For its class, the car steers well enough - better than you expect. And the point is, rather, not in the suspension, but in the frame and torsional strength of the body. With comfort, too, everything is fine if the wheels are of the stock dimension and the body supports are intact. Their destruction is rare, but sometimes there are cars with heavily sagging supports, and it is necessary to look for the reasons for the transmission of noise and vibrations to the body from the suspensions, starting with these elements.
The wheel suspension is quite advanced here. In the front there is a classic double-wishbone suspension, in the back there is a hybrid of double-wishbone and multi-link suspensions - the main two levers are essentially self-sufficient and they are the main load, but the guide vanes have two more small links that provide a change in toe-in.
Everything is done quite monumental, and the resource when moving the car on good roads and in urban mode 100+ thousand is almost guaranteed. The wear parts are almost all replaceable and inexpensive. So, the ball bearings of the front upper and lower levers, all the silent blocks in the front suspension and many in the rear are regularly changed. Unpleasant moments - the use of a sour breakup bolt on the front lower arm and a permanent ball joint at the expensive upper arm of the rear suspension. Even on the mechanical side, it is worth noting the rather weak wheel bearings: sometimes their resource does not even reach 150 thousand, and they really do not like side impacts. You can also scold the weak support of the shock absorber in the front suspension, its pillow is badly broken during operation on bad roads.
The bulk of Mohave owners remember about the suspension only because of pneumatic failures on the rear axle - almost all Russian cars have it. This means that there are many nice little things that can cause a lot of trouble.
Replacement of expensive (200 euros each) level sensors under warranty is the main entertainment for owners of new cars. In regions with a humid climate, problems begin as early as 30 thousand kilometers. Dealers change mainly the sensors themselves, there are two of them, complete with levers. The nuance is that the sensor itself is usually alive and well, the failures are associated with an unsuccessful connector, which eventually gets moisture, and it oxidizes on the sensor. Simply cleaning the connector can bring the sensor back to life, but for normal operation it is advisable to dry, lubricate and seal the connectors.
The sensor rod bracket is flexible, on the one hand, this allows you to adjust the level of the body and xenon without the help of electronics, and on the other hand, the bracket itself slightly skews over time, causing rolls that need to be eliminated.
The resource of the pump and air bellows is quite high; with a normally functioning valve block and flushing, they serve 150 and 200 thousand kilometers. But flushing the cylinder is usually neglected, and the valve block sometimes fails. As a result, the cylinder usually has to be replaced either due to a slow leak, or even an explosion (this also happens). Since such cars are often used for long journeys and for off-road excursions, and it is a pity to refuse pneumatics, many put a "reserve" - emergency pressure relief valves and a manual pumping line, bringing it into the cabin. That allows you to "lift" the machine in the event of a sensor breakdown, a dead pump or a clogged line and to avoid an explosion of the cylinder due to pumping.
Well, it's easy to turn off the pneumatics, since the control unit is located under the driver's seat and there is no need for complex manipulations to remove the connector. Sometimes, in the event of sensor failures, it is enough to reset the block at the right time, when there is no roll of the car, and this will allow you to get to the service.
The steering here is with a conventional power steering rack. The resource is not bad, the leaks of the pressure line are obtained mainly with runs of 200+. The rail itself taps a little already at 50 thousand mileage, but it does not flow, and the knocks are faintly audible.
Here knocks from the steering column are heard much better, and if the "comfortable exit" is turned on, then the chances of increased wear of the spline joint of the steering column are high. And again the trouble with Mohave - there are no non-original or restored rails. Only repairs or an expensive original.
If you think the Slots problem is past Mohave, then no. There is complete order with this. I mean, the shafts of the front wheels are dangling in the CV joint, which generates vibration in the transmission. As usual, the reason is a weak boot and weak metal. As a result, the dealer recommends changing the intermediate shaft and the right CV joint. Budget - spare parts for 450 euros and work. If you save on CV joints, then you can keep within 350, but only the original shaft is available.
The problem manifests itself on cars literally from four to five years old, except, perhaps, in the most southern and driest regions. If the splines are still in order, then a thick grease helps a lot, and if there is already a backlash and the profile of the teeth is broken, then the connection is often assembled on epoxy or strong fixation sealant. Recovery with shank welding and milling is available only to those who find a good machining specialist (there are few of them). But the drilled holes with a bolt driven there - this is already a "collective farm" in its purest form, which is better to avoid.
