Transmission harsh shifting or shift shock?

This is common when the countershaft sensor starts to go out but, we should check the fluid level and condition in case the transmission needs to be serviced. Also, is there a check engine light on? If so, please go over this guide to get the codes.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Here is a generic guide to help you step by step with instructions in the diagrams below to show you how on your car.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Note: Use a 3/8 drive ratchet for the drain plug.

3. Remove the drain plug and drain the automatic transmission fluid (ATF).

NOTE: If a cooler flusher is to be used, refer to ATF Cooler Flushing.

4. Reinstall the drain plug with a new sealing washer.
5. Refill transmission with the recommended fluid into dipstick hole to the upper mark on the dipstick. Always use Honda ATF DW-1 (ATF-Z1 has been replaced with ATF DW-1, Honda Service News Nov 2010) Automatic Transmission Fluid (ATF). Using a non-Honda ATF can affect shift quality.

Automatic Transmission Fluid Capacity:
2.7 L (2.9 US qt) at changing
6.0 L (6.3 US qt) at overhaul

Check out the images (below). Please upload pictures or videos in your response to the problem so we can see what's going on.

Oil is changed 2 years ago, 3 liters only and had run only around 10,000 km since then. The condition of oil now is still good by looking at its color. Oil level is good also.

No check engine light,
I noticed that the sensor near the dipstick is wet with oil up to the connector. (I think this is the countershaft sensor), problem still exist after cleaning it.

I also cleaned the linear shift sensor, number 10 in the diagram attached.

Can the shift solenoid be also the reason? Number 8 in the diagram. Also, can I pull it out just by removing the battery and other wires above it?

Usually there will be a trouble code for the shift solenoid, but I would test the shift solenoids with a voltmeter to see if one has much lower resistance than the other, they should be about the same.

Here is a guide to help:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

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

I will try to do resistance test since there is no trouble code during scan. Maybe a little cleaning will help. Can i pull the shift solenoid by just lifting the hood and taking out the battery and the battery holder?

I believe so, remove anything in the way of doing the job, if you are not sure upload an image so I can help walk you through the repair.

Thank you so much. I will try to pull it out on my free time.

You are welcome please let me know how it goes.

Hi. After cleaning the shift solenoids and do a transmission oil change, the problem is still present. Shop suggested that the transmission be pulled down and do filter change and valve body cleaning, which is a little tedious and costly.

Did you replace the counter shaft speed sensor? This is a problem with these cars, are is the location.

Not yet, just cleaned the shaft speed sensor since there is no check engine light on.

Yep, the sensor can still be bad, I would swap it out anyway. If the sensor becomes weak it will give false readings but not enough to trigger a check engine light.

Would you mind sharing the part number of the shaft speed sensor?
Thanks

Is this the sensor?
Thanks

Yep, that looks like it. This should be the part #

Denshi
1 - Speed Sensor - 78410S04972

This one is the VSS?
Denshi
1 - Speed Sensor - 78410S04972

I'll have them checked too

And.., my fuel usage is now only at 5.5km/liter. Too bad

Yep, that is understandable, let me know what happens with the sensor.