Transmission shifts hard

Hello,

The first thing is to check the transmission fluid level. If okay I would change out the input shaft sensor. here is how in the diagrams below:

Fluid Types
Recommended fluid .................... Nissan Matic "K"

NOTE:Using Automatic Transmission fluid other than Genuine Nissan Matic K ATF will cause deterioration in driveability and automatic transmission durability, and may damage the automatic transmission, which is not covered by the NISSAN new vehicle limited warranty.
Capacities

Fluid Capacity .................... 7.3 L (7 3/4 US qt. 6 3/8 Imp qt)

Check out the diagrams (below). Please let us know what happens.

When in slow traffric the transmission often will not shift out of first until you park it and let it sit for a while then it will most likely shift. Transmission has been completely rebuilt and the transmission shop says its the catalyic converter locking it into first gear at times. It may run well for a number of days and do it again. Whats up.
Dan

What codes are in the computer. I would expect the CEL to come on with this and have a po420 code. IF the converter is plugged it can be from a piece that has turned into a position that does not allow flow. You can rap on the converter and listen for broken pieces rattling around if this is happening. This is a piece from a converter we replaced.

IT is a honeycomb like configuration. IF a piece flips there is too much backpressure.

Please address the relationship between the codes and transimission and the backpressure. The car will move in first gear at a high rate of RPM's
What are the CEL and po420 codes to a layman and will these prevent the trransmission from changing out of first gear? I will have the codes checked aslo.
Thanbks, Dan

Your response below:

"What codes are in the computer. I would expect the CEL to come on with this and have a po420 code.
IF the converter is plugged it can be from a piece that has turned into a position that does not allow flow. You can rap on the converter and listen for broken pieces rattling around if this is happening. "

PO420 is the code for a bad cat typically, but there may be transmission codes or others.

Most of the time a plugged cat acts like a governor and limits the engine RPM to a fast idle. Combustion must have a release which is the exhaust. If the engine can not gain momentum because it can not exhaust, the transmission will have no reason to shift.

There are two ways that you may be able to check this besides what I already mentioned. Remove the front oxygen sensor so there is less restriction or better yet disconnect and support the front pipe. Therefore no restriction. If it runs good at that point you verified the cat....or plugged exhaust of somesort.

Thank you very much. My daughter has since found some diagnostic paperwork The code is po420 low bank one and calls to rplacing the "y" pipe (Cat I guess) Your information certainly confirms the likely problem and thanks for the help.
Smiles!

My pleasure, good luck.

I have had my transmission flushed and serviced. My shifting is completely okay when driving normally. But, when I am starting off and give a lot of gas, I feel a hard shift from 1st to 2nd gear. Then at about 3500 rpm's, I feel an obvious hesitation and it begins to act like it's not getting a smooth flow of fuel. My speed is not increasing like it should for the amount of rpm's I am seeing. I guess what I'm saying is that it is not running like it did a year ago. It has about 102,000 miles on it and has been taken very good care of. It has never leaked anything and has had routine preventative maintenance done like it should. My regular mechanic said to take it to a transmission shop and have the control valve assembly replaced. What do you think?

Check engine light On?

I would have the throttle position and vehicle speed sensors scanned and see what they doing before you get to the tranny. Probably a shift solenoid problem connected to the valve body control valve.

jds7345,

I am having what seems to be the exact same problem you are having with my nissan maxima. Have you been able to get the problem fixed yet? If so, I would like to know what the final diagnosis was, if you wouldn't mind sharing. I'd like to be able to tell my mechanic when I talk to him about having it fixed. Any information you can give me would be greatly appreciated. Thanks!

[quote:8db0339c3c="rasmataz"]Check engine light On?

I would have the throttle position and vehicle speed sensors scanned and see what they doing before you get to the tranny. Probably a shift solenoid problem connected to the valve body control valve.[/quote:8db0339c3c]



The check engine light comes on and goes off with no real pattern to it. It may stay on for days or a few minutes.

[quote:1951141318="schutza"][quote:1951141318="rasmataz"]Check engine light On?

I would have the throttle position and vehicle speed sensors scanned and see what they doing before you get to the tranny. Probably a shift solenoid problem connected to the valve body control valve.[/quote:1951141318]



The check engine light comes on and goes off with no real pattern to it. It may stay on for days or a few minutes.[/quote:1951141318]

Try to have the OBD2 code/s pull and comeback with it.

I have a Nissan Maxima with 185000 miles.. The car runs great but it's been a few weeks since it started to shift hard. From experiences with other cars I do not believe is the transmission because it started all of a sudden not gradually as usual and this was confirmed by few mechanics. However, few have said that the problem is with the transmission selenoids and say they have to be changed. Another version given by a transmission mechanic was that it is nothing related to the transmission and that it is an electronic problem created by the remote starter that was put by a car electrician. The transmission mechanic said that supposedly a cable was damaged or altered when the starter was inserted so this makes the computer send bad signals and thats why the car shifts hard. I don't know what to do or who to believe so I need help, any opinion would be greatly appreciated thank you.

how long ago was the remote starter put in?

Thanks for your reply... The starter was put 1 year ago

thats strange, I would listen to the tranny guy. if this is a repair shop where this guy is from and he told you this at his place of business, then I would go with him, usually they will say anything to make some money even though its not necessary to do whatever it is that they recommend. but he is not trying to do that . he's saying that it has something to do with the remote starter. I would start by bringing it to the place that installed it and take it from there