Toyota Land Cruiser Gearbox & Transmission Problems

Torque converters have been known to seize and, if that’s the case, it could stall the engine because there’s no slip to allow the engine to idle while the car is stationary. You need to have this checked by a transmission specialist who may have seen this very thing before. Either way, the vehicle won’t be going anywhere under its own power.

Even if the gearbox itself had frozen solid, the torque converter should still allow enough slip to let the engine idle. So that’s definitely where to start the investigation.

It could any number of things and the dealer should be able to identify and rectify the cause for you. It could be as simple as a faulty solenoid in the transmission, a problem with the car’s computer, or a dodgy electrical connection.

The gearbox is sealed in production and it's not meant to be serviced for "life", but what "life" means is anybody's guess. Oil is the lifeblood of an auto transmission and Andrew of AW Automatics is of the old school, which advocates changing the oil every 20,000 km, particularly if the car is being used for towing. On that basis you would be well advised to have it changed.

YOU'RE right, it is a messy situation, so we asked Toyota for an explanation, which was: The Land Cruiser diesel automatic transmission gear change points were optimally chosen to ensure the best balance between performance, driveability and economy. In order to maintain the original design for most owners and also provide an option for earlier sixth-gear engagement, an ECU reprogram was developed to change the sixth gear shift point when "S'' mode (S-6) is selected. Once "S-6'' appears in the display, the transmission will automatically select 1 to 6 according to the vehicle speed and driving conditions similar to "D'' range except that sixth gear engages earlier.

Toyota Australia spokesman, Steve Coughlan replies: “From our records, Brighton Toyota has reported a very light vibration at speed consistent with when the torque convertor lock-up clutch engages. To fully understand the issue we will arrange for one of our Technical Field Managers to contact Mr Jeffrey and assess the vehicle. A member of the team will contact him to set up a meeting”.

I’m amazed that you managed to find such a convoluted reset procedure, even if it only provides a temporary fix. You may well be right that this behaviour is linked to heat build-up, especially if it happens after several hours of driving.

It’s interesting that you mentioned the engine sometimes goes into limp home mode, because the transmission’s behaviour sounds a lot like it’s going into limp home mode, too. Limiting the gears the vehicle will select is a classic symptom of limp-home mode, in fact.

The real question then becomes, what’s causing it to do so. Limp home mode can be initiated any time the vehicle thinks that continuing to drive at full power or speed will do further mechanical harm. As such, there’s a huge range of things that will cause limp home mode to engage, including a leak somewhere in the turbocharger’s plumbing, low coolant level, low oil pressure, low fuel pressure, a faulty sensor and many more.

So the first job is to scan the vehicle and see what fault codes are thrown up by the computer. From there, you can home in on the actual problem and fix it. But without those codes, you’re kind of flying blind.

The cruise control issue could be a fault with the body computer whose job it is to talk to the computer that controls the car’s engine and transmission and turn the driver’s instructions into actions. If there was a problem with the physical actuation of the cruise-control, it would potentially not work at all. But a problem that resets when you turn the ignition off and on again is always cause to suspect a computer glitch.

The transmission issue is one that has been ongoing sine the 200 Series was launched. Top gear (sixth) is so tall for fuel-economy purposes that the vehicle in its original form would not select that gear below about 110km/h. That’s fine for the USA and Middle East where cruising speeds are higher, but in Australia, it meant that some owners were never seeing sixth gear.

The solution was to tale the vehicle back to Toyota for a reflash of the on-board computer which would then instruct the transmission to select top gear at 95 or 100km/h. If this reflash hasn’t been performed, you might find that the vehicle has never actually selected top gear in its life. Definitely look into this possibility before spending money on transmission services or anything mechanical.

If the shuddering isn't getting worse I would probably persist with it until it starts to slip. If it slips, then definitely replace it.

While most automatic transmissions today are sealed for life and carmakers say they don’t need any servicing it pays to be cautious, especially when towing as you do. The guys at AW Automatics say it holds 8-9 litres, the service fill is three litres, and you should use Toyota WS trans fluid if its in warranty, and Valvoline Synthetic Trans Fluid if its out of warranty.

There should be a plug on the side of the transmission that you can use to check the trans fluid level. It’s unusual to strip teeth off the crown wheel; we haven’t had any other reports of that problem on the Landcruiser.