The front propeller shaft of the cars was even changed according to a revocable campaign due to early wear of the crosspiece, but cars with worn ones come across. Small vibrations during acceleration can be caused not only by the splines, but also by the propeller shaft. The CV joint of the front universal joint is strong enough and rarely breaks. The rear universal joint had no congenital problems. But with 130+ mileage, you can expect destruction of the outboard bearing damper and wear of the rear cross. The slots here are quite successful, they rarely wedge and corrode.
The rear and front gearbox, if you monitor the oil level and change it at least sometimes (better once every 60 thousand), are quite reliable. Leaks due to wear of the oil seals happen, and the breathers can pass water, when overcoming the fords you need to be careful and it is better to immediately check the oil in the bridges for the presence of an emulsion.
The gearboxes on the Mohave are automatic, but different. Diesel engines rely on 6-speed ZF 6HP26, after 2011 they began to install a new 8-speed box of our own design and production with the code A8TR1. Tellingly, it is in many ways "related" to the ZF 8HP line. On cars with V8 engines, the same types of automatic transmissions were installed as on cars with a diesel engine, but you cannot find cars with 4.6 in Russia. You can find a car with a petrol V6 3.8 liter, there is a 5-speed Jatco A5SR2 / JR507A.
The first generation of 6-speed mortars from ZF (6HP26) was remembered for many problems, but the later versions of this automatic transmission are unified with the 6HP28, the second generation ZF six-speed, and therefore are significantly more reliable than the first versions. Let me remind you that the main design features are the use of a kinematic scheme with the Lepeletier series, which allows you to get 6 gears without increasing the dimensions of the mechanism. It is also characterized by low relative angular velocities of the satellites, the use of a circuit with low operating pressure and low oil consumption, the use of a valve body design with a combination of a sensor board, a control unit in the block body (the so-called mechatronic), as well as the use of partial and sliding blocking of gas turbine engines on most operating modes. In normal mode, the gas turbine engine works only in cold, and then in lower gears. The sliding blocking is used in all power modes, in this case the clutch blocking of the gas turbine engine acts as a clutch and transmits torque, allowing to increase the efficiency of hydraulic transmission. And as soon as the opportunity arises, the blocking becomes almost complete. But exactly what is almost - to minimize the transmission of torsional vibrations, the clutch is not completely locked, ensuring minimum slippage at all times. Of the interesting features, one should also note the built-in electronic thermostat of the box and the pressure regulation separately in the hydraulic circuit and separately in the lubrication circuit of the mechanical part.
As a result, ZF managed to create an automatic transmission that has a very high efficiency in all modes and a very high response rate combined with excellent torque transmission capabilities. Even the "average" series ZF 6HP26 has a torque reserve of at least 600 Nm, which makes it easy to withstand powerful gasoline engines and diesel engines up to 250-300 hp. But there is also a downside to the coin.
Continuous use of the torque converter lock-up (GTL) in slip mode causes the same constant oil contamination from the wear products of the lock-up clutch. Too weak hydraulic part of the gas turbine engine with an increase in load due to wear of the clutch or errors in the operation of the blocking hydraulics is prone to breakdowns due to overload. The oil pump of the box and all the solenoids, first of all, the solenoids for regulating the pressure and blocking of the gas turbine engine, wear out strongly, and here they are made according to the Aisin scheme, with channels in the body of the valve body plate. And not only the solenoid itself wears out, but also the body of the valve body, which is much more difficult to replace. The use of lead-free bronze for the bushings in combination with the minimum operating pressure in the sleeve bearings also ensures their high wear and vibration during operation. Well, in addition to this, the design itself has several weak points such as seals of a plastic filter pan, rubber seals-adapters between the valve body and oil channels, seals of the wiring harness - the so-called "glasses" and oil seals.
Among the strengths of the box, in addition to dynamics and efficiency, it should be noted the good quality of self-diagnostics and high limits of adaptability. The valves have a huge working range, and it is more than enough even for the operation of a very worn-out mechanism, adaptation to old oil, its overheating and work with a load on cold oil. Even a half-dead automatic gearbox can drive smoothly, without bumps and jerks. And electronics very well "knows" the quality of work of all units, and with the simplest scanner you can see how worn out the box is.
It is a pity that if the oil is changed "according to the regulations", once every 60 thousand kilometers, or even less often, as is the case with BMW and Audi, and besides, you often press the gas pedal to the floor, then the box does not last long. Leaks, overheating, wear of bushings, valve body, gas turbine linings, gas turbine engine bearing, oil pump, pressure drop and worn-out packages, planetary gear breakdowns begin to appear after 100-120 thousand kilometers. For some unique people - even earlier.
