The Sunday News
Lovert Mafukure
Many of our readers seem to be having trouble with Nissan CVTs. Many manufacturers have adopted the CVT technology, among them is Nissan and Nissan is feeding people more beans than enjoyment!
We have had many stories with Nissan and now someone is wondering whether they can replace their Nissan liberty CVT with an automatic transmission because it is what they can find.
There is a lot that goes into making a car run and nowadays computers do most of the work. For us to get to a point of understanding whether an automatic transmission will work in place of the original CVT we need to understand how the whole system works. By the way, CVT stands for continuously variable transmission.
A CVT is a transmission that changes without steps eliminating the need for gear changes. It uses a system of belt-driven pulleys that change ratios to increase or decrease speed. This technology is supposed to improve engine fuel efficiency. It’s not really new technology but it has just been employed on smaller vehicles in the recent past. It is completely different from our traditional automatic transmissions.
CVTs ‘seem’ to fail prematurely but others have however given their owners a good run for their money. I say ‘seem’ because I believe the premature failure of these transmissions is mainly due to negligence. The problem with most of us is that we want maintenance free cars which do not exist. Given enough correct service and diagnosis when things go wrong, they can last the mile.
Technological changes have seen the design and manufacture of cars being changed as well. This technology is coming through improper channels mainly though the grey imports. That means there’s is a lot of ‘on the job’ training going on with your cars as experiments. Some mechanics do not catch on quick and end up treating these special transmissions the wrong way.
The Liberty has a front wheel drive setup with 4WD option. The front wheel D rive liberty is driven by a Continuously Variable Transmission while the 4WD has an automatic transmission. It’s kind of funny that Nissan knew from the start that the CVTs cannot handle that much strain that a 4WD setup brings so they put automatic on 4WD. The CVT is good and offers better fuel economy when its still in shape and smoother acceleration but for reasons better for your pockets, you are better off without it.
The problem with this car is that when the Continuously variable transmission (CVT) decides to give up the ghost, it plays an unpleasant and un-thrilling horror movie. The most common problem like this one is that when some things go wrong it goes into limp mode when hot and consequently loses power. Not much can be done to it when it starts acting shady like this except for replacement or repair depending on what exactly is misbehaving, the latter is quite a long short considering we are in Africa and again this is poached technology so spares backup can be a nightmare.
With that little understanding we can then look at whether it’s possible to swop an automatic into a car that was originally equipped with a CVT. When they made the CVTs they moved away from mechanical or hydraulic gear shift to more electronically control systems.
You will find that at times you may have an electrical malfunction in the transmission system with possible dead sensors that make it hard for you to drive since they won’t be transmitting correct signals for a smooth operation.
Speed sensors send signals to the computer and their computer with do the business of torque transfer from engine to the gearbox.
We have now established that the CVT is electronically controlled by use of sensors transmitting signals to the computer and consequently the computer controlling the torque transfer and ratio change. That means therefore an automatic transmission will not work without major work being done.
An automatic transmission from the same type of engine will mount up on the engine but getting it to work will require one to change the computer and wiring harness to accommodate an automatic transmission, this can easily end up costing more than the car is actually worth.
Since they are some liberties that are automatics, the easier way to go about it would be to look for a ‘donor’ car maybe from a junkyard or something that has been involved in an accident or scrapped for any other reason. That way you can transplant the wiring, computers and transmission to your car but the cost of buying a ‘donor’ car will be more than just replacing with another CVT.
When all is said and done, nothing is impossible. Given enough time and money that swop can be done but it entails changing a lot of things from the wiring harness to the transmission itself and computer.
At times you may have to change the drivelines as well. So, in the end it would be a costly job and the easiest way out would be to simply replace with another CVT…till next time. Happy motoring!
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