CVT transmission

[desertdude]

6 hours ago, Fuad said:

I hope toyota did as when i went for servicing 2018 model corolla for service they were mentioning some items need to be changed and later dropped that telling me its not required as 2018 transmission is CVT. I am not sure.

Isn't that great, the stealers themselves don't know what transmissions their cars have.

[Barry]

@Rahimdad it was a DAF/Volvo 55 I had. I think it was a 71 or 72. I bought it from and old guy who wanted to restore it but he had a stroke. I bought it intending to put a big engine in it but there was no room to fit a pedal box so I had some fun with it and sold it to a guy from the Isle of Man on the internet. It was an early form of CVT. It had a rubber belt that used to slide between 2 cones as you drove different speeds. The fun part was that it would do the same speed backwards as it would do forwards. I tried it once and trust me, it was more scary than fun 😂

 

[desertdude]

2 hours ago, Barry said:

@Rahimdad it was a DAF/Volvo 55 I had. I think it was a 71 or 72. I bought it from and old guy who wanted to restore it but he had a stroke. I bought it intending to put a big engine in it but there was no room to fit a pedal box so I had some fun with it and sold it to a guy from the Isle of Man on the internet. It was an early form of CVT. It had a rubber belt that used to slide between 2 cones as you drove different speeds. The fun part was that it would do the same speed backwards as it would do forwards. I tried it once and trust me, it was more scary than fun 😂

 

That's exactly what even a modern CVT is, a belt with some metal keys driven between two cones. 

[Barry]

29 minutes ago, desertdude said:

That's exactly what even a modern CVT is, a belt with some metal keys driven between two cones. 

Same concept but 50 years later. Everyone thinks it’s a new modern thing. How did Nissan get it so wrong with 50 years of research behind them?

I got a Nissan in last week. CVT was faulty. Previous mechanic changed the transmission 3 Times and it wouldn’t work. 

Car came to me this week. I spent 10 minutes reprogramming the transmission and it worked perfectly. 

If only people would spend a few hundred extra dhs to pay for someone who knows what they’re doing instead of paying 50dhs to a monkey in rashidiya with a computer, their life would be easier  

I charge a bit more but you don’t have to deal with bulshit mechanics or wrong diagnosis. 

[desertdude]

33 minutes ago, Barry said:

Same concept but 50 years later. Everyone thinks it’s a new modern thing. How did Nissan get it so wrong with 50 years of research behind them?

I got a Nissan in last week. CVT was faulty. Previous mechanic changed the transmission 3 Times and it wouldn’t work. 

Car came to me this week. I spent 10 minutes reprogramming the transmission and it worked perfectly. 

If only people would spend a few hundred extra dhs to pay for someone who knows what they’re doing instead of paying 50dhs to a monkey in rashidiya with a computer, their life would be easier  

I charge a bit more but you don’t have to deal with bulshit mechanics or wrong diagnosis. 

I think the design itself is flawed. All the power is being transferred through a tiny mostly rubber belt slipping and sliding on two cones. 

For low power applications it might work and I mean 2 wheel moped type stuff. There is a reason why there are no big power engines coupled with CVTs. I think the biggest motor with a CVT you can find is NA V6 just over 250hp

[M.K]

9 minutes ago, desertdude said:

I think the design itself is flawed. All the power is being transferred through a tiny mostly rubber belt slipping and sliding on two cones. 

On the other hand, a very similar technology has been used in the industry for many years. Use of gear boxes to take away the additional momentum when starting up, to allow smooth acceleration and to ensure accurate speed control. The technology is being replaced nowadays by the Variable Frequency Drive in many applications.

[Frederic]

9 hours ago, M.K said:

On the other hand, a very similar technology has been used in the industry for many years. Use of gear boxes to take away the additional momentum when starting up, to allow smooth acceleration and to ensure accurate speed control. The technology is being replaced nowadays by the Variable Frequency Drive in many applications.

PIV gearboxes were very popular in the days. We had only one mechanic who we trusted to service them.

http://www.corrugatedbox.com/gearbox.html

But yes, the VFD in combination with a normal gearbox has taken over most applications in the industry.

 

10 hours ago, Barry said:

Same concept but 50 years later. Everyone thinks it’s a new modern thing. How did Nissan get it so wrong with 50 years of research behind them?

I got a Nissan in last week. CVT was faulty. Previous mechanic changed the transmission 3 Times and it wouldn’t work. 

Car came to me this week. I spent 10 minutes reprogramming the transmission and it worked perfectly. 

If only people would spend a few hundred extra dhs to pay for someone who knows what they’re doing instead of paying 50dhs to a monkey in rashidiya with a computer, their life would be easier  

I charge a bit more but you don’t have to deal with bulshit mechanics or wrong diagnosis. 

Barry,

If the transmission needs reprogramming, is that due to a faulty original program from Nissan ? Or is that solely to match the newly installed transmission with the onboard program ?

 

[Barry]

11 hours ago, Frederic said:

PIV gearboxes were very popular in the days. We had only one mechanic who we trusted to service them.

http://www.corrugatedbox.com/gearbox.html

But yes, the VFD in combination with a normal gearbox has taken over most applications in the industry.

 

Barry,

If the transmission needs reprogramming, is that due to a faulty original program from Nissan ? Or is that solely to match the newly installed transmission with the onboard program ?

 

The transmission is coded to match the ECU. 

Its like getting a new girlfriend. You wake up one day after a few beers and there’s a different girl lying beside you. You’re going to think, hey, who is this, and there will be communication problems. 

When you change the transmission, the ECU is sending signals to the transmission and the transmission sends a signal back. The ECU says, hey, you’re not my transmission so they don’t communicate and work properly together. The ECU needs to be tricked into thinking the original transmission is installed in the car to work properly. This is why the coding from the old transmission is flashed to the new transmission.

This is a big problem with new cars I come across every day. Some cars require simple things like window motors to be recoded to suit the car. Some new cars won’t accept second hand electrical parts, even after recoding. Brand new, dealer only, and they still require coding after that.

I only work on classic cars now but I try to stay up to date with new stuff as much as possible and attend every course and seminar I can find. It’s getting harder and harder for the everyday mechanic to repair basic faults without having a degree in automotive or electric engineering. I only do it because you never know when the dream will end and you have to go back to the real world.