Toyota 4Runner Operation and Maintenance Blog

Toyota 4Runner Operation and Maintenance


4WD control

First of all, it is necessary to pay attention to the modes of the transfer case (hereinafter RK), incorrect use of which leads to serious damage to the transmission. If the implementation scheme of all-wheel drive on your car Part-Time (RK is not equipped with an axle differential, and the front-drive is rigidly connected or disconnected), in no case should not use the 4WD mode on the pavement that provides good grip (dry or wet asphalt or another road surface). This is due to the fact that such RK rigidly connects the drives of front and rear Cardan shafts (and thus the main pairs of axles). Angular speeds of these shafts are almost always different, except when the car moves strictly straight. In this case, the smaller the turning radius, the greater the difference in angular speeds. Where does this difference go? This difference should go to a slight slippage of wheels against the surface of movement, which happens in mud, snow, sand, grass, etc. But with a good grip of the wheels to the road, easy slippage is impossible, and in a turn, the angular speeds of the main pairs of bridges should be different. RK does not give them such an opportunity. As a result, there is a very strong tension in the entire transmission chain, and the wheels still go into periodic breakdowns. This leads to jerks when driving in a curve and to the rapid failure of the transmission. In this case, usually jammed RK (an also possible variant of a torn chain or gears), Cardan crosses also need to be replaced, the increased play of the main pairs, suffer from differentials, and SHRUSes.

If your car all-wheel drive is implemented as Full Time or Multy Mod 4WD (in the case of our platform such Full-Time RK is always equipped with a center differential with hard locking), then you can move to 4WD whenever you want (multi mod 4WD), or only always (Full Time). The center differential allows the RK to transmit torque to the front and rear Cardan shafts with different angular speeds. It should be noted that by blocking the center differential, we get a similar situation with Part-Time: angular speeds of Cardan shafts become the same again. Accordingly, in this mode, it is necessary to take into account the type of coating on which the car is moving. It should also be noted that the differential lock mechanism is a very thin and fragile thing. Therefore, the driving style, which can be afforded at Part-Time should not be used in the case of a locked center differential.

Toyota 4Runner Operation and Maintenance Blog

The cars of this family are rather unpretentious in maintenance. The main thing is not to save on fuel and lubricants and to perform maintenance on time. Saving here will come out sideways. Information about the necessary maintenance, with intervals, is given in the manual for each car. In normal urban use, maintenance should be carried out at least:

  • Engine oil (synthetics) – every 10 t. km.
  • MKPP and RK oil – every 40 t. km.
  • Automatic transmission oil – every 30t. km.
  • Oil in bridge gearboxes – every 40t. km.
  • Translated with (free version)

Syringing the corresponding nodes – every 10 t. km. (Usually, this is done together with engine oil change). If you have IFS, do not forget to syringe the ball bearings, even if they do not have oil filters. The hole for the oil bottle is simply plugged by a bolt, which must be unscrewed and the oil bottle installed. After syringing the bolt will return to its place. Do not forget to replace the antifreeze, brake fluid (for braking and clutch system), fluid for the HSD system.

If the machine is operated in very difficult conditions and often overcomes water obstacles, maintenance should be carried out much more frequently – up to and including service after each raid. This applies primarily to syringing and oil changes in the units (especially if they are not additionally prepared to overcome deep fords).

Particular attention should be paid to the cooling system, or rather to the radiator and the silicone clutch of the fan. After the down, they should be blown and washed (especially if the car is equipped with air conditioning – down is clogged between two radiators and does not allow them to cool normally). If the silicone clutch radiator gets clogged with dirt, the clutch will overheat and soon fail. When overcoming particularly dirty sections of the track, the cleaning procedure for the heatsink and the clutch will not hurt either.

Toyota 4Runner Operation and Maintenance BlogThe cars of the family were standardly equipped with wheels: for the 1st and 2nd generations – 215R15 (full profile, series = 80%), 265/70R15; for the 3rd generation was added the size 265/70R16, for the fourth – 265/65/R17. In this case, the maximum size of the wheels that can be installed without an elevator on the 1st and 2nd generation – 265/75R15 (ie 31X10.5), for the third generation – 265/75/16 (actually you can put 32X11.5).