It is good that only later versions of this automatic transmission were installed on Mohave, moreover, they were tuned for very leisurely movement and an increased resource. The regulation provided for an oil change every 60 thousand kilometers or even more often in difficult road conditions, and the automatic transmission cooling system was implemented "in the old fashioned way", with a heat exchanger in a cold radiator tank, which is still an excellent solution for a diesel car.
As a result, up to 100-110 degrees ATF warms up only during long runs on the highway at high speed, and installing an additional radiator can easily solve this problem (plus there are ways to programmatically reduce the operating temperature). So, with runs slightly over 100, the list of gearbox problems is usually limited to the wear of the Direct Clutch B drum, since the diesel torque is very high, and the car is heavy, and even when swinging, this drum is overloaded.
Sometimes you can still encounter wear on the separator plate due to overheating during prolonged driving at high speed or "adventures" on the frame in the mud, and the aging of rubber accumulators-fungi begins to affect.
With runs of 200-250 thousand, the wear of the bushings, the vibrations of the gas turbine engine and the associated wear of the oil pump sleeve and the wear of the clutches of the overdrive drum E begins to be felt. Closer to 300 thousand, a major overhaul or replacement of the assembly almost inevitably follows.
The 8-speed A8TR1 gearbox, which began to be installed from the end of 2011 by Hyundai / Kia, as already mentioned, is in many ways similar to the ZF design, but has been relieved of many shortcomings. In these 8-speed gearboxes, the gas turbine engine works without full blocking only at the start, and the "almost complete" blocking mode is removed due to the presence of a torsional vibration damper in the gas turbine engine. Five solenoids out of eleven are of a classic design, they can be completely replaced without consequences, besides, they are more robust in terms of electrical part, unlike ZF solenoids, which are afraid even of static. And, most importantly, the company promised an 8-year warranty for these boxes, which is a very good help in our difficult times.
It was not completely without drawbacks: the linings of the blocking of the gas turbine engine themselves wear out with frequent starts with the pedal to the floor more than that of the ZF. There are cars with mileage of about 120-150 thousand with clutches worn out to the adhesive layer, a clogged valve body and a dead pump.
The valve body plate material is weaker than that of the later ZFs, so there are some scuff marks. Basically, the channels of the accumulators suffer, they accumulate debris and rub the seats. As a result, the pistons of the accumulators wear out faster and faster, but it is just easy to remove the frank seizures. It is much more difficult to restore the closed channel of the linear pressure control valve.
On the mechanical side, there are almost no surprises, there are boxes with a "trolleybus" howl, this is the first version of the wear of the axles of the satellites. And, what is unpleasant, the timing of the scheduled oil change has been shifted to 80 thousand mileage, and this automatic transmission clearly loves clean oil.
General verdict: the transmission is better than the 6-speed, and with an excellent long warranty. But do not consider it unkillable and, on this basis, deny service. Moreover, the guarantee may be refused, for example, due to twisted mileage or overrun between MOTs.
The five-speed Jatco A5SR2, which are found on individual copies, are structurally related to the earlier generation. There are simple replaceable solenoids, simple blocking algorithms, the automatic transmission control unit outside. As a result, the box quite stably passes at least 150-200 thousand before the first repairs, and the neat owner has twice as much.
There are usually several reasons for the appearance of problems. A weak blocking pad for the gas turbine engine does not like hard starts very much and wears out quickly to the adhesive layer. If you abuse it, you can encounter vibrations and overheating of the gas turbine engine with runs up to 50 thousand, along the way the oil gets dirty, the oil pump bushing wears out.
The second problem is the wear of the clutches and the brake band during runs under 200 thousand or active pedaling. To ensure smooth operation under heavy load, the clutch engagement time is delayed, and they are actively worn out. The first to suffer is the Input Clutch package or the Direct Clutch package.
The wear of the solenoids has not been canceled either - when the oil is contaminated, this happens quickly enough, so the condition of the oil must be checked at every MOT. And faulty solenoids can easily lead to mechanical problems. For calm drivers, the box can easily demonstrate the wonders of the resource: examples of runs up to 500 thousand without repairs are known.
