Mercedes M-Class W163
since 1997 of release
Repair and car operation
+ Mercedes-Benz Cars of a class M (W163)
+ Governing bodies and receptions of safe operation
+ Current leaving and service
+ Systems of cooling, heating and air conditioner
+ the Power supply system and production of the fulfilled gases
+ Systems of electric equipment of the engine
- Manual box of gear shifting
Adjustment of a drive of switching of RKPP 717.461
Removal and installation of the lever of switching of RKPP 717.461
Features of a design of a shtokovo-trosovy drive of switching of RKPP 716.644
Removal and installation of the lever of switching of RKPP 716.644
Removal and RKPP installation
+ Avtomaticheckaya transmission
+ Transmission line
+ Brake and auxiliary systems
+ Suspension bracket and steering
+ Onboard electric equipment
Manual box of gear shifting
At the expense of the energy allocated at combustion in cylinders of an air and fuel mix a cranked shaft of the engine the torque, thus frequency of its rotation develops lies within rather narrow range. The majority of modern engines of an OHV design develop the maximum torque at turns about 2500 in a minute. At increase in frequency of rotation of the engine the size of its torque decreases to 4500 rpm so that the further increase in capacity is not obviously possible any more. Engines with the top arrangement of a camshaft (OHC) are capable to develop considerably a bigger torque, however in much narrower range of frequencies of rotation.
Use in the transmission line of such component as the transmission allows to regulate relationship between turns of the engine and speed of rotation of driving wheels of the car, providing rather high efficiency of return of the power unit practically in any service conditions of the car.
Smoothness of transfer of a torque from a cranked shaft to primary shaft of a manual box of gear shifting (RKPP) is provided by coupling assembly, the design and which principle of action are disassembled in Head the Transmission line of the real Management. Consecutive gear shifting in the course of change of speed of movement of the car is provided at the expense of use in a transmission of a multistage reducer. The transfer relations of each of five/six steps of RKPP provide maximum efficiency of transfer of capacity developed by the engine to driving wheels of a vehicle at various speeds of movement.
On two of the all-wheel drive Mercedes-Benz models of the M-class considered in the real Management besides automatic transmissions (see. Head Avtomaticheckaya transmission) manual transmissions (RKPP) of one of two types can be used: 717.461 (ML 230) and 716.644 (ML 270 of CDI). Both boxes have the standard design used on the majority of Mercedes cars with a classical back drive (series 717.4 and 716.6).
Transformed RKPP developed by the engine in reducer a torque acts in film since the back end of the main shaft and is transferred to an entrance shaft of the transfer case which is carrying out its further distribution between forward and back by leading bridges of the car. Detailed information on a design and a principle of functioning of a transfer case is provided in Head the Transmission line of the real Management.
In both transmissions synchronization of all of five (717.4) / six (716.6) steps of switching of all forward transfers is provided.
It is meaningful to give a little attention to features of functioning of more modern six-step RKPP.
Boxes of a series 716.6 belong to the class completely synchronized 2-вальных of 6-step check points with one reverse gear, received wide application both on rear-wheel, and on the all-wheel drive cars equipped both with petrol, and diesel engines.
General view of RKPP 716.6
RKPP 7.6.6 design
Competent use of the 6th transfer allows to achieve essential economy of fuel consumption at the expense of decrease in working turns of the engine. In view of design features 6-step transmissions have bigger weight, than 5-step.
The box perceives a torque from the engine by means of usual coupling of the dry type equipped with the automatic jack of wear. The case of RKPP has a tight design and refuels transmission oil not needing replacement.
Accuracy and ease of switchings having a short course is reached by the following features of a design:
Assemblies with shaft are located with Reduktornye between two bearing planes. The third bearing plane used in earlier 5-step boxes in this design is eliminated.
The two-section separate case is made of an easy alloy and pressurized by means of a special liquid compound.
The entrance shaft (1) is fixed in a flywheel by means of the directing bearing, and a transmission case - by means of the ball bearing with a profound flute. Main (2) and entrance (1) shaft are jointed among themselves in the general plane of a case of transmission and fixed by means of ball bearings with a profound flute (see in the same place).
The intermediate shaft (3) has the facilitated hollow design and is fixed in the roller coupling and the ball bearing with a profound flute.
In view of the minimum production admissions of semi-cases and gear wheels, and also at the expense of use of roller couplings, need for adjustment axial люфтов shaft disappears.
Movings of the lever of gear shifting are transferred through drafts to a box. Removal of RKPP can be carried out separately from the engine, need for removal arises at coupling service, and also in case of need carrying out regenerative repairs/replacements actually RKPP.
In view of complexity of a design of RKPP, absence on free sale of necessary replaceable internal components and need of use of the special equipment, originators of the real Management do not recommend to owners of cars to carry out major maintenance of a transmission by own forces. Box repair in the conditions of a workshop of car-care center is rather expensive operation, in a type of that, it is necessary to consider alternative options of replacement of the failed block new or restored. Any useful information on repair and replacement of transmission can be received at Mercedes-Benz company car repair shops. Regardless of the chosen way of elimination of problems (repair or replacement), independent dismantle of a box from the car will allow to reduce material inputs essentially.
In this Part of Head descriptions of processes of performance such, lying within qualification of the average amateur mechanic of procedures, as the general adjustment of a drive of gear shifting and removal/installation of assembly of RKPP are offered attention of the reader. Councils on switching management ми are stated to RKPP in Head Governing bodies and receptions of safe operation.
Information on automatic transmissions (AT) is presented in Head Avtomaticheckaya transmission.