199000641 - INTRODUCTION C514 MANUAL GEARBOX AND DIFFERENTIAL -5 SPEED
CONSTRUCTION SPECIFICATIONS
The C514 gearbox fitted on the vehicle is a gearbox that has been developed to improve manoeuvrability and reliability and is fitted in conjunction with the 1.2 8v and 1.4 8v 5 speed versions.This version is the most powerful gearbox in terms of torque transmitted (15 kgm). The use of noble materials for the gears, the use of a powerful differential with oversize conical gears and the connection between the casing and ring nut using bolts ensures maximum reliability.Its main features are:- excellent manoeuvrability of the gear control- quiet operation- reduced weight.The configuration is transverse with 2 shafts and a differential.
MAIN SHAFT
The main shaft consists of:- 1st, 2nd speed and Reverse gears directly on the shaft;- 3rd, 4th and 5th speed gears fitted on the shaft.The main shaft is supported by a front roller bearing and a rear ball bearing.
LAYSHAFT
The lay shaft consists of:- 1st, 2nd, 3rd, 4th and 5th speed gears fitted on the shaft.The layshaft is mounted on:- a front roller bearing- a rear ball bearing.
GEARS
The gears are the following type:- helical toothed for the forward gears- straight toothed for Reverse gear.The teeth for all the gears are HCR (High Contact Ratio).The 2nd and 5th speed and final drive gears are superfinished after the thermal treatment to guarantee absolute precision for the teeth and quiet operation.The kinematic components inside the gearbox casing are lubricated dynamically, by means of the oil flowing along channels and through ports in the casings, the 3rd/4th speed rod and the main shaft; this allows:- improved torque transmission and greater efficiency against the effects of wear- manoeuvrability even at low temperatures thanks to the use of synthetic multigrade oil.
SYNCHRONIZERS
The synchromesh on all the forward gears and reverse is the brass, baulk ring type (Borg-Warner) and is on the layshaft for 1st and 2nd speeds, on the main shaft for 3rd, 4th and 5th speeds and on the idler shaft for reverse gear.This solution reduces gearbox noise when stopped in neutral from the moment that 3 of the 5 pairs of gears are not driven.The engagement and synchronization loads are also reduced as a result of the corresponding reduction in the inert rotating masses downstream of the crankshaft.The synchronizer on 1st and 2nd speeds, the most used gears subject to the most stress, is the double cone type requiring far less engagement force compared with a single cone type traditional sychronizer of the same size (- 40%).A new pre-synchronizer system comprising thrust bearings is used on all the gears to improve sliding and engagement: in 1st and 2nd speeds the sliding gears are supported by roller chambers. The geometry of the reverse gear teeth has been improved to guarantee excellent manoeuvrability and rapid and precise engagement.
DIFFERENTIAL
The differential uni is located in the rear part of the gearbox casing.It comprises:- a crown wheel reduction- a differential housing in a single piece which incorporates the planet and satellite gears.The differential is supported by two conical roller bearings.The planet gears have a splined internal profile in which the two joints connected to the two driveshafts that transmit the drive to the wheels mesh.The speedometer idler drive gear is fitted on the outside of the differential housing.
