Hello!Just entered the community!I have a 2003 Maxima with an automatic gearbox, when the car shift from 1st to 2nd, 3th to4th, or shifts down gears, it basically shock the car a little bit, like it's a hard shifts, sometimes when the temp is low it doesn't do that infact it is much smoother, but after maybe 15 mins it starts to do that, I heard the lucas oil transmission fix does help the car shifts much smoother, but I'm a little bit affraid, the car has more than 300.000km, and I don't think my father did changed the trans oil ever before, does lucas trans oil help my tranny to shift smoother or I gonna blow my tranny?

 

Hi and welcome to the Maxima.org forums!

At 300KM the transmission has lived a long life and provided your Father with reliable transportation. I would check the fluid level first, than do a drain and fill even at this mileage to see if that improves the shifts. The shift solenoids might be clogged with contaminated fluid resulting in hard shifts. Make sure that there are no transmission related trouble codes stored in the ECU. A faulty dropping resistor will trigger a code and result in harsh shifts.

A used, working transmission is also an option if you want to keep the car. They are plentiful and affordable. Also, check oil level regularly and add as needed since those VQ35DE engines are known to burn oil.

 

Yes indeed, I do check the oil level regularly and it does burn oil very fast and I change them the engine oil in the correct time, the thing is that I checked the ECU of the car and there are no issues or faults about the transmission, I want to know if lucas transmission oil fix any good for my transmission? or does it help reduce those harsh shifts?

 

Some people call it snake oil and some swear by it. it will thicken the trans fluid. I used a bottle in my oil burning I35 and it did not make any noticeable difference.

 

Use the Lucas as indicated. Do not change the fluid if it's never been changed. Lucas is terrific in my experience and with my 2004 (also never changed before I purchased it). Add the whole standard size bottle even if you believe your transmission fluid level is full. It's okay. Lucas says the same thing but check before using it of course.

 

I checked the transmission oil level and it seems fine for most of the time, how to add the lucas bottle to the dipstick, does it need to be the car cold or warm? Is there are somethings to do during the process when you use it on your 2004?

 

I think your Ballast resistor maybe your issue and the temperature sensor on the transmission harness. I fixed this similar issue by replacing the transmission harness and solenoids with one off RockAuto. 240,000 miles 2003 Maxima SE.

 

Yes it might be the transmission harness, especially that my father didn't service it at least 15 years, do you have photos for the solenoids and the harness?

 

I might be able to muster up one...Why is a Photo necessary it's the only wiring inside the A/T. My Trans Oil temp sensor was apparently defective or intermittent but the car would not move when placed in drive when it was 1st start of the day. place the selector in 1st/2nd it drove by about 500ft. you could place it in Drive and it was good for the rest of the day. The temperature sensor was faulty and a new solenoid harness fixed the issue. These are available at RockAuto.

 

It sounds logical to be honest with you especially that I didn't check them at all, these might be the problem, does the transmission oil needs to come out to do the job and refill or not?