I also came to the same conclusion that the ambiguity on maintaining the 7AT was no accident. Unfortunately my problems with that trans did not end there with that first replacement, however the remedy I sought ought was all related to maintaining the trans fluid. First I just changed it out more frequently (every 10-15k) since I was using the car in a "heavy duty" sort of manner. Secondly, I added a transmission oil cooler core.

One thing id watch out for is the fluid that the dealer fills your new trans with. Make sure they use Matic-S and not Matic-J, there was a training issue here in SoCal where the techs mistakenly thought that the 370z could use matic-j because they thought it was interchangeable. The truth is it isn't, that fluid is designed for the automatic in the 350z and does not have the necessary friction modifiers for the 370z. If they put that fluid instead of matic-s in your car, you will legitimately have another warranty issue on your hands. There is even a TSB out there that describes this very issue but somehow, it gets misunderstood by the dealers.

As a 7AT owner I can't wait to hear the outcome.

I full flushed per JCHammond's directions at 72k when I got the car. 10k later I dumped the pan and the fluid was still red so I simply refilled. I'll go in 15k later and see what it looks like on a pan dump next time. I have a Hayden trans. cooler sitting in holding pattern for when my front bumper cover comes off for headlight mods. I'm also working with an ECUtek tuner firming up shifts so as to save the friction plates. The car is only street driven but sometimes spiritedly.

Yeah still rolling in the loaner 2019 Sentra... basically you have to plan an 1/8th of a mile ahead if you want to be in a certain lane at a certain time, because there really is NO power. I mean, none. A prius is faster. It beats walking and it's strangely calming to drive, but made me realize one thing: 99.9% of the cars/vehicles on the road are boring and just "fit in" and now I'm one of them! I just don't see Nissan lasting much longer selling cars like the Sentra...

So apparently they had to order a transmission from NY and have it shipped here, "2-3 weeks" So I think it's been about 2 weeks, so perhaps I'll get the car back this coming week...

My latest theory:

1) Transmission fluid wasn't changed til 40k miles, and either that was simply too late and damage was done up until that point (and yes, I asked starting around 20k miles, and got the "it's a sealed transmission/100k miles speech), or
2) The wrong fluid/under/over fill occurred when it was done
3) Bad luck...

I think a Stillen Transmission cooler will be ordered once I get the car back and if everything seems fine. I'll only have 12months/12k mile warranty on the new transmission, then, I'm on my own with the thing.

In the big picture: If this doesn't work, or it breaks again, I'll just have a transmission built as that's still going to be cheaper than starting over with a newer car and going into debt (Short of a new job that pays more, then I'd keep it and get a lexus product as a daily/shoulda kept my sc300).

Is this the one to buy?

https://www.stillen.com/performance/...ooler-kit.html

(something tells me that the only reason it didn't come stock with the car was: a) cost savings b) risk/reliability with running additional lines c) Nissan doesn't adequately stress test vehicles before putting out into the market (the cvt lawsuits are a perfect example).

Not sure I bought the Hayden unit Z1 sells on their site for $79 on ebay for $29 shipped. Says for vehicles 10k GVWR and under.

I believe the Z's have a trans cooler built into the radiator but it probably doesn't keep the fluid cool enough during spirited driving.

There is a trans cooler inside the radiator, and barely holds up to daily driving. That's why the recommendation to put an external cooler on (heat is the killer for ALL A/Ts, not just ours). I've had best luck with A/Ts when changing fluid & filter at 10k or annually, depending on how it's driven. Yeah, it's a pain in the tuckus, especially on the ones with no drain plug. :eekdance:

in short:
1) external trans cooler
2) regular fluid changes with a quality fluid
3) don't buy the dealer BS about 'sealed' transmissions... they don't exist. :bowrofl:

It's amazing that I've seen SC'd Z's without any trans. mods including a cooler and the owner thinks all is well!! And as far as #3 goes my '13 F150 V6 company truck has a trans. whose 1st service doesn't come until 150k miles haha. So far six years and 120k on the original fluid. Glad I don't foot the fill on it!! :shakes head:

Okay so received word that my car will likely / "may" be done in the next day or so.

