CVT - What are the most miles anyone has with no trouble?

[LUVMYALTIMA]

I actually need some advice. My 2007 Altima has really never had any problems until this weekend. I did change the CVT oil/radiator fluids about two years ago and have driven about 50K miles since then. This weekend we were driving back to Arizona from the California beach when about 50 miles east of Blythe (in the middle of nowhere) the overdrive kicked off and the RPM's went up. We had no choice but to keep driving, where are we to get help in the middle of nowhere? The closest town with any kind of real help was Buckeye. So, we drove the car at about 50-60 mph the rest of the way to Buckeye. There the guy at checkers read the codes and one of them was a transmission heat sensor and the other the transmission solenoid. The transmission dip stick reaked like burned transmission fluid. Given that we were still about 70 miles from home he recommended just letting it cool off and then driving it home. We did that. It cooled off and now doesn't have a problem. However, I took it in to the dealer and they say that it needs a new transmission and want about $4000 for it. Of course, as my luck would have it, I have 132K miles on the car and so nothing is covered under warranty. My questions is if the transmission is ruined why does it still run and why won't anyone change the stinky tranmission fluid and let me ride the thing until I can save up the remaining $1500 for the repairs? I have been told by the dealer that nobody other than the dealer should change the transmission oil because they will do it wrong and ruin the transmission. What makes it so hard to change the transmission fluid yourself? I have read posts on this site where people have done them successfully without their transmissions blowing up. I just wish the transmission would have given us a sign of impending doom but to just up and die seems a bit strange. The fluid levels were exactly where they should be. Makes me wonder if the thing just got too hot but would still work now? What do all of you experts think?

[kerrton]

Just to be clear, this is the CVT transmission, correct?

The CVT is a bit unique, the best reason to let the dealer change the fluid is because there are no aftermarket fluid alternatives, you must use the Nissan NS-2 fluid. There is then the decision of doing a basic drain and fill, which will leave a good portion of old fluid behind, or to do a power flush which will fully replace all of the old fluid and remove all contaminants prior to filling with fresh fluid. The power flush should be done by Nisaan, it is not the same as a regular conventional trannny fluid flush.

As for whether to replace or not, only the dealer knows the details of the diagnosis. You need to ask them for the details of their findings and justification of the diagnosis, that "the transmission is ruined and must be replaced". They'll be happy to explain to you the details of the damage, asking us on this forum is just asking for speculation. I can speculate that you've had an overheated CVT due to fouled fluid that no longer lubricates and cools as designed, and provided no catastrophic damage has been done (which seems to be the case, since you report that you can drive the car and it operates normally?), I would say a fluid flush and replacement should be all you need. Again, we can speculate but you need to ask your dealer if they can simply change the CVT fluid considering the transmission seems to operating well, and if not, they need to fully explain why the CVT must be changed, indicating specifically what has failed and how they determined this.

Let us know how it turns out.

[Criiperdan528]

Mine hit 61000 and the trans went out

[Towncivilian]

There is then the decision of doing a basic drain and fill, which will leave a good portion of old fluid behind, or to do a power flush which will fully replace all of the old fluid and remove all contaminants prior to filling with fresh fluid. The power flush should be done by Nisaan, it is not the same as a regular conventional trannny fluid flush.

No shop does a "power flush". I've never actually seen or heard of any shop having a machine that forces fluid through a transmission at a high pressure. Transmission fluid exchanges use the transmission's own pump and the machine used is simply a bladder for new and old fluids with adapters for the transmission cooler lines for proper connections. Even the factory service manual, page MA-30, mentions simply disconnecting the cooler return line to evacuate old fluid as you fill with new fluid via the transmission charging pipe (dipstick). You can do this easily in your driveway (well, with some slight modifications to the procedure) but on a CVT I would absolutely only have Nissan do the service as you can potentially lose the CVT warranty otherwise. For a conventional automatic transmission? I'll stick to my driveway.

