Rattling Noise between 2500-3500 rpm

perholmen · #1 (**permalink**) 05-19-2008, 11:16 AM

I have a strange metallic rattling noise which is fairly loud when accelerating on my 1972 Super Giulia . I've had the car up on a lift, with the wheels hanging freely and then driving though 1, 2nd and 3rd gear and the noise is not as pronounced as when the car has all 4 wheels on the ground.

I am a bit pouzzled as to what it could be - it's pretty difficult to hang out the window at the given revs to hear where the sound comes from, but it sounds more like coming from underneath the car than from the motor area.

Ideas???

**Bill S** · #2 (**permalink**) 05-22-2008, 09:31 AM

One thing you may want to check is the large nut that attaches the yoke to the output shaft of the transmission. They've been known to work loose and even fall off, bouncing around inside the yoke!

perholmen · #3 (**permalink**) 05-22-2008, 12:45 PM

Thanks for your input - the yoke?! IS that just where the shaft exists from the transmission before the propelleor shaft meets the central support??

Need to take a look under the car when I get it home.

**Bill S** · #4 (**permalink**) 05-22-2008, 03:08 PM

I don't know if it's the correct term or not, but yes, that thing that the giubo (donut) is bolted to. The nut that holds it in is accessed by removing the drive shaft and requires a large deep socket to tighten it down. It's the only nut on an Alfa that I use an impact wrench to tighten. You might be able to see if it's loosened without removing the drive shaft by seeing if the yoke has any in-and-out play. Keep us posted.