Hello everyone I'm new to forums. I have a 2001 f250 I work on my own trucks. This is my second 7.3. Both have the zf5 6 speed manual transmissions. I just replaced the high pressure oil pump and then my rear end went out. I replaced it with a brand new 1995 ring and pin. So now my problem is a grinding sound/ winning whistle from the top of my transmission!! Please help me fix Frankenstein!!
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Good evening, As others have noted specific analysis by the noise descriptions of others is difficult in person and even more so passed on into this media.
So, this mostly deaf old man will throw a bit his career experiences in, some technical and some from when he could hear extraordinary well.
Like others I would opine that the noises you describe are more likely sourced in the recently rebuilt rear differential. If so, below applies
Typical observers noise descriptions
Typical "Whine".... A high pitch high frequency noise whose amplitude is modulated by a forcing factor like speed.
Bearing Defect Noise .... A roar that sounds like buckshot sloshing in a coffee can, also modulated by the forcing factor of fundamental speed.
Note... just a descriptive way of saying the faster one goes the louder it is, until the human ear can't discern anything frequency specific, just max volume.
Technical
A speed modulated "whine" is typically produced by the interactive meshing of a driving gear with a driven gear. The "whine" is more than just noise, it is energy at the Gear Mesh frequency.
Design strategies to reduce this GMF energy are in the adjustment of driving and driven gears to each other in the applicable planes for the gear combination type.
It is an easily mathmatically quantified external diagnostic to make if one has sophisticated vibration analysis equipment capable generating waveform and spectra for confirmation.
Few typical automotive users have that equipment or the training and experience to make a specific gear defect analysis. In my business it's a common task in industrial drive line gear boxes that have multiple gear sets in one big box. Often with a bearing set or sets that can have their own bearing defect frequencies.
This differential application has one gear mesh, the R&P, so they can just go right to it. Let's do that
Most likely the root cause is incorrect engagement of the R&P and possibly a pinion bearing improperly adjusted in combination.
Jim
