#Zf 8 speed transmission manual

ZF 9-Speed Transmission Problems Continue on Jeeps.ZF relies on computers to anticipate the precise moment both halves of each dog clutch are spinning the exact same speed, and engagement happens without the slightest crunch, as proven by our short sample in an Evoque test mule.

#Zf 8 speed transmission manual

Synchromesh helps dog clutches within a manual transmission from grinding away and easing gear changes. The tricky part of the canine clutch is how, or rather when, to engage them. The beauty of a dog clutch is there’s little-to-no parasitic loss when they aren’t engaged, whereas a conventional friction clutch zaps some efficiency, and they’re relatively compact. This is why ZF implemented two dog clutches in the 9HP. More ratios require more shifting elements and these add weight, complexity, and drag to the transmission. Simply adding ratios to a transmission might not make it a tool for greater efficiency, however. This arrangement trims some width from the four-gearset tranny. In this nested pair, the annulus, or ring gear, of the smaller planetary doubles as the sun gear of the larger set. Of those four planetary gearsets, two of them are nested. With four planetary gear sets and six shifting elements (brakes and clutches) that’s a very dense 14.4 inches. It’s no surprise, then, that the 9HP is 14.4 inches wide. According to ZF, which announced it will initially supply the 9HP to the Jeep Cherokee and the Land Rover Range Rover Evoque with more customers to come, the maximum width for such a transmission is about 14.6 inches. The gearbox, along with the engine, has to fit between the shock towers. The trouble with engineering a transmission for a transverse application is packaging. ZF 9-Speed Automatic FWD Transverse Applications.