questions about cvt

[kjharry]

I am new to cvt transmissions,though I have done a bit reading about them and understand how they work.My Micra has a noise at crawling traffic speeds,on and off the throttle,which I can only describe as a sort of graunching,possibly the magnetic clutch grabbing an letting go?,or maybe the brushes?
Also do these clutches slip with age?,when pulling away at roundabouts etc,the car doesnt really take off well,the engine is fine,no misses or anything,it just seems a little slow moving off.At motorway speeds the car doesnt hold its speed well either,4000 to 4.5000 revs at 55 to 60 mph depending on the gradient,does that sound right? Any help will be apreciated,thanks guys.

 

[Stuart]

hello,
i have a cvt micra too and i too have this noise on the gearbox but i've had the car about 2 years now and i've had it checked everytime its in the garage (which isnt often thank god). as for not holding speeds and pulling away. there is a bunch of electrical connectors located on the outside of the gearbox underneath the battery which is a service item every 27000miles. try changing this if you havent. i did and it solved my gearbox troubles.
let me know what happens

 

[kjharry]

Hi, thanks for the reply,so what is the bunch of electrical connectors?,what do they do and what is done to them in a service?

 

[squigbobble]

Nice to find I'm not the only CVT Micra driver on the planet :grinning:

If he means the clutch brushes then they just get replaced once they're worn down to the minimum thingy, if they're knackered the clutch won't be able to grip properly and it'll slip more than it's supposed to. My 1.0 auto is pants at motorway speeds with 4 people in it 'cos it's revving waaaaay past the peak torque region just to get up to 70 on the flat. With just me in it, it's not so bad but CVT Micras just don't seem to like hills too much. I also find that my gearbox fannies around a lot if I try to pull away quickly from a standstill but I think that's just the programming. I haven't noticed any 'graunching' from mine but it's always whistled at low speed with no throttle, anyone else get that?

 

[kjharry]

Mine is a 1.3 engine,I think what I may do is find one in a garage for sale and take it out for a drive to compare it to mine,see how it drives.

 

[Stuart]

Mine is a 1.3 too, and yeh i was talking about the clutch brushes. they're just bolt out bolt in job and regularly get skipped on a service so its always worth checking them!

 

[Fordy]

i agree with Stuart there common to go on the k11 cvts have a look in a haynes to see if it has the measurement in it then take yours out then check the length of them

 

[squigbobble]

i agree with Stuart there common to go on the k11 cvts have a look in a haynes to see if it has the measurement in it then take yours out then check the length of them

It's even easier than that; Mr. Haynes says they have a wear indicator on them, so if there isn't one they'll've worn past it.

 

[kjharry]

Bugger me,I found out today what the problem has been with the car.Driving along the m4 today the exhaust started blowing,then the back box fell off.I stopped to have a look and make it safe.When I drove away it sounded like a tank but went like #### off a shovel,what a difference!Pulls like a train,80mph no problem.When I got home I had a look at the backbox,the silencer material (wadding) seems to stuffed full in the bore of the tailpipe causing a back pressure up the system?,whatever,it is much better,new backbox tomorrow and hopefully problem solved.

 

[squigbobble]

Hmmm... drop the silencer off, will have to try that sometime. One advantage of having CVT when doing this is that u can more easily live with loss of low end torque :upside: