I’m at 71k miles and have had a “fluid exchange” requiring 12 quarts of Matic-S done twice at the dealer.

My understanding is that they use a special vacuum pump attached to the supply and return lines (pulling old and supplying new fluid)which go to and from the transmission cooler inside the radiator while monitoring fluid temperature with a CONSULT-III as the the proper fill level for the 7AT transmission fluid is based on the volume of fluid at a specific temperature. They use more fluid than the transmission holds to ensure that all of the fluid is replaced. This is also why the service cost more than a simple drain and fill which requires just 5-6 quarts.

 

So embarrassing.My bad

 

My understanding it that it's ok to use a fluid exchange machine that hooks up to the cooler lines and just puts in the same amount of fresh fluid vs the old fluid that comes out. What's "bad" is using flush chemicals. That's what the guy told me when i had mine done. He said he's seen a few get "messed up" after a flush and so has Scotty Kilmer. And they say lifetime but mine shifted so much better afterwards after I had mine done at 70 thousand miles. I would get this hard banging, like hitting a pothole, at low speeds in stop and go traffic and harsh shifts that went away with the new fuid. I think as the Nissan fluid ages it just can't handle high temps anymore.

 

Scotty Kilmer...

The OP only has 9 comments on the forum and he's already more trustworthy than that drunken hack.

 

Not sure what I think of Kilmer, but his style is often entertaining (borderline annoying), but much of what he spews is somewhat basic and very subjective for most enthusiasts, reminding me of Quora discussions on similar topics (most popular ones "Should I really change my oil at x number of miles or should I extend the interval to what the oil manufacture publishes on the bottle?" or "Does the transmission really need to be serviced, or is the dealer trying to rip me off").

He tends to use the same brush to paint many of the topics he covers; Definitely helps sell alot more used Toyotas and Lexus (good cars, but not the only good ones).

I tend to prefer the no emotion, lots of charts approach of this guy better:

https://www.youtube.com/user/engineeringexplained

Regarding the "Flush", the Infiniti dealer uses a cleaner and lubricant during the fluid exchange process. If I decoded the invoices correctly, it's this product from MOC: https://mocproducts.com/products/pre...tf-supplement/

"A concentrated conditioner designed to fortify and extend the service life of ATF. This blend of synthetic base oils and additives improves fluid oxidation stability, conditions seals to prevent leaks, slows sludge and varnish formation, and helps control transmission shudder."

My thinking is that the manufacture of the transmission fluid exchange hardware has likely tested and includes the use of a conditioner like this as part of the fluid exchange process that has been tested, certified and warrantied.

MOC has been around since the 1950s and has provided products of this nature to consumers and more specifically automotive manufactures for decades. I recall reading on I believe the 370Z community, a Nissan Tech said that MOC also extends a warranty related to the use of the product to their dealership partners.

Can additive like this cause harm to a fully functional transmission if not used correctly? Maybe, as anything is possible and I for one have never been a fan of dumping chemicals into a car without understanding the tradeoffs (recall "Slick 50"?). Are the naysayers like Kilmer correct, and there is a master plot to destroy automatic transmissions via the use of additives just to make $15 off each bottle and ultimately sell a brand-new transmission, with no regard for reputation and integrity?

Call me niave, but this doesn't seem logical.

 

My stand point on flushes is that many folks who get them done dont truly understand what they want or are coerced into it. I would say about 60% of the people who get "flushes" done really just wanted the fluid changed.
I would compare an automatic transmission flush to an engine flush. Most of you know that an engine flush can have very little effect on the cleaning aspect of the engine and what will do is ensure ALL of the oil is replaced. Something you cannot do on a drain and fill. The issue here is that there are far more was to create damage in a flush than in a drain and fill. I've noticed that cooler line pressure for the 7at is not the same as internal pressure so it would be very simple to make a mistake in the pressure the machine sends back into the transmission by either sending too much pressure back into the transmission or barely any. You removed this worry by drain and fills like you would do with an engine oil change.
The hardest part of it with this 7at is max fluid measurement because of a lack of dipstick but in all honesty, proper research can inform folks better and restore the confidence.

 

They way they did mine was to just wait until the car cooled off then they did the exchange. Then they cut the car off then they pushed a button on the machine that put fresh fluid in until it came out of the overflow hole.

 

Either should be fine in a healthy transmission and as long as it's done correctly. My preference and if it was my vehicle would be to keep on top of maintenance and do a simple drain and fill every 24K

 

IMO, there's no need to have to get that complex with doing a flush, but whatever works.

 

FWIW, I recommend any good brand of Dexron VI in these transmissions for anything that we do.

 

Hello,

New to the community. I am so happy to have found this site and you.

I have a 2012 G37x about 125k, and I drive in New England. My alternator failed (battery and brake light on together) and I decided to tackle the job myself, I never had any transmission issues. It took me a while but I replaced the alternator and serpentine belt. Put everything back together and started the car, no issues

When I was under the car putting the radiator fans back together, I noticed two pretty rusty hose clamps on the drivers side of the car connecting two rubber hoses coming from the radiator to two metal pipes, maybe 3/8 diameter. I decided to add stainless hose clamps (screw them to tighten), inside of of the factory clamp towards the metal pipe the hoses connect to. I did not remove the hoses and left the factory clamp in place because I was not sure if these lines were under pressure. I was able to replace one as it is a PITA to get those stainless screw clamps back together once they are undone. I could not get the other in place and I decided to save the job for another time as I was in a rush to meet my wife to pick her up after a trip.

Decided to test the car, seemed to do ok, then I noticed the transmission slipping which had never happened. It kept getting worse and I was losing power, and it was not shifting gears. I tried putting it into manual mode but it did not matter. Barely made it to meet my wife, I left the car at her work parking lot. I was thinking the issue was having the battery disconnected for 24 hours and I might need a reset of something or other. I did not want to drive the car and ended up getting a ride home and when we pulled into our driveway, it was covered with oil. There was a line of oil visible from when I backed out of the driveway, stopped, and then drove off.

All I can think is one of the hoses let go and I lost all the transmission fluid. There was no burning smell, I did turn it off the car and restart the car and an AT light light up briefly but shot off. Does the car have a limp mode or did I destroy the transmission? Where do I go from here?

Thanks in advance,

Wolfy,,,,