For all those with that "mystery rattle".

[86SILVERADO]

Well,

I was breaking in the new cam in my REBUILT 305!

LOL.......I like 20 MPG remember?... and I heard this rattle which I had been hearing through the 305 before I did the re-build, the 350 that was in there for a bit and is now in the dump, and two different transmissions. I am kind of one with all the grinds and growls, bumps and rattles that just seem to go with these old trucks but I do have a pretty good idea of what they come from and so they never get to me much. This noise had been bugging me for a while though because it sounded alot like the flexplate rattling against the dust cover or a loose converter bolt or something and I kept checking but found nothing amiss down there. Well while I was breaking in the cam I was sitting in the drive in neutral with the door open and wouldn't you know it but there is this sound again consistently at 1700 rpms. I put my head down alongside the cab to listen and out of the corner of my eye I saw the gas tank filler door vibrating. I let the throttle drop down to 1500 and sure enough it stopped. back up at 1700 there it was again. So before you go replacing your next torque converter take a look at the filler door and you may end up saving yourself some time and $$$.