ZF 9HP transmission

These ordinates are positioned on the abscissa in strict accordance with the proportions of the sun gears' teeth numbers relative to those of their rings.

▶️ Interactive Nomogram This interactive nomogram is a real geometric calculator exactly representing the rotational speeds of the transmission's 3x4 = 12 internal shafts for each of its 9 ratios (+ reverse), grouped according to their 5 permanent coupling on 4 joint ordinates and 3 independent ordinates.

These ordinates are positioned on the abscissa in strict accordance with the proportions of the sun gears' teeth numbers relative to those of their rings.

Consequently, the output ratios on the 6th ordinate (carrier of the fourth planetary gearset) follows closely those of the actual transmission.

A: Dog brake (blocks S3 and S4) C: Brake (blocks S1) D: Brake (blocks R2) B: Clutch (couples S1 with input shaft) E: Clutch (couples C3 (carrier 3) and R4 with input shaft) F: Dog clutch (couples R1 and S2 with input shaft) The transmission has been problematic, as customers of Jeep, Chrysler, and Acura models equipped with the transmission have experienced problems in their vehicles regarding slow shifting and noisy operation.