2001 Nissan Maxima -Transmission- Revs Rise, Speed does not

[District]

When driving for a period of 40 minutes +, usually on the highway, my 2001 Nissan Maxima transmission begins to "slip" (if you can call it that). Randomly, the car would fall into "neutral", and as I press the gas pedal down, the revs begin to rise to 5000-6000 RPM's, but the speed remains unchanged. To fix the issue, I shift into neutral, 1 or 2, slow down, and drive again but very carefully as to avoid further "slippage".
I do not have a "Check Engine Light", and this has happened to me three or four times, but it seems the frequency may be increasing because of the summer heat.

I have searched this forum thoroughly, and have read about issues with the Speed Senser and the Motor Mount. Upon reading that, I visited my mechanic today and told him about my problem and what solution may be (Speed Sensor replacement / Motor Mount). He told me that it has nothing to do with it and it is the just the transmission.

What do you guys think is the problem? If you have experienced this before, how did you fix it? What can I tell my mechanic specifically to look out for?

My problem is exactly same as the one portrayed in this video on youtube.

https://www.youtube.com/watch?v=3CbxKzxOh4g


Thank you ahead of time.

[samoneal]

Have you checked or replaced the Mass Air Flow Sensor?

[District]

SOLVED: My mechanic picked up the P0720 code on the diagnostic and we quickly replaced the "Speed/Revolution Sensor" located behind the wheel on the drivers side. Cost me $75 for labor and $119 for the sensor. The sensor was a bit expensive, could have picked it up for maybe half the price online, but I did not want to wait any longer to have it changed, since the slipping could have damaged the transmission very badly.

[Sawyer_]

How is the car now? Did the sensor replacement fix the issue?

[LGRANDIN]

thats common for the maxima's and ebay sells them for 20 bucks, you coulve saved some money just for future reference