Table 3.

Noise source and order information of the test tractor.

Source	Component	Order
Engine	Main order	2
	Fan	11.6
Transmission	Main shift	40
	Transfer case	48.7
Axle	Front differential	13.91
	Front final reduction	4.35
	Rear differential	13.91
	Rear final reduction	3.62
Hydraulic pump	Input gear	43
Tire	Front No. of lugs: 19	1.38
	Rear No. of lugs: 21	1.16