The natural desire to install large diameter and width of mud wheels, to improve the cross-country ability of the car, occurs quite often. However, this will have to resort to a car elevator, the technology of which is described in section modification. The most optimal size of mud wheels for 4Runner and other cars in the family is 33X12.5. With the same success, you can use wheels 35X12.5. To install 38 and 44-inch wheels, more serious modifications are required. So why choose the 33X12.5? There are several reasons for this. First, for a relatively lightweight 4Ranner (1700, 1850, 2000 kg. for the first three generations, respectively.), the width and height of such tires are quite enough for confident movement in various difficult terrain. Specific pressure on the ground at such a weight of the car and the width of the tires is quite small and allows you to move on deep mud and swampy terrain. For heavier full-size SUVs weighing under 3000 kg, such size of tires (33X12.5) is not enough to significantly reduce the ground pressure. Secondly, this size of mud tires is one of the safest for the transmission (with an increase in diameter and width of the wheel, as well as its mass, greatly increases the load on the hubs, axles, HP, suspension, etc.). When installing BFG MT 33X12.5 on a good forged alloy wheel, you get the total mass of the wheel, not exceeding the standard. Tire 35X12.5 weighs already heavier. Third, with the size of wheels, the 33X12.5 car does not lose much in acceleration dynamics and is quite tolerable to drive at speeds up to 150 km / h. At the same time, the economy of the car does not deteriorate as much as with 35 wheels (if it is gasoline, and does not deteriorate at all – if it is 1KZ-T diesel). In other words – the use of 33X12.5 is the most universal variant for city/off-road operation. Size 35X12.5 is also suitable for such an operation, but in the city is not so good. On the other hand, the off-road gives an additional 2.5 cm clearance.

Toyota 4Runner Operation and Maintenance BlogAs for tires for winter operation, I do not advise to drive on asphalt in winter on rubber with BFG MT, Cooper STT, SSR, and other mud treads, even if such rubber is wrong. Of course, a wrong tread is better than a naked tread, but with this type of tread on slippery asphalt with slurry under which the melted ice, even spikes will not be very useful (especially at speeds above 30km/h). The complete (or almost complete) absence of lamellae on such types of tread makes it similar to bald rubber. The absence of a directional pattern leads to a “cushion” of porridge, which impairs both braking and handling. I am not talking about side demolition anymore. And if we add to all this the fact that the tires with a mud tread usually choose wide (from 12.5″), then due to low ground pressure, all of the above disadvantages are amplified many times. Again, all this applies to riding in winter in urban conditions – ie, on the asphalt. If you drive in the field on deep loose snow, under which the mud, or on another off-road – then the mud tread is the same, and preferably wrong. As for spikes in general – I believe that studded winter tires are better than non-spiked. There are situations in which spikes can behave a little worse on the Dry or IOC road – for example when entering a 90-degree turn at a speed of 60 km/h or more. This “slightly” may be enough to lose control. However, winter tires are not used for driving on roads, but on the contrary – for safe driving. In all other situations, studded rubber is much better than the non- studded rubber.

The key value in choosing winter tires is the SIZE correlated with the car weight. The rubber of the wrong size (too wide or too narrow) will lead to poor handling regardless of whether it has spikes or not, and what it’s a pattern. Naturally, different sizes are needed for different operating conditions. The right combination of size, tread, and spikes will lead to an optimal result. For off-road applications, a mud-cleaning self-cleaning tread is better (the softer the better), preferably with spikes in case of full ice. Usually, the same rubber is used as in summer in the mud. For a city, it is better to use winter directed, not wide, spiked rubber. Driving around the city for one winter on a 2nd generation 4Runner with rubber 265/75/15 (31X10.5), I was dissatisfied with the behavior of the car, which was constantly dragged on the slippery road, even with the front-drive turned on. It seemed to me that this rubber was too wide for such a car. Then I decided to try a width of 245 or 235. Given that the 245 is a fairly rare size, I bought one of the most common tires, the Nokia Hakka. 235/75/15. The result was excellent. The next winter, the “yaw” disappeared and the car started to drive perfectly on any slippery porridge even with 2WD. The only negative aspect is the aesthetic one. Rubber with size 235/75/15 looks funny on the 4 Runner, especially on the elevator. I believe that winter rubber with size 265/75/15 (31X10.5) is just right for the 3rd generation of the model, which is heavier than the second by about 200 kg.


1 thought on “Toyota 4Runner Operation and Maintenance”

  1. Well first let me say I traded in my 2015 Mustang GT which I bought new for this 2020 Toyota Nightshade 4wd. I wanted to but a Jeep Wrangler. My fiance’ is clearly happy I didn’t but I needed time to let it all sink in. I cannot say enough what a great chance this was. The ride of this 4Runner is MUCH better than people give it credit for. I’ve had an Explorer before so I know. People write it doesn’t have all the luxuries of comparable SUVs like blind-spot alert, auto tailgate, and auto start. First, let me tell you, I rarely even used my blind spot alert for my Mustang, and opening the tailgate myself is not a deal-breaker. As far as the auto start, I just downloaded Toyota’s app so I can now auto-start the 4Runner from my phone and lock/unlock the doors with a click of a button!!. The quality inside is definitely there, the 15 speaker JBL sound system sounds better than my old Mustang Shaker system. The slide-out tray in the back for loading and unloading items is definitely a nice addition. Now I know why people buy 4Runners. They are durable, dependable and they ALWAYS hold their value. I’ve had my 4Runner now for a month and I know I made the best decision ever!

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