Cvt ; why some fail while others keep going

[old tech]

A while back Ronzuki had asked why some of these Cvt‘s fail while others keep going. At the time I couldn’t answer this because I really didn’t know but after dismantling about 50 of these transmissions and rebuilding about 10 I did learn a lot of interesting things. One of the things I learned is how to gain access to the primary without a full tear down and I can get there and modify the primary, converting it to long pin while only spending about an hour and a half. Now I take a used transmission and inspect and convert it before putting it back into service but to answer the question, some of these primary units are a very close fit while others start out with a little more clearance. The tighter yet still more freely the longer lasting it will be. for the Kizashi this primary unit at best is a bit weak for this car. Once the balls start wearing it rapidly gets worse dropping pieces of steel into the back of the transmission pan will be your first clue. I wanted to post some pictures of the peeling that happens on these balls but I still can’t figure out how to do pictures. sorry. After this process starts it quickly gets worse and then the ball snaps in half and the drum section of the primary tries to run over the ball snapping the drum and trashing the shaft. These parts are not available new and can only be scavenged from another unit. There’s also a concern of all the metal that went through the other pieces of the transmission mainly the flow control valve. So the factors that determine long life of a CVT transmission are as follows. 1 Original fit of primary . 2 Maintenance or lack of. 3 How hard it’s used . Load and hard acceleration from a stop.





Sent from my iPhone using Tapatalk. These pictures are of a used transmission that had 110k miles on it . The shaft and drum were in perfect shape still and ready to convert or upgrade to long pin. These next photos show true damage that happens with more miles , eventually snapping the balls in half causing drum to run them over and breaking.. The best advice I can give you is to service every 30k miles and pull pan inspect debris. The silver chips found in the rear of the pan are indication that the balls are failing and could be saved if trans isn’t run too much longer. . Here is what a long pin looks like . 1 pin replaces 2 balls . 3 pins needed in the primary unit.

[Ronzuki]

Excellent...thanks for the explanation, and, the pics! Now that I can see exactly what this ball to pin conversion is, Why the hell it wasn't long pin from the get go is a mystery to me.

So the factors that determine long life of a CVT transmission are as follows:
1) Original fit of primary - Guess mine is pretty good, IDK.
2) Maintenance or lack of - Again kicking myself for not listening to my gut and waiting so long. That is now remedied.
3) How hard it’s used . Load and hard acceleration from a stop. - I run it hard once it's rolling for sure. NEVER shifted it when rolling (always firm brakes applied) and never jack rabbited it from stand-still since day one.

I assume that 'original fit' is likely the primary determining longevity factor really. That makes sense as I've stated before the early Japanese built MYs seem, to me at least, to be holding up better than the latter Chinese built MYs. Tighter fit puts excessive pressure on the balls causing them to delaminate...assuming they were of quality metal and manufacture in the first place. On those tighter fit units, that haven't grenaded yet... isn't putting the long pins in going to have some type of detrimental wear effect then on potentially the trans parts themselves?

[KlutzNinja]

Thanks for the write up, although a lot of this is beyond my understanding lol. I have 61k miles on my car so I’d like to hope I’m okay for a little while, but the CVT was always my primary concern with longevity as far as getting a Kizashi went. Before I got my Kizashi, I kept hearing how JATCO CVTs in Nissans were dying a little past the 100k mile mark, and assumed the Kizashi could be in a similar boat. But I love the Kizashi so much that I got one anyway.

With your remark about getting the car serviced every 30k miles or so, I’m wondering what kind of mechanic would be suitable for inspecting the CVT? Like should I go to a transmission specialist, an independent Nissan/Japanese car mechanic, Suzuki service center, etc.? Or would your everyday trusted mechanic be fine and would know what to look for?

Thanks again.

[OliverB]

Thanks for the write up, although a lot of this is beyond my understanding lol. I have 61k miles on my car so I’d like to hope I’m okay for a little while, but the CVT was always my primary concern with longevity as far as getting a Kizashi went. Before I got my Kizashi, I kept hearing how JATCO CVTs in Nissans were dying a little past the 100k mile mark, and assumed the Kizashi could be in a similar boat. But I love the Kizashi so much that I got one anyway.

With your remark about getting the car serviced every 30k miles or so, I’m wondering what kind of mechanic would be suitable for inspecting the CVT? Like should I go to a transmission specialist, an independent Nissan/Japanese car mechanic, Suzuki service center, etc.? Or would your everyday trusted mechanic be fine and would know what to look for?

Thanks again.

Sadly, the primary and secondary pulley assemblies cannot be inspected until the whole transmission is out of the car. You would be lucky to find a garage that is even willing to touch the car to begin with. The transmission isn't even unique to the car, but Suzuki being out of the continent and the lack of spare parts is one hell of a turn off. Your best bet would be a former Suzuki dealer or someone such as old tech.

On those tighter fit units, that haven't grenaded yet... isn't putting the long pins in going to have some type of detrimental wear effect then on potentially the trans parts themselves?

