# CVT transmission maintenance



## noah00 (1 mo ago)

I’m new to posting in forums, so I apologize in adVance for any faux pas. I have a 2017 Sentra with a CVT transmission, which I have apparently and unfortunately woefully neglected. It has roughly 110k on in, without any major issues. I just recently noticed a slight hesitation/chatter, from transmission if I am being aggressive with the pedal from a stop. If I am driving easy on the pedal (typical of my driving habits) I have no issues. However, this slight issue has sent me down the wormhole of terrible CVT transmission stories. I have called some service places, and taken it to a dealership, and they tell me a disclaimer, that if I change my fluid now, It could possibly make matters worse Changing the fluid. This seams pretty contrary, however since I am not a mechanic, I tent to listen to the professionals. Now I’m stuck between a rock and a hard place. Would it be be better at this point to just bite the bullet and change the fluid, or have I pretty much sealed my transmissions fate, and just run it to the point I have to replace it. (Expensive learning curve).

Any suggestions to help me get over the hurdle is much appreciated


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## VStar650CL (Nov 12, 2020)

You can't hurt most CVT's by changing fluid like you can hurt a regular A/T, for the simple reason that a CVT has almost no clutch material. Since spent clutches and bands are the prime ingredient in "ATF soup", CVT's can't make any, and that means there's little risk of a fouled Valve Body.

That said, your Sentra does _not_ have a true CVT tranny. It's a hybrid arrangement with high and low ranges, and the planetaries that shift between high and low _do_ have a clutch that wears out. However, it still has a belt, and that means not changing the fluid is a certain death sentence. It's a metal belt riding on metal pulleys, so the only thing protecting metal from meeting metal is the quality of the fluid. That means the equation is excruciatingly simple: When the fluid dies, so does the tranny.

With that for background, my professional advice is to change it. You _might_ have a worn out planetary and enough crud in there to damage the Valve Body, but that's a maybe. The belt isn't a maybe, it's doomed for certain without fresh fluid. So try a change and see if it helps. It's really your only hope. If it doesn't help, then the judder you're feeling was simply a sign that it was already too late.


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## noah00 (1 mo ago)

I defiantly appreciate the info. I’m pretty mechanically inclined so I think I’m going to just do it myself. I regularly drive trucks and jeeps, this is my first sedan. So was completely unaware of the CVT thing. 
Mia there any opinions on CVT fluid. I know Nissan has their NS-3, however I see that Valvoline’s CVT fluid ranks pretty high on consumer lists. Any issues with deviating from OEM fluid?


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## VStar650CL (Nov 12, 2020)

Valvoline and Indemitsu are both decent but noisy just like NS3. My customers using aftermarket fluids have had the best things to say about Eneos or AMSoil, both run quiet and have some important specifications like film strength which exceed NS3. I get NS3 heavily discounted working in a dealership, but if I was buying fluid at retail my choice would be Eneos Eco.


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## noah00 (1 mo ago)

Last question, and I think I’ve got a handle on my situation. I warmed the car up, ran thru the gears, and drained the fluid. About a half quart came out with the pan bolt, and two additional quarts when 5mm overflow bolt removed, for a total of roughly 2.5 quarts drained. Fluid was dirty, for sure, but no metal or clutch particles visible in the fluid. (Promising) I filled with 4 quarts of Amsoil CVT, ran for about 20 min, switching thru gears. I then shut off engine, and removed pan bolt and let drain out till just a drip ( leaving overflow bolt in place ) That left me with 2 quarts drained out. That puts me at about 1/2 different ( lower ) than what I originally drained out of the transmission.

The difference in fluid levels has me scratching my head.since there is no dipstick, I can’t get an accurate read on levels. Everything I’ve read and watched, between 2 and 4.5 quarts drain out of these Sentras. 
So my question is, should I make sure I put as much back in, as I removed, or is the overflow bolt a reliable indicator of internal fluid levels.
(Think I even read somewhere it’s better to be a little low, than over fill these cvt’s) 

Again, your input is greatly appreciated


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## VStar650CL (Nov 12, 2020)

The Sentras are bottom-fill, so you should have the right level in it now. The drain tube doesn't lie provided the car was level as well as warm. Sounds like it was a bit over before you did the change.


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## VStar650CL (Nov 12, 2020)

noah00 said:


> (Think I even read somewhere it’s better to be a little low, than over fill these cvt’s)


Way better. It won't even notice half a quart low, and the Sentra units are a bit more tolerant of overfilling than the RE0F10x's. But only a bit, a quart over is still a death sentence.


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## noah00 (1 mo ago)

Great. Defiantly made sure I was on a level surface. Some of the tutorials said leave the car running when you level fluid out, some say to turn car off. It added some confusion. The transmission has even quieted down some. I plan to do another fluid change in about another 10k, just to get more of the old fluid out, then switch to further intervals. 

Youve been a big help VStar650cl. Thank you.


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## VStar650CL (Nov 12, 2020)




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## noah00 (1 mo ago)

Ok, I do have one more question. Just for best practice sake, is it better to level cvt fluid off when engine is parked in idle, or when engine is off. I can find info supporting both, but most seam to do when car is running. I’m a stickler for doing thing the textbook way.


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## VStar650CL (Nov 12, 2020)

Oh, I didn't catch the "running" part, sorry. Leveling for the RE0F11x is done with the engine _stopped, _not running like you'd do on a 10D. The 10D's don't have an overflow tube, they use a leveling plug instead. That's probably what's confusing you online. Here's the procedure straight from the horse's mouth. Refilling from the top, you put in about the same 3 quarts and just skip all the charge-pipe stuff.


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## noah00 (1 mo ago)

Ok, so I read thru this quite a few time. So it looks like this instructs to repeat one drain and fill (line 17), that make sense to me, kinda like an old school flush. However it does state,(line 28) about leveling off fluid: *caution perform this work with the vehicle idling. *

now I did somewhat of an experiment before I posted that last question. I leveled car again, and while transmission at temp, added another liter of cvt fluid. I let it run for a bit, and shifted thru gears, with foot on brake and parking break on. I then pulled drain plug ( with car idling and overflow tube still in place) and only a bit of fluid came out. 
With this process, the car seamed to vibrate quite a bit more when in gear than I have previously noticed before. Almost jumpy when put into gear. I wasn’t comfortable with that, so drained the excess with engine off, as with my first swap. it seamed to smooth out again. Thus the hunt for the exact process for leveling fluid. 

I still have quit a bit of new CVT fluid left, so I think I’m going to repeat the process anyway. Maybe adding just shy of 3 liters. Trying to error on the little bit low on fluid side.


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