[sstroudwku]

I actually need some advice. My 2007 Altima has really never had any problems until this weekend. I did change the CVT oil/radiator fluids about two years ago and have driven about 50K miles since then. This weekend we were driving back to Arizona from the California beach when about 50 miles east of Blythe (in the middle of nowhere) the overdrive kicked off and the RPM's went up. We had no choice but to keep driving, where are we to get help in the middle of nowhere? The closest town with any kind of real help was Buckeye. So, we drove the car at about 50-60 mph the rest of the way to Buckeye. There the guy at checkers read the codes and one of them was a transmission heat sensor and the other the transmission solenoid. The transmission dip stick reaked like burned transmission fluid. Given that we were still about 70 miles from home he recommended just letting it cool off and then driving it home. We did that. It cooled off and now doesn't have a problem. However, I took it in to the dealer and they say that it needs a new transmission and want about $4000 for it. Of course, as my luck would have it, I have 132K miles on the car and so nothing is covered under warranty. My questions is if the transmission is ruined why does it still run and why won't anyone change the stinky tranmission fluid and let me ride the thing until I can save up the remaining $1500 for the repairs? I have been told by the dealer that nobody other than the dealer should change the transmission oil because they will do it wrong and ruin the transmission. What makes it so hard to change the transmission fluid yourself? I have read posts on this site where people have done them successfully without their transmissions blowing up. I just wish the transmission would have given us a sign of impending doom but to just up and die seems a bit strange. The fluid levels were exactly where they should be. Makes me wonder if the thing just got too hot but would still work now? What do all of you experts think?

What has happened to your transmission is the valve body has sustained damage and is no longer allowing the torque converter lockout solenoid to engage. They are indicating you need a new transmission because the DTC P0744 in the system has a TSB applicable to replacing the unit. Now You can have them pull a TSB for a 2007-2009 Altima that indicates replacing the valve body itself. This part is around $800 and only takes around 2hours to service. However, this may only be a temporary fix to a long term problem.

Just to be clear, this is the CVT transmission, correct?

The CVT is a bit unique, the best reason to let the dealer change the fluid is because there are no aftermarket fluid alternatives, you must use the Nissan NS-2 fluid. There is then the decision of doing a basic drain and fill, which will leave a good portion of old fluid behind, or to do a power flush which will fully replace all of the old fluid and remove all contaminants prior to filling with fresh fluid. The power flush should be done by Nisaan, it is not the same as a regular conventional trannny fluid flush.

As for whether to replace or not, only the dealer knows the details of the diagnosis. You need to ask them for the details of their findings and justification of the diagnosis, that "the transmission is ruined and must be replaced". They'll be happy to explain to you the details of the damage, asking us on this forum is just asking for speculation. I can speculate that you've had an overheated CVT due to fouled fluid that no longer lubricates and cools as designed, and provided no catastrophic damage has been done (which seems to be the case, since you report that you can drive the car and it operates normally?), I would say a fluid flush and replacement should be all you need. Again, we can speculate but you need to ask your dealer if they can simply change the CVT fluid considering the transmission seems to operating well, and if not, they need to fully explain why the CVT must be changed, indicating specifically what has failed and how they determined this.

Let us know how it turns out.

The CVT operates around 1000psi, the pressure plates require a lot of pressure in order to keep the belt tight on the 2.5. There is no way to powerflush a CVT. We do an inline system flush on our standard transmissions by tapping inline with the transcooler lines. To properly exchange the fluid is to drain it, fill it, run it for several thousand miles and repeat. But at $250 a service this gets expensive. You can get a more comprehensive drain and fill if you request your valve body dropped so all the fluid and drain above it, then you just have the torque converter with old fluid.

[Cowman15y]

I have an 08 3.5 sedan....bought it with 60k on it put 10k so I'm sitting at 70k .....haven't even heard a funny noise yet