CVT Brushes pics for you...

madmezza

Ex. Club Member
Hi All

Just took my CVT electromagnetic clutch brushes out this morning to check out the wear, and I took a few pics with my phone (couldn't find my DSLR camera!!).

The first one (Brushes.jpg) shows the brushes removed from the gearbox - you can just see the wear lines towards the top end (the holder end) of the brushes - in this instance, the wear is no where near the mark.

The second one (Brush Hole.jpg) shows the hole that they came out of (The Haynes Manual just says "remove the brushes" but doesn't tell you where they are - they're on the top of the gearbox, to the left of the battery base. It's a little difficult to see, but it's about in the middle of the picture. I took it a bit of a distance away so the fuse holders serve as a reference point. Note that it's a bit awkward to get the brushes in and out, and they are quite fragile, so be careful.

The third one (Clutch Contact Wheel.jpg) shows the innerds of the hole that the brushes came out of. A guy at Nissan told me that if it's all black in this hole then there's been lots of arcing and the electromagnetic clutch most likely needs replacing. The part alone is £900+VAT, so it's most likely that this will be the end of the car!! This is what I was worried about - as you can see from the picture, the two clutch contact wheels are nice and shiny (boy, was I relieved!!!)

Hope this may help anyone who wants to play with this part. If I replace any more bits, I'll try and take some better pics and post them on here. If you want to check anything, feel free to contact me (PM/email, or just post).

Rich
 

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squigbobble

Guest
Nice one, now I know what I need to look for :) Do urs have 45k of wear? It'll be interesting to see how mine compare with 74k of wear.
 
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madmezza

madmezza

Ex. Club Member
It's either 42k or less than 15k (I bought the car on 15k and I haven't changed them) - 99% sure it's 42k!

I'd be interested to see yours on 70+k miles as well. Also, if you get a chance, shine a light in the hole they come from an check the discs to make sure they're not black. Can you let me know what they're like?

The job took me about 30 minutes. Just be careful with the brushes as they're brittle and getting them out into the open involves a bit of awkward twisting. Also, there's some resistance as you put them back in (they're sprung against the clutch wheel) - just push against this to secure it in.

Rich
 
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squigbobble

Guest
How hard can it be to undo 2 bolts?! I can get at them from the left but there's not enough space to turn the spanner/ratchet, even with the battery tray off it's the same coming at them from the right :doh: I tried to attack it with the ratchet CV joint attachment but ran out of daylight and had to put the car back together while I could still see what I was doing :( Blast my pants mechanicery skills.
 
Errm this may sound stupid but what does that bit do? My Micra is on 74K does it need changing on mine as well?

Cheers
 
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squigbobble

Guest
neds said:
Errm this may sound stupid but what does that bit do? My Micra is on 74K does it need changing on mine as well?

Cheers
As silver si said, it's only a component of the automatic transmission. I'm actually trying to find out how worn it is so I can determine if it need changing.
 
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madmezza

madmezza

Ex. Club Member
Hi Squigobble

I did one of the nuts with a small ratchet, and the other I just undid a tiny bit with the ratchet, then sort of did it with a combination of by-hand (with the socket-set end on) and various angles with the tools from the socket set! It was hassle, but once it's vaguely hand loose you can get it off.

As for what it does (someone else asked the question). Drive from the engine is transferred through the gearbox via a magnetic clutch (for CVT auto gearboxes) - this is basically 2 metal discs with a load of iron filings in between (it's a bit more technical than that). When you power up the electromagnets in the disc, the powder goes "solid" and the power is transferred. The brushes are used to get power to the discs (which rotate) to power the magnets. Hence, if the brushes wear, it's a bit like clutch slip in a manual.
 
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surrey-dad

Guest
Calling all CVT owners out there... HELP !

Just took my CVT electromagnetic clutch brushes out this morning to check out the wear, and I took a few pics with my phone (couldn't find my DSLR camera!!).

