I'd check driveline components - to me, that really doesnt sound like bearings or valvetrain, but it's tough to really hear it form a little computer speaker.. - does it totally go away when you let off the throttle? I once has a similar noise from a cracked flex plate under load. take the inspection cover down and see what you can see, also check U-joints too.
In case I missed it, does it make the noise while in idle sitting still? Sometimes you can use a piece of hose as a stethoscope and listen to different areas of the engine to help isolate the sound
I have inspected flex plate with boroscope and small inspection mirror. Turn engine a complete 720 but i do not see any cracks at all. I figure if it was drive line, I would feel a vibration under floor boards. u joints check out ok but I plan on removing drive line to inspect center support bearing assembly
Howabout supporting the rear end off the ground and running it up to 50 then have a buddy try to isolate the noise.
I had a noise I couldent figure out, ended up being an exsuast leak. Had a small crack in my exsaust manifold and got it welded up. Do you smell more emissions.. Sorry if that didn't help
If it was a knock from a bearing I would think it would be just about as loud at idle. It is too loud to not do it at idle. I had a 383 Mopar and it knocked the same at power and at idle. Does sound like loose flex plate bolts or there is a crack you cannot see. The crack could be at the bolt area at the engine.
This is what I have done since yesterday. I lifted Car on hoist and preformed a couple of test drives above 50 mph as following. Wheels hanging and then jack stands at rear. NO NOISE AT ALL !!! Well that eliminates any engine or flex plate issues. I spent a bit more time examining drive line center support and can it completely worn out. I will start by replacing bearing center support assembly and rechecking. I'll keep you men posted. Give me about two weeks ....
Any details you could share on your driveshaft overhaul would be appreciated. I need to do my '67 at some point.
Most excellent video. Thanks for posting. Are you aware of the phasing requirement in the manual for the front and rear shaft sections?
Sorry it took so long to get back to you. It's been a heck of a week... The phasing I'm talking about is different than what the Cat shows above. In the Service Manual (attached) the Riviera is the 49000 series. Go to page 40-47 of the manual (page 11 of the .pdf) and look at figure 40-78 "Propellor Shaft Phasing". They show a required 67-1/2 degree angle between the front yoke relative to the center splined yoke assembly. From what I've read on the AACA forum, if you don't put that angle in, you will have vibrations.
