BUSINESS SEGMENT INFORMATION - Summary of Segment Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Total sales	$ 922	$ 920	$ 806	$ 699	$ 728	$ 841	$ 821	$ 809	$ 3,347	$ 3,199	$ 3,505
Commercial Truck & Industrial
Segment Reporting Information [Line Items]
Total sales									2,533	2,369	2,649
Aftermarket & Trailer
Segment Reporting Information [Line Items]
Total sales									814	830	856
Operating Segments
Segment Reporting Information [Line Items]
Total sales									3,347	3,199	3,505
Operating Segments | Commercial Truck & Industrial
Segment Reporting Information [Line Items]
Total sales									2,615	2,445	2,739
Operating Segments | Aftermarket & Trailer
Segment Reporting Information [Line Items]
Total sales									853	860	884
Eliminations
Segment Reporting Information [Line Items]
Total sales									(121)	(106)	(118)
Eliminations | Commercial Truck & Industrial
Segment Reporting Information [Line Items]
Total sales									82	76	90
Eliminations | Aftermarket & Trailer
Segment Reporting Information [Line Items]
Total sales									$ 39	$ 30	$ 28