[RallyRacer]

Originally Posted by amc49

What do you do about the gear whine that occurs on many 4F27E from gear/bearing wear in the transfer gears to differential? No kit on planet addresses that issue. Just curious, one of those gears has a nut that torques at like 450 ft.lbs. of torque. You don't just do that on the old garage workbench. Will require special holding fixtures just to avoid damaging parts while torqueing that nut up. When bearing below that nut loses preload, the gear can tilt out of plane leading to abnormal gear teeth wear, causing the whine. Close to a similar common problem in the old Tempo/Excort ATX trans. Ford engineered trans to wear out in a difficult way to fix just like many other of their recent efforts.

Gear whine from a 4F27E, OK? I have never heard of that problem or experienced it so I can't help you there.

Just curious, one of those gears has a nut that torques at like 450 ft.lbs. of torque. You don't just do that on the old garage workbench.

Yes, I do those on a work bench in a garage. It's all about having the right tools and knowing what you are doing. The input drive gear nut uses a special socket (in the picture above) and is not tightened to 450ft/lbs but 332ft/lbs or 450Nm, while another special tool (final input drive gear holding tool) is holding the gear, and special tool (trans bench mounting bracket) holds the trans to a work bench.
There is a one time use collapsible spacer in that assembly that when not replaced can cause the problem you are describing. The Bearing preload is important when replacing the final drive input gear.

The 4F27E is bulletproof when built correctly so any issues with gear whine, etc. after a rebuild are the fault of an incompetent tech or not following the procedures like the on below.