2002 Ford Ranger 4.0 L SOHC 5 speed manual transmission
Whirring noise at low speed, low rpm, most pronounced in lower gears, mostly when starting in 2nd, all only when clutch is engaged and truck is moving. Happens in 3rd and 4th with a load or bogged, but most pronounced when moving in low rpm in 2nd gear. Noise occurs under 2000 rpm, under 20 mph. At higher speeds noise goes away - at regular road speeds, higher rpm, noise not detectable.
Whirring is the best example of the nose, but could be called a very light metal scraping. Any other noise definition might be too dramatic. If you were to very lightly whistle in or out, that could be considered a description of the noise. A shirting at low speeds under different loads should not have a whirring noise like this. All fluids are at their correct levels.
Could be gears that have become misaligned in the transmission.
May, 5, 2012 AT 2:24 AM
I have a 2009 ranger 4.0 5spd, with the same issue.
Most pronounced in the morning then goes away after a few miles.
The sound is exactly like when rust builds up on the rotors, after a night of rain, and the brakes are applied. Heard once shifted into 2nd gear.
May, 5, 2012 AT 3:35 AM
Change the gear oil. It might be contaminated gear oil. If changing the gear oil doesn't cure it, then it's most likely a misalignment between the gears.