***** HELP needed please *****

Should I buy this:

https://www.z1motorsports.com/coolin...37-p-4891.html

My thought process is that by eliminating the stock radiator at this point would reduce the chance of any contamination, and the unit "sounds" like it has additional cooling capacity compared to the stock setup, that would either directly or indirectly help with the AT temps, while being a simple plug n play stock replacement.

So would you people suggest I get that, and/or, the stillen external cooler here:

https://www.stillen.com/performance/...ssan-370z.html

Should I get one or the other or both?

It seems with the stillen external kit, there's some issue around the fitting sizes not being correct, thus requiring additional parts to make it work without the risk of leaks (the plan is to have the dealer install it so... yeah...), outlined here:

http://www.the370z.com/engine-drivet...installed.html

I owe everyone on here a thank you for being helpful, def a better forum experience than others I've belonged to in the past!

The dealer should flush the lines and the AT radiator before installing the new trans. Personally, I'd go with an external cooler, rather than replacing the entire radiator/condenser assembly. Replacing the radiator/condenser means evacuating and recharging the AC system, something else to suck up $$. I think the reason some people had a challenge with Stillen's trans cooler is that they didn't go far enough back on the hard lines before clamping the hoses. The coolers that I've installed have used a similar setup, but I cut the hard lines to remove the ends, double clamped the hose to hardline and never had a leak. I'm going to presume that the hard lines on our car threads into the radiator, so the other option is to find an adapter that threads on the connector to the hard line, then connects with the rest of the Stillen system.

Thank you for the response! I'll get the Stillen and advise them of what you've stated above.

Got the car back...

Shifts buttery smooth, didn't really have a chance for any full throttle runs due to weather/traffic...

Invoice shows the following:

JA01AA R&I Automatic Transmission ***'y
3460 WP
4 21626-32U00 Washer-Seal
3 31009-21X00 Bolt-Self Lock Converter
1 999MP-AM006P Transmission Cooler Flush
8 999MP-MAT00S Matic-S ATF - 1 QT x 12
2 20692-JK00B Gasket - Exhaust
2 20692-8H30A Gasket - Exhaust
4 20602-41G00 Nut - Front Exhaust Tube
2 08918 - 3401A Nut - Flange
1 310CM-X767BRE Reman Transmission Assy-Autom

Notes appear from Tech:

"Confirmed that the vehicle felt like it was going to stall when normally driving. Removed transmission pan and inspected for debris. Found Large Chunks of Metal in pan. Replaced transmission assembly. Flushed Transmission cooler lines and transmission cooler. Replaced exhaust gaskets and propeller shaft nuts/bolts. Set transmission fluid level and test drove vehicle. Confirmed normal operation."

The one I signed showed just over $6,000...luckily my cost was $0 :driving:

Things to note: Stock fluid from 0-40k miles, then it was changed + some software update. Shifts were noticeably firmer, but around 4-6k miles after fluid was changed, I noticed 1st-2nd shifts seemed to be noticeably firmer compared to other shifts, especially when cold. 55k miles is when this mess occurred with the stalling issue.

What I'm lost on: I see TONS Of videos on youtube, people racing, running the living snot out of these, so I either am a bad driver, or just bad luck or both...

Happy to have it back, it was immediately treated with a jl audio sub upgrade (10w0 to now 10w3's).

:eek::eek:

Trans cooler and regular service will save ALL A/Ts. I'm glad you had a $0 out of pocket, R&I transmissions is never cheap.

Yeah so in looking at transmission coolers... SHOCKING that there's a cooler available for most nissan models. AKA: Nissans should have come with these and oil coolers from the start, but... Nissan is cheap. They should atleast offer them as an option on the sport/nismo models.

As far as I can tell my '10 has a trans cooler integrated into the radiator as there are trans. fluid lines going from the trans. to the radiator on the driver's side. I guess it is not stout enough to handle aggressive driving. I'm not big on trying to cool anything with engine coolant anyway.

Yesterday I added an air/fluid in it's place rated at 10k GVWR.

All A/Ts come with the cooler integrated with the radiator. It's not very efficient (hot liquid into hot liquid...:icon14: there is some temperature delta 190/230, but you are putting 190* liquid back into the trans)

Exactly why i replaced with an air/fluid cooler yesterday. :tup: