The market of cars with two clutches and robotic change speed gearboxes grows every year. The word “Powershift” to already familiarly many motorists, especially – to owners of new models Ford and Volvo with run. So it for such box? It is how reliable? Let’s try to understand.
It is a little history
The idea of creation of such transmission belongs to the Porsche company which in the 80th years of last century conducted similar developments. The German engineers correctly considered that pilots of racing cars spend precious tenth fractions of a second for switching drive on the manual transmission, and at these moments the car loses power. Automatic machines of that time did not differ to the necessary auto racing in speed.
Generally, the question of creation of “fast” gear box has ripened in itself. With implementation of the project it has been decided not to delay, and Porsche has quickly given green light to its development. Knowing the German sense of duty, the fact that in 1982 the predecessor of Porsche 956 equipped with robotic box with two clutches has won the race Le Mans will not be surprising. But such change speed gearboxes have not gone to series as differed in weak reliability of which the electronic industry which did not have opportunity for that time to exhaust really effective electronic payments was guilty.
Insufficient development of electronics has forced to postpone implementation of this project for that time. Return to it has happened in couple of decades. And began to develop subject at once several companies. So, for example, the German concern VAG has entrusted development of the DSG to the American firm Borgwarner, and here Porsche has addressed ZF. Other car makers invested means in development of change speed gearbox from Getrag.
Much the German Ford has invested in this invention, and here in 2008 the presentation of wet preselektiv of Powershift 6DCT450 has taken place. And literally in a couple of years, the participant of the project the LuK company has submitted more compact dry version under index 6DCT250.
- In practice the box of dry type also uses oil. For example, in 6DCT250 it 1.7 liters are filled in. For comparison in wet 6DCT450 its 7 liters.
It is worth deciphering these abbreviations that the further text was more clear.
6 — the number of drives;
D — double (double);
With — clutch (clutch);
T — gear box (transmission);
250 — the maximum torque.
Versions of boxes and their application
Now in series there are two Powershift robots differing as basket who are issued in various versions.
These are boxes:
• WD (Wet Dual Clutch – clutch of wet type, box with hydraulic control);
• DD (Dry Dual Clutch – clutch of dry type, box with electronic hydraulic control).
The Getrag producer at the moment takes the second place in the world on release of robotic preselective gear boxes. He expects to become leader in the field within ten years. The list, the robotic change speed gearboxes which are exhausted by it:
• Dry 6DCT250 (PS250) are established on 1.5-liter Renault and on Ford with volume up to 2.0 liters;
• Wet 6DCT450. Chrysler, the European Volvos, Ford, Renault and Land Rover (DPS6/MPS6) is used on American. The box has the extended design because of which cannot be established on compact cars;
• Box 6DCT470 (WD type, wet clutch). Is established on the Mitsubishi Outlander, Lancer, Galant cars and others;
• Dry C635DDCT. Was established on minicars from Fiat, Dodge and Alfa Romeo. Has to maintain 350 Nanometers of torque;
• 7DCI600. Development for not the really popular “loaded” models from BMW with longitudinal arrangement of the engine;
• 7DCL750. The same, as the previous box, but for Ferrari.
Typical problems of Powershift
Current situation – the correct use of transmission which is recommended by the producer is paradoxical, conflicts with the principle of operation of this unit. For example, in practice for life extension and bigger comfort in plugs it is better to move in “sport mode”. Of course, quicker the car will not go, but will move on drive of S1, and the constant pulling appearing as a result of the choice between the first and second drives will disappear.
Also it is worth approaching deliberately and the oil choice. Though preselective boxes from Getrag are also installed on models of different car makers, it is necessary to fill in concrete oil from manual. It is connected with settings of change speed gearbox under each concrete model. For example, Ford recommends semi-synthetic BO-DC (the German Ravenol has analog). If partial replacement of liquid is carried out, then also the fine filter changes. At full replacement in addition it is necessary to change also cartridge.
It is possible to feel all charm of robotic change speed gearbox on operational scope of the route. Drives change literally behind the couple tenth fraction of a second that provokes “to start” fans to do it in the conditions of the city – frequent intensive dispersals and the same frequent hard brakings. All this pours out in under cooling of the robot that very harmful affects its state (especially is afraid of it dry 6DCT250).
The majority of the Russian Fords Focus of the third generation with the atmospheric engine are equipped with box 6DCT250. The car maker declares its profitability, instant gear shift and drop of toxicity of exhaust. Sounds very beautifully, but in practice motorists have faced number of the serious problems connected with this box.
Though “diseases” of change speed gearbox has a little, but all of them are shown approximately equally – breakthroughs, pushes and vibration during gear shift, emergency the mode of box and refusal of the car to move.
The most frequent failure – the current sealing glands on primary to shaft through which the automatic transmission fluid gets on both clutches and it begins to slip. On the odometer this failure does not depend on figures in any way, there were cases of leak of sealing glands both on 5 thousand, and on 60 thousand km of run.
Quite often can wedge forks of inclusion of clutches, and both. The problem is solved by only full replacement of sets with forks and sealing glands. And it is necessary to install sealing glands of new sample.
Problem is also the oxidized hydroblock payment (mechatronics). And, even approximately it is impossible to foresee this moment after which the car will completely be immobilized. Though the mekhatronik folding, and in practice maintainable, the dealer offers its replacement assembled. The same concerns also solenoid coils, it is possible to make their separate replacement only in the service specializing in repair of robotic boxes.
Causes problems and the TCM module with executive electric motors which switches drives and squeezes out clutch. It is not always expedient to change knot assembled. Even the failed electric motors can be restored new winding and replacement of rotor. But can burn out printing paths on electronic payments, and here only replacement of payment will already help (everyone approximately on 35 thousand rubles).
The problem at which the car does not see the chosen box mode is also connected with the TSM module. There is it usually during heat as engineers Ford have not registered properly in ON correct work of the cooling systems in summer heat.
Can fail also the steering manual gearbox block which is not under repair but only changes assembled on modifed. The fact that these troubles could appear all at the same time is sad, and then repair punched huge gap in the family budget.
Let’s give approximate calculation of similar repair at official dealers of Ford in Moscow (the prices in rubles):
• Two clutches (original) – about 87 thousand. rub;
• Big and small forks: 67 thousand. rub;
• The TSM module – 49 thousand. rub;
• Sealing glands of main drive shaft 1.3 thousand. rub;
• Work – 18 thousand. rub.
Total – 222 with kopeks thousands of rubles that budgetary Ford Focus unambiguously shocks the owner. It turns out that post warranty repair of robotic change speed gearbox at the price approaches the residual cost of the car.
Of course, it is not normal. And Ford is aware of problems of the preselective boxes, and has even carried out their modernization. At the address on guarantee of “official” without problems solve problem and suggest to pay in addition for expanded guarantee that it is very much recommended to owners of Focuses which robotic change speed gearbox is still serviceable.
In 2014 clutch has been modernized, sealing glands of shaft of change speed gearbox and differentials are changed, the software is corrected. And since then the car maker assures that the number of refusals of boxes of Powershift tends to zero. Choosing the third Focus in the secondary market, extremely it is not recommended to buy options with such change speed gearbox, and here new postrestyling cars can be considered to purchase. It is very important that the car was for guarantee. Besides, for certain payment, the official dealer can provide the guarantee expanded on time. The last I strongly recommend to use option.
Repair of boxes of Powershift
Services which specialize in repair of robotic change speed gearboxes help out car owners. But, most of them prefers to deal with DSG, than with boxes Ford. It is connected first of all with deficiency of details – there is no mass production separately spare parts for Powershift.
In the Russian Federation there is separate market on sale of these spare parts, but, the entrance on it to ordinary motorists is closed. All above-mentioned details are taken, as a rule, from the boxes with small run which are written off on guarantee. They have practically no wear and possess decent residual resource.
There are on sale also new preselektiv which are recognized car maker as defective. For example, in transit the box has sustained minor damage of dome, and will not install it on the conveyor any more. These spare parts are sold only among cross-sectional services which allow car owners to save the decent sums of money, than they would address for repair “official”.