I saw a post some time ago concerning a problem with automatic transmissions and a slight increase in rpm as the transmission upshifts...can anyone redirect me to the cause? thx

 

search for that post then

 

RPM's go up when the tranny upshifts. Whats the problem? Is there a small lag when that happens? If thats what your feeling it's pretty normal for Nissan trannys. It's more of a slush box then a sport tranny. Synthetic fluids seem to help it out a little bit. When was the last time the fluid was changed or flushed?

 

NADIR_S,its not my situation but I am sure I'm speaking for a lot of folks here, If you can't help the man then why give such comment? The same effort you used to type that "uncalled for" comment you made, you could have helped him, appearently you wanted to know the info. also, otherwise you would have ignored the post in the first place!
If got something to say about it SAVE IT, I don't care about anything that don't hurt!

 

From experience, the only time a tranny increases in RPMs upon upshift is if it is slipping. You should get it checked out before anything gets worse.

 

The slight increase in RPM is because the ECU retards timing slightly to make the upshift smoother. Its completely normal and happens in all cars. Now, if your RPMs rise and stay there causing an extended lag for upshift (over 1 second), then that could be a slipping transmission.

 

It's pretty ironic that you wouldn't cut a newbie some slack and tell him to search when you yourself have posted 5 different threads about the bearing issue you have. How many times do you need to see the answer your looking for? You could always search for the last thread rather than posting a new one

http://forums.maxima.org/showthread....hreadid=166219
http://forums.maxima.org/showthread....hreadid=159661
http://forums.maxima.org/showthread....hreadid=159663
http://forums.maxima.org/showthread....hreadid=159759
http://forums.maxima.org/showthread....hreadid=160864

 

Sorry to have created such a stir...if I was more familiar with the forum, I certainly would have performed a search. Concerning all the well-meaning posts, I would like to thank you for your assistance. The vehicle has only 36k and has been doing this since new. It only happens occasionally, and under light throttle. The fluid has been changed several times since new, with synthetics, and the fluid level is correct. There are no leaks at all in the system. The vehicle comes off the powertrain warranty in the summer, and I would like to have it checked out (if necessary) before that time. i want to have my stuff in order, however, as my local dealer usually can't duplicate any problem i bring to them. Thanks again, and have a Merry Christmas...

 

The same thing has happened on my 97 GXE 80k for as long as I can remember. It only happens in the morning when the tranny is cold. When shifting from 1st to 2nd, the RPM's increase about 300 or so.

 

It's normal for 4th gen transmissions to have a slight delay and rise in rpms when more throttle is applied. I'm at 33k right now and mine has done the same thing since I've had it at 19k miles. I was originally concerned about it as you are but I've had the car checked out by a mechanic since then and it's seems normal from the posts I've read on the org. I've also been in a 3rd gen which has a slipping transmission and you can definitely tell when it's slipping because there's a huge unmistakeable delay. If your not sure then most likely the transmission is not slipping.

 

Thanks for all the good info...i really don't believe mine is slipping as the car doesn't seem to lose power...when this happens, the rpm's increase by a couple hundred, then it drops into the next gear...it has never happened in the lower gears; rather, at highway speeds, light throttle, when it's about to shift into OD. Perhaps the ECU is sensing it's not quite ready to drop into OD, under these conditions... ed