Four-wheel drive is realized using a BorgWarner transfer case with a front axle clutch and a crawler gear. The system is rather "brooding" - unlike Haldex couplings, it works slowly, with a delay. But it is quite reliable and does not often require changing the oil. You need to monitor the operation of the motor for switching modes, it usually suffers from moisture in the connector and corrosion, and as a result, the motor itself rotts out from the inside, and this is expensive. There are enough clutches and a chain for runs over 250 thousand, if you do not abuse the off-road conditions and sometimes change the oil in the unit.
By the way, there is one interesting off-road tuning option on Mohave. Since in terms of installation dimensions the box is compatible with BW with a differential inside, enthusiasts have already been able to install instead of the transfer case with an “on demand” clutch, its analogue with permanent all-wheel drive from SsangYong, replacing only the rear propeller shaft. Let me remind you that the original all-wheel drive system has a weak point in the form of ABS sensors and weak wiring, in case of errors on them, the car turns into a rear-wheel drive one, so this modification is quite justified for jeepers.
The spacious engine compartment and the excess area of the radiators, and at the same time the simple and resourceful pipes of the cooling system and the intake allow you to have a minimum number of problems with the engines and their maintenance. Even the supports are long-lasting. True, all motors do not tolerate the slightest decrease in the level of antifreeze in the system, and its leaks in cars with a collective farm installed preheater or, for example, as a result of damage to the radiator on the road, happen.
It was not possible to meet V8 from KIA in Russia, but V6 3.8 G6DA are on sale. With runs of more than 200 thousand, it no longer pleases with wear of the piston group and oil consumption, knocking of phase regulators, breakdowns of the intake manifold and leaks. On a heavy SUV, it gives neither dynamics nor efficiency. It is doubtful that it will be cheaper in operation than the diesel 3.0. And among the contract units there is a clear deficit, a clear sign of an unsuccessful engine.
The bulk of Mohave is powered by 3.0 CRDi diesel engines of the D6EA and D6EB series. With all the similarity of characteristics in small things, they are very different: they have different cylinder heads, glow plugs, fuel equipment, injectors, EGR and many other elements. The newer option, which is logical, corresponds to more recent environmental standards.
Overall, the 3-liter diesel is very successful. Many sources confidently call it a strengthened version of the Isuzu DMAX 6DE1, but in reality this assumption turns out to be fiction. The engines have different design of the cylinder block, completely different cylinder head, different timing drive, and the fuel equipment differs dramatically. Unless the volume and configuration are the same, but there is something in common in the design of the front wall of the block.
There is an all-cast iron block without problem sleeves, a timing chain with a resource of about 250-300 thousand kilometers, Bosch fuel equipment and a BorgWarner BV50 turbine.
The list of problems is rather short. Glow plug power supply failures occur regularly, and oil appetite is usually associated either with a malfunction of the crankcase ventilation system valve, or with a turbine resource. It is better to change the valve every 30-40 thousand mileage, and the oil on the pipe behind the turbine will indicate problems with it.
The turbine does not die suddenly, but the oil starts to drive into the intake a little early enough - to 130-150 thousand. Fortunately, it is installed conveniently, you can check for backlashes and for oiling.
On D6EB engines, the turbine is slightly different, but with the same cartridge, but its resource was increased to a confident 200. The price of a cartridge is ridiculous 120 euros, so replacement is not ruinous. The electric drive of the VGT variable geometry actuator here reliably serves up to at least 150 thousand kilometers. Often the death of a turbine is associated precisely with its failure and regular overdrive.
Another reason for overdue is not very successful absolute pressure sensors. They become soiled with carbon deposits and underestimate the readings. Fortunately, it is easy to remove and clean them with a carbcliner, they stand directly on the intake manifold from above. Unless it is better not to use highly aggressive liquids. The reason for the intensive formation of carbon deposits is the operation of the EGR valve. There is no particulate filter here, so the intake gets very dirty. The valve itself almost does not break, but if you want to turn it off, you will have to sew a control unit, it has a multi-level check of the system's performance. The reward will be about 300 forces and 650 Nm of torque on the tuners' favorite firmware "for Euro-1". The engine after it is just a jet, but the automatic transmission can hardly digest such a thrust.
The diesel engine also has a mass air flow sensor (MAF), it is often also dirty, but this is already on the conscience of a rare replacement of the filter and crankcase ventilation valve - as it ages, the thrust drops dramatically and smoke appears at low load.
Timing chain life is high, tensioners are inexpensive, and everything is simple. The only pity is that with runs of 250-300, in addition to noise, the chain can slip a little. Usually without serious consequences, only with a strong loss of thrust and smoke, but occasionally valve breakage also occurs.
Comments
Post a Comment