I'm no engineer, but I think neither option is ideal given what we have. The pins allow you to have more surface area and they cannot be crushed at the detriment of being unable to move up and down. The balls can move in every direction, but they will wear out, they do not fill all the space in the groove and they are not "secured" like a caged bearing would. I believe the pins, despite being allowed to rotate on one axis, is the better solution.





Take a pen (pin) and place it between your hands (pulley assembly). If you move one hand forward, the pen will start to rotate. Now do the same thing and move it upwards at the same time. The pen will still rotate and your hand can still move upward.

[Ronzuki]

The CVT was a def point of contention for me when I purchased the Kiz (new) as well. After test driving the car, it was extremely hard to walk away and finally squashed my 'fear of the unknown' when, after they saw me capitulating, they threw another 500 (I think it was) in for the soon to be seriously screwed Heep Rubicon I was focused on unloading.

Now I'm just enjoying driving the car and to hell w/ worrying about the trans. It is what it is. I'll change the fluid out again in the spring and run her hard til she dies, grinning the entire time. If OldTech was closer I might have considered some preemptive measures at the prices he'd mentioned in another thread, but he's not. My pan and pickup screen were perfectly free of any metal flakes/chips and the magnets had only gray goo w/ mild glitter to it finer than the paint's metallic flake, so, she's got years and miles left in her yet.

[SAEED_KIZZY]

With your remark about getting the car serviced every 30k miles or so, I’m wondering what kind of mechanic would be suitable for inspecting the CVT? Like should I go to a transmission specialist, an independent Nissan/Japanese car mechanic, Suzuki service center, etc.? Or would your everyday trusted mechanic be fine and would know what to look for?

Thanks again.

for me this forum is the best adviser to maintain my car better than any mechanic around.

[old tech]

The things that you have done to your car , you are more than capable to do the routine service yourself. Drain fluid. Remove all pan bolts except one or two on the front letting remaining fluid to drain out the rear, then remove last bolt and carefully lower pan without disturbing contents and examine any debris in mainly rear of pan and pickup screen. The dark grey metallic silt on the magnets is normal , they shouldnt look like a donut though. On the screen, what you are checking for and hope that you dont see is a non metallic black powder or fuzz in addition to the silver and chrome chips in rear of pan . That would indicate the teflon sealing ring in the primary is getting a hard workout from the primary wobble. A transmission shop is used to having to stand behind the complete trans and nearly always is going to sell complete overhaul. My take on these is that the primary fails to early .The rest of the trans is pretty solid. Going in and replacing balls or upgrading to long pin is doable. Later i plan on listing a detailed post on how Im doing the job so that someone that has done some trans work before could do the job. It does require some skill.

[Ronzuki]

OT, thanks again for all of the observations and details you've provided as a result of your experiences tearing in to several of these transmissions. It is valuable information to share. I / we very much appreciate the time you've put in to your postings here and answering questions with candor and insight.

[LPSISRL]

Thanks for this. Were any transmissions manufactured with pins instead of balls? If some were, is there any way to know? Also, where did this update come from? Doesn't seem like someone with a lot of time on their hands figured this out and started making their own pins. Was this a rebuild retrofit?
Thanks!

[LPSISRL]

Thanks for the write up, although a lot of this is beyond my understanding lol. I have 61k miles on my car so I’d like to hope I’m okay for a little while, but the CVT was always my primary concern with longevity as far as getting a Kizashi went. Before I got my Kizashi, I kept hearing how JATCO CVTs in Nissans were dying a little past the 100k mile mark, and assumed the Kizashi could be in a similar boat. But I love the Kizashi so much that I got one anyway.

With your remark about getting the car serviced every 30k miles or so, I’m wondering what kind of mechanic would be suitable for inspecting the CVT? Like should I go to a transmission specialist, an independent Nissan/Japanese car mechanic, Suzuki service center, etc.? Or would your everyday trusted mechanic be fine and would know what to look for?

Thanks again.

Sadly, the primary and secondary pulley assemblies cannot be inspected until the whole transmission is out of the car. You would be lucky to find a garage that is even willing to touch the car to begin with. The transmission isn't even unique to the car, but Suzuki being out of the continent and the lack of spare parts is one hell of a turn off. Your best bet would be a former Suzuki dealer or someone such as old tech.

On those tighter fit units, that haven't grenaded yet... isn't putting the long pins in going to have some type of detrimental wear effect then on potentially the trans parts themselves?

I'm no engineer, but I think neither option is ideal given what we have. The pins allow you to have more surface area and they cannot be crushed at the detriment of being unable to move up and down. The balls can move in every direction, but they will wear out, they do not fill all the space in the groove and they are not "secured" like a caged bearing would. I believe the pins, despite being allowed to rotate on one axis, is the better solution.





Take a pen (pin) and place it between your hands (pulley assembly). If you move one hand forward, the pen will start to rotate. Now do the same thing and move it upwards at the same time. The pen will still rotate and your hand can still move upward.

This picture helped me to understand what was going on. But isn't the diagram rotated 90 degrees?