Have a 2000Nissan Maxima SE. When it is extremely hot outside and I drive more than 20 miles, I lose my gears. All of a sudden if I am starting to drive when the traffic light turns green, it winds out. I pull off road and put in park. After a couple tries it goes back into gear and seems ok til I get home. It only happens when it is very hot out. I recently had the transmission serviced and the tech said he say no problems.

If you just had it serviced and now having problems I would take it back and have him look at it. I'm assuming that you had no problems before the repair work. Simple things to check are fluid level and filter.

Thanks Mark. I did have the problem before the service was done. It only happens in the summer. So odd.

Does it do it when you first start up or only once its warmed up??

Only after I've been driving distance of at least 30 miles and the weather is in the 90's The car doesnt overheat but it must be the transmission fluid is getting to hot and not circulating properly. My friend said maybe the filter need to be changed.

Sounds like fluid might be a good place to start. When you have the pan off look things over real well. Look at filter and color of fluid. The fluid should be redish pink. If there is a lot of black debris in fluid you have excessive internal wear.

There is a separate transmission cooler within the radiator on 5th gen Maxima's with automatic transmissions. Check to see if its damaged or clogged etc. If it only happens on hot days this may be a problem because the fluid isn't being cooled properly. If the fluid gets too hot it will deteriorate and will not be effective, over time causing damage to the trans or severely limiting the life of it.

The loss of drive on really hot days above 36 degrees C occurred on my 2002 Maxi, both cooling system thermostats were found faulty one closed completely and the other half open I also had a new radiator installed , I had no re-occurence of the problem and the temp. indicator remains below halfway.