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Hi, where can I get a timing belt (chain) for a 1975 Chev. Nova. 250 eng. L-6 4.1L? While replacing the belt I'm sure I will need a few other parts to do a complete job if anyone has that info. perfect, if not the place or places where I could buy this parts. I'm sure once contacted they will advice further. Thanks.
 

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It has neither a chain or a belt. It is a gear drive. The cam gear is pressed on and hard to change without removing the cam. I have had good luck using a pry bar on the fuel pump lobe to install the gear with the cam installed. Usually the gears will last as long as the bearings and rings do.
 

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Thought you might like a preview of what you'll be looking at...

Here's the gear that fits on the end of the camshaft:


And here's the one that's on the crankshaft:


The gear on the crankshaft rarely needs to be replaced. The fiber teeth on the camshaft gear are almost always the source of timing problems. You'll also need a timing cover gasket kit...

BTW: the photos are courtesy of RockAuto (www.rockauto.com), which is a pretty good place to buy parts on-line. I've bought quite a few parts from them and have always been satisfied with the price and quality.
 

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The replacement gears will be metal. The phenolic gear is hard to find.

Any local parts store should be about to supply the parts needed.

Al
 

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Discussion Starter #5
Great Info.

Great information it will help a lot. Not being a mechanic I had a totally different idea of what I needed based on what I was told by the mechanic. Another member of the forum informed me than in fact what I need is a gear drive and the cam gear is pressed on etc, etc. Most thankfull for your help. Any other suggestions as to what is needed to fully complete the job like oil seals or else will be welcome, Thanks once again.
 

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Discussion Starter #7
Reply.

What makes you believe you need new timing gears?
Without a doubt after over a month trying to find the problem with my Nova finally after different test and check ups one mechanic finally narrowed the problem to a timing issue. Posibilities as the what was causing the overheating, lack of power (knocking), fuel consumption raw and high, rough idle when cold etc. were slowly eliminated with different test. Take care.
 

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Discussion Starter #8
Reply.

It has neither a chain or a belt. It is a gear drive. The cam gear is pressed on and hard to change without removing the cam. I have had good luck using a pry bar on the fuel pump lobe to install the gear with the cam installed. Usually the gears will last as long as the bearings and rings do.
Your initial responce was key in guiding me in the correct direction in looking for the part needed to resolve my problem. By the way, while doing this job will the mechanic have easy access to replacing the original oil pump. Still works ok but the pressure after so many years can not be the best, I know the oil pan has to be removed to install a new oil pump but I don't know if it is necessary in the changing of the gears. My mechanic is out of town and this question just came to me now.. Thanks for your help.
 

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A few other tips from having done this job many times.

* Buy good quality gears made in the US
* Buy the proper gear pullers and get a good pry bar or two
* Be VERY careful removing the cam gear so you dont accidentally pull the cam out or damage the bearings. That cam can be a royal pain to get back into its bore.
* Make sure you understand the concept of timing the engine
* The bottom of the timing cover bolts to the oil pan. Carefully remove it so as not to damage the front ends of the oil pan gasket.
 

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Discussion Starter #12
Thanks.

A few other tips from having done this job many times.

* Buy good quality gears made in the US
* Buy the proper gear pullers and get a good pry bar or two
* Be VERY careful removing the cam gear so you dont accidentally pull the cam out or damage the bearings. That cam can be a royal pain to get back into its bore.
* Make sure you understand the concept of timing the engine
* The bottom of the timing cover bolts to the oil pan. Carefully remove it so as not to damage the front ends of the oil pan gasket.
Sorry for my slow responce, but greatfull for your advise. I trust that my mechanic will do the right thing. He intends to pull the engine out to be able to work freely and hopefully he will do a good job.
 

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Discussion Starter #13
Thanks.



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The replacement gears will be metal. The phenolic gear is hard to find.

Any local parts store should be about to supply the parts needed.

Al
I just bought the parts needed at Napa. Thanks once again for your help. you were as others in the forum most helpfull. Now I will just have to cross my fingers and hope that my mechanic will do a good job. As it turned out the easiest thing was to find the parts.
 

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Metal would be the way to go....

I wouldnt use any Synthetic metal/materials in that area of the motor....

But thats me....
 

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I have an nos phenolic gear should I use a metal one instead
thank you
schwabie
In tech school years ago they told us the "plastic" gears were used to "reduce engine noise", or so the manufactures said. It was likely a cost-cutting endeavor. If what you have is correct for your motor go ahead and use it. The service life of those things is likely far beyond what the motor will actually be put through these days. On the flip-side if you do not mind spending the money, ditch the "plastic" crap and get metal gears.
 

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In tech school years ago they told us the "plastic" gears were used to "reduce engine noise", or so the manufactures said. It was likely a cost-cutting endeavor. If what you have is correct for your motor go ahead and use it. The service life of those things is likely far beyond what the motor will actually be put through these days. On the flip-side if you do not mind spending the money, ditch the "plastic" crap and get metal gears.
I heard that too. They are made out of some kinda bakelite substance. A friend of mine was driving his nova on the freeway and the car just went completely dead. Turns out he had stripped the teath off.

-Tom
 

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V8's used a nylon covered aluminum cam gear to reduce noise too. It could not have been cheaper to produce than a steel gear so it may have had some merit.
 
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