediately when I tried removing it.  Fortunately, as with yours, there was enough exposed to allow me to get a bite with vicegrips.  I sprayed penetrating oil and worked it back and forth until I was able to get it to back out of the hole -- whew!  When I checked the bolt length and depth of the hole it was too long . I replaced it with one 1/8" shorter and no leak...

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  • 1 month later...
On 7/26/2019 at 4:38 AM, Hearse said:

The guy at Centerville Auto told me to turn the balancer to check for timing chain slop, I thought I had none but it turns out I can turn the crank a good 1.5 inches forward or back before the distributor rotor moves. I'm guessing it's the original plastic gear chain set. It could be an inch to an inch and a quarter of play before the distributor rotor moves but I know its too much . 

Soo...lol , any tips or tricks for doing this nailhead chain set? I've done hundreds of chains sets just never on a nailhead engine. I'm excited now that I know this may contribute to the weird things that have been happening lately. 

Any chain recommendations ? I'm not going to race this and neither is my dad. Just cruise it with the occasional throttle mash. Thank you for your thoughts once again . 

 

So, I'm repainting my front pulleys and decided to check for chain slack as you did.

I re-installed two balancer/pulley bolts and with a long bar between them I couldn't rotate the balancer at all.

But my guns are of small caliber - so maybe I'm doing something wrong?

Edited by PWB (see edit history)
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12 hours ago, RivNut said:

Try a longer pry bar.  Having the transmission in Park make a difference?

 

Yes sir, had the ol' gal in neutral.

 

This balancer is tighter than a dead cats' a**.

 

Hmmm....

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Must be that 10.25:1 compression ratio is now closer to 10.5:1.  You need to get out on the Interstate and "blow the slugs out" as my grandfather used to say!  ;)

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  • 3 weeks later...

I don’t own a nailhead Buick. Since that engine design was last made in 1966, I’d like to ask a novice question. Just where is a new timing chain sourced from these days?

 

A few years ago, we bought square drive chain for our scheduled machinery overhaul from a vendor who sourced the chain from China (which we were not aware of.) In a very short time after installation, we were experiencing drive failures and jams because the chain had stretched like salt water taffy. We took the links to a lab and found that, while they were the correct steel analysis we specified, they were not heat treated. Just formed and left in the fully annealed condition. Testing of our spares in inventory was the same. Evidently, China does not heat treat much of what they make. After that, we added a hardness specification and yield & tensile test results documentation to our specs. Then we had no more problems.

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  • 5 weeks later...

Thought you guys might get a kick out of this:

 

I pulled off my fuel pump to finish its half way painted self from the factory. Two easy bolts. Time to update the original fuel hoses also. 

Then found out I could see just about all of my timing chain with a borescope. Heck I could even pull on the chain with my finger to not find any slop.

I'm assuming its original and it sure goes to prove the years alone don't cause these plastic models to crack up. 

 

 

 

Chain 1.jpg

Chain 2.jpg

Chain 3.jpg

Chain 4.jpg

Edited by PWB (see edit history)
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I was able to do likewise (except checking chain tension) by removing the distributor (only one bolt!).  My cam gear also looked good (no visible cracks).  I do plan to change it soon, however.

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