Hello,

I just got myself a 5th gen Maxima 3.0 with 4 speed automatic. I especially looked for Maxima with 4 speed AT because what I've understood, this gearbox is far more reliable than the Aisin made 5 AT box. Is this correct? Did Nissan improve the 5 AT at some point? At least the 4 speed box seems to operate flawlessly in my car.

 

My 4speed started to fail at 85k, and completely let go on the freeway at 90k.
It was rebuilt and still slips shifting from 2-3 when cold. I've always kept clean fluid in it too.

 

Yes, very reliable. Flush all the fluid out cooler hose and use synthetic whatever.
Worst case you need to replace VB or solenoids.

 

ukmastermind, sorry to hear that. What caused the breakdown?

I only have good experiences of Jatco's old 4 speed boxes. We used to have an old Nissan Primera P10 (year model 1991) with 4 speed Jatco box and it lasted over 420000 kms. Everything else begun to fall apart (the car was over 20 years old then) but the transmission just kept going.

The 5AT box is a bit different story. The Aisin AW55-50 was used widely in many car models, and I had two Volvos with that box. With both cars, the Aisin box gave up and the culprit was the valve body. It also was quite jerky at times, especially with the 2-3 shift.

 

During the teardown, they found worn out clutch discs, failed brake band and cracked gear set (i think..been a while). Before the failure, I had the shop replace the valve body, which seemed to help a little until the tranny let go one night. Probably just my luck. I've kept clean fluid in it since the rebuild and it's done well except for the slight 2-3 slip when cold.

The 4spd in my 95 Max SE was phenomenal. Fast firm shifts and not an issue in 200k+ miles. Wish I had that tranny in this 03.

Just keep your fluid clean and you're good to go!

 

I have a 2000 with that 4 speed in it. I currently have 280k and almost no issues. I did a drain and fill at 210k and another at about 255K. Only issue is when it's below 50 degrees on a cold start it takes about 10 seconds to go into drive. It's been doing it for like 3 years so I guess it's ok lol. I'm surprised that this thing has lasted this long. This car has been daily driven in DC area traffic for almost it's whole life. And it's hot here in the summer so I know it gets super hot sitting in stop and go traffic on the beltway with the road temps above 100.

 

The 4-speed auto is still better than the modern CVTs. Installing an auxiliary tranny cooler along with fluid changes should help to prolong its life. Some owners are getting 300K on the original transmission.

 

Yeah, that's just solenoid with cold bug. You could swap it out for next to nothing, but if it works, **** it.