First, let me say I've been absent for quite some time...more on that below.

I need some help from those more well-versed than I. My '56 T-Bird developed a strange "rattle", and I'm having a helluva time nailing it down. Here's what I can tell you from my observations:

• Most noticeable at idle (700 RPM+/-), up to around 1000 RPM
• It is not consistent, or directly proportional to engine RPM's (like bottom-end or valve train noise)
• It makes the noise in & out of gear, but doesn't increase/decrease with speed.
• No weird noises/clunking when shifting in/out of gear like an engine mount/support.
• The transmission shifts very well, nice & firm, with immediate engagement in all ranges.
• The engine/tranny have not been separated in decades.

The best description of the sound that I can give is that of a single rock bouncing around in a tumbler. I haven't put it up in the air yet to pull the dust cover off the bottom of the bell housing, but that's where I plan to start. I am thinking that maybe something is loose or broken, and rattling around randomly in there.

Has anyone ever experienced something like this? I greatly appreciate any advice.



Regarding my absence, I've been focusing on selling the last few of my Dad's cars and trimming down the spare parts cache. Also, spent last winter/spring giving my '63 Cadillac the once over...obviously not Y-Block related but those of you that know me, know I don't discriminate. Here's a couple quick pics...





Todd in Central California...about half way between Fresno and Sacramento

1956 Thunderbird - 1960 F-100 - 1961 Starliner - 1961 Imperial

Todd

One thing you might want to check are the "ears" thar are rivited onto the flexplate. These are known to crack and make random sounds. Pete

Thanks Pete...I'll have a look when I pull off the cover.

Todd in Central California...about half way between Fresno and Sacramento

1956 Thunderbird - 1960 F-100 - 1961 Starliner - 1961 Imperial

Yep, I think Pete nailed it.
BigRedTodd, you're sound diagnostics is what gives it away for me. Been there, and that is JUST what it sounded like.

       A  L  A  N   F  R  A  K  E  S   ~  Tulsa, OK    

I've been there too. In my case it was loose rivets at the ears. I replaced the old style flex plate with a new 57 solid flex plate.

Appreciate the help guys. I try to be as detailed as I can with the description, and it looks like it helped

Without having them side by side, are there any fitment issues with swapping out the riveted flex plate for the solid ('57-up) type? Looks like MAC's has the later flexplates for $55, which will keep this relatively cheap provided this is the problem.


My first (gut) reaction was to shop for a late C4, buy a Mumert bellhousiing kit, and just swap it out. But given the fact that my tranny works like a champ, I think I'll put that $1500 improvement off. For around $150 total parts, hardware, and beer I'll just knock it out. Similar amount of labor, but I give myself a deal on that.

I'll keep my fingers crossed.

Again, thanks for the experienced input. It is appreciated.

Todd in Central California...about half way between Fresno and Sacramento

1956 Thunderbird - 1960 F-100 - 1961 Starliner - 1961 Imperial

I've got one like in the picture off my 55. Let me know if you want it, I'm in Modesto.

Don Wigle

Thanks Don. That would be great, as I'm essentially in Modesto also (Riverbank)...

I'm gonna put the car up in the air this weekend, or early next week to take a look. Provided this is the issue, I'll shoot you a message and we'll get together.

Todd

Todd in Central California...about half way between Fresno and Sacramento

1956 Thunderbird - 1960 F-100 - 1961 Starliner - 1961 Imperial

Todd,

Check with Tim Mc and see if a later one would work. They are probably stronger and i think the bell was the same, so it should work.

Frank/Rebop

Bristol, In ( by Elkhart)