Help Identify - Ford 5.4L Transmission Area Metallic Noise (sounds like sheet metal against a fan)

[um1990]

Can anyone help me identify this odd sound from bell housing area of 2008 5.4L Ford (Expedition) ?

Transmission seems fine, pulls heavy trailers fine, no stutters, etc. This sound started a month or so ago.

Does not appear to be heat shields or catalytic converters (first thing checked)

Had Mechanic check and could not find issue - Said Flexplate looks ok, bolts tight, removed/replaced inspection plate, transmission fluid looks fine, etc. He said "may need transmission"

It actually gets much worse sounding when on an incline (pointed uphill like on boat launch) (?), but appears to be no performance affects whatsoever. It mostly quiets down when driving (but still happens in P, N, D, R, etc)

 

[Plati]

Is it that vibration resonance absorbing damper "thingy" that is hanging off the muffler system? They tend to sort of 1/2 fall off and make noise

https://www.expeditionforum.com/thr...n-the-bottom-of-my-vehicle.38260/#post-332697

 

[stamp11127]

When flexplates fail they sound like nuts in a can and you think the trans is going to fall out. That sounds more like a fan blade just catching something. Check any heat shields in the area for looseness. Double check the fan blade edges and inside of the fan shroud up front. Also inspect the exhaust system in that area. Initially it sounded like a loose baffle.

One thing about being in your 60's is I've heard that sound before. Its........

If you have a scrap piece of wood that you could use as a poor mans stethoscope

 

[bobmbx]

Rubber mallet time. Start whacking everything.

 

[um1990]

Thanks everyone, for your thoughts.

After having 3 shops look at it, the rural transmission shop finally figured it out.

It was the Starter! Maine rust kills stuff, and it was apparently victim to it. Apparently the return spring was weakened, so the pinion/bendix was touching the flexplate off and on.

New Starter, Problem Solved.

First shop said "probably need a new Transmission", second said "Need new Flexplate" - Not great prospects, so got a 3rd opinion.

I'd usually do a job like that myself, but decided since the shop was great & figured out the issue, paid them to do the job.

 

[jeff kushner]

I don't have sound on my work computer but as Stamp says....isolate it will a piece of hose or yes, dry wood transmits sound as well. You can do this part yourself but I'd chock wheels etc before climbing under any running truck.

My dad used a deaf mechanic when I was a boy. Dad was an acoustical engineer so he knew very well how the mechanic was able to nail the issue every time.
Granted, cars were much less complex but the lesson holds true.



jeff