Chevy Small Block Knocking and Popping.

[Boulky12]

How's it going fellaz. Yesterday I purchased a 78 longbed with a 350 and 350 tranny.

When I first started the truck up, in Park, there was a Very loud knock that sounded like it was coming from the back of the motor, flywheel area.

When I put the truck in drive and drove it around the block the knocking went completely away, but when I'm switching gears from Park to Reverse to Drive there's a very loud popping noise right before she starts rolling.

I drove the truck home 30 min away with no issues(not even knocking) so at this point I'm thinking its either a cracked flywheel or somethings up with the trans.

I havent crawled under her yet to see if theres anything obvious but ill let you guys know when I do so.

Really Interested in what you guys think about the popping because I couldn't find anything on that. Any help is appreciated. Thanks!

Here's some pics.. I think its a nice project for $500.

[Mike P]

Symptoms sound like a cracked flex plate. Personally I wouldn't drive it until you get a chance to check (i.e. puling the tranny back and dropping the plate out). I have seen an instance where the plate finally gave out and took the convertor and front pump with it.

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[Boulky12]

Symptoms sound like a cracked flex plate. Personally I wouldn't drive it until you get a chance to check (i.e. puling the tranny back and dropping the plate out). I have seen an instance where the plate finally gave out and took the convertor and front pump with it.

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Well than its a good thing I already drove her home. haah. I hope its just the flexplate. I appreciate your input.

[40FordDeluxe]

I agree with Mike. It really sounds like a broken or cracked flex plate. Man, for $500, you can't go wrong. From the looks of the bed, guys up here would pay that or more just for the bed!

[Boulky12]

I agree with Mike. It really sounds like a broken or cracked flex plate. Man, for $500, you can't go wrong. From the looks of the bed, guys up here would pay that or more just for the bed!

I'm hoping it is because I just had to swap the one in my last project, so its still fresh in my mind. And yea for the price I wasnt gonna pass it up. Thanks bud!

[rspears]

Very cool old truck, and came with a set of classic Cragar's, too! Hoping it's an easy flex plate fix for you, and welcome to the forum!

[firebird77clone]

Any truck that moves and stops under its own power is worth $800, so you are already up $300!

But seriously, yes, good steel for the money.