...The third one (Clutch Contact Wheel.jpg) shows the innerds of the hole that the brushes came out of. A guy at Nissan told me that if it's all black in this hole then there's been lots of arcing and the electromagnetic clutch most likely needs replacing. The part alone is £900+VAT, so it's most likely that this will be the end of the car!! This is what I was worried about - as you can see from the picture, the two clutch contact wheels are nice and shiny (boy, was I relieved!!!)

Hope this may help anyone who wants to play with this part. If I replace any more bits, I'll try and take some better pics and post them on here. If you want to check anything, feel free to contact me (PM/email, or just post).
Rich
Hi Rich - Not sure if you are even a K11 owner anymore, as this reply is over a year late - but have found very view other threads on CVTs on the net.

Was wondering whether any other CVT owners could help out, as my local Nissan and indie garages only seem interested in me changing the whole electromagnetic clutch at ££££ !!! Mention undoing two bolts and replacing the brushes and they go all vague - little profit margin in it for them I suppose.
My local Nissan parts department even said they have never heard of such a part, and couldn't be a service item. :mad:

So does anyone know :
- part number of carbon brushes unit ?
- its approx cost ?
- or fully inclusive what would expect to pay for supply and fitting?

Many thanks for any additional info...

Andy
 

Fordy

Ex. Club Member
My local Nissan parts department even said they have never heard of such a part, and couldn't be a service item. :mad:

So does anyone know :
- part number of carbon brushes unit ?
- its approx cost ?
- or fully inclusive what would expect to pay for supply and fitting?

dont know if these are still avaible from nissan anymore, but i know when you could get hold of them, you had to solder them in as you dont get the whole thing
 

Ed

Fusion Motorsport
MSC Founder
Official MSC Trader
That looks very similar to the brushes inside an alternator. I wonder weather you could steal brushes from something like that..

Micra2007, if its the brushes then you may beable to replace them or has the clutch totally burnt out?
 
Thankyou for the brush info

I Sometimes find mine a bit difficult to change from N to R or D after it has been driven for a while, could this be an impending brush or clutch problem ?

Its perfectly smooth to change from n to D or R when it is cold or warmimg up, I mainly notice it when I'm parking after a journey, its like the shift lever is getting impeded a bit when accessing the opposite gear direction

There's no noise when this happens and it performs very well otherwise.

*EDIT*

Just found this excerpt in a nice old post by squigbobble

it can also be difficult to select D or R from N 'cos the teeth on the cogs (CVT still has a few, lol) have lined up funny, I find applying more force and a bit of verbal abuse does the trick and I haven't broken it yet. It's very normal for the gearbox to whistle at low speed, especially going downhill with your foot off the gas,
Hopefully what I have asked about is purely down to the same, it has only done 30k

..............& I was wondering about the whistle lol :laugh:
 

Ed

Fusion Motorsport
MSC Founder
Official MSC Trader
You snapped the steel belt????

You need a new gearbox then im afraid.
 

Gurpreet

Ex. Club Member
Club Member
^he's right... I'm only realising now how poorly the CVT boxes are made... proper boxes have 1, 2, 3 to select as well as D... I opened my leaking gbox and it fell apart.. once open it is a mission and a half to get the steel belt/plates set and adjusted...

a few general rules to look after cvt...
- always change gear when stationary.. not while moving or slowing down..
- dont knock it into neutral when decelerating to a red traffic light
- if you are rev happy, a speed freak etc. you need to check your gbox oil regularly... i usually do this when i change the engine oil every 6 months... yearly is sometimes too late depending on how you drive.. and v.important.. avoid over-filling!
- check carb. brushes every 27k miles or 2 years whichever comes first..

what cable??
 
has anyone got any picturs on how to remove powder clutch ?

You snapped the steel belt????

You need a new gearbox then im afraid.
no the gear selector cable got a new one it goes in reverse and 1 and 2 but not drive and you still have tom rami it in
 
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