2006 G35 AWD
What is the best transmission fluid to use and where to get it from? I made the dealership flush my trans fluid and they used 134 ATF Dextron 3 MERC. I dont know if this is good or bad or an equivalent to Matic J ATF*4. Can you please help?

 

What dealership, couldn't have been the Nissan or Infiniti dealership because they would only use Matic J or S.

 

It is actually the Infiniti dealership and when I asked about the reason why they didnt use the Matic, they told me that they use that brand on ALL the infinitis that need a trans flush. They also argued that this is certified by infiniti, which is weird becasue the owners manual indicate that this should be Matic J ATF*4.

 

Get it in writing exactly what they used and that they were authorized to use that fluid in case you develop transmission problems. There's a really good chance it will work fine however it's NOT an approved fluid so I'd keep proof that they used it so you can make them give you a free transmission or repair the one you have if you start to exhibit problems.

I would also call Infiniti customer service and ask them directly, report the dealership that you went to and ask them to investigate this issue and report back to you, have them create a trouble ticket so there's also documented proof with Infiniti corporate.

 

Dishonest service managers do exist and this is throwing up a big red flag for me which is why I suggest you take the steps to cover your *** because transmissions aren't exactly cheap and these ones are prone to problems from using anything other than matic J/S.

 

Totally agree with Cleric. That's bizarre from a dealer and you are right to question. Based on what I've read here, a flush at the advanced age of your tranny is also ill-advised. Drain and fill seems to be the better option.

 

I only have the invoice with a description of the service and the materials used. Should I buy the Matic S or J online and make them reperform, or maybe just take it somewhere else to perform the service? The reason for this is that I am going to change the passenger's side axel and while doing that there might be some trans fluid leaking and I dont want to fill it back with the brand that the dealer used. So I am willing to buy the correct brand online and get the mechanic to do the drain and refill once the axel work is done.

 

You won't lose fluid changing a driveaxle so that's not really an issue. How many quarts of fluid did they use, I suspect what you got was a drain/fill which swaps out about 4 quarts of fluid because power flushing is specifically NOT recommended in the factory service manual. If you just had a drain/fill... well there's a lot of variables to consider, if you have high miles in the area of 150k or more I would leave it, your transmission will likely last the remaining 50k or so before there is significant wear on the clutch packs and a rebuild would be imminent anyways so any damage to the valve body is likely to happen at about the same time that a rebuild would be needed anyways.

However if you are closer to say 100k then the transmission still has half it's life left, in that case if it were ME I'd probably do TWO drain/fills (d/f then go for a little drive, come back and do another d/f which would reduce the foreign ATF levels to roughly 12% of the total volume of the fluid which shouldn't be enough to damage anything, any further fluid drain/fills will reduce that % by even further.

If it was a full powerflush complete transmission fluid exchange then I would leave it and as soon as the tranny ghosts take it back and demand another one and throw your written proof and the Infiniti corporate ticket # that you opened back at them.

Here's a snippet directly from the Infiniti Factory Service Manual.

 

Matic S supersedes Matic J now so most dealerships just use Matic S which is perfectly fine.

 

I bought an '05 G35x and did three drain and fills with Redline D6 ATF. I could tell right away how much smoother the shifting was.

Funny thing is, my dipstick does not read the correct amount. No matter how long I let the car sit, when I pull the dipstick out it shows the fluid level inches above the top mark and I know it isn't over filled. Even after sitting for three weeks, I pull the dipstick out and the tranny fluid is covered far up the metal.

Last time I did a drain and fill I put 4 quarts back in and called it a day. I need to find a G in a wrecker yard and take its dipstick, just so I can be sure in the future that my level is at the proper level.

 

Redline D4 or D6 seems to work with everything. Honda used to specify their Z1 ATF for use in their automatics. The problem was it had so many friction modifiers in it to soften the shifts (soft shifts mean slippage and wear) and was especially problematic for the V6 automatics, which were notorious for going out before 50k miles. Part of the problem was lubrication of the 2/3 clutch packs but part of it was the fluid. They changed the OEM recommendation to their newer DW1 ATF which has less friction modifiers. They no longer even sell the Z1 stuff. Transmissions now have a firmer shift but they also take longer to wear out. Switching to DW1 made a big improvement in proper shift feel, Redline D4 even more so. My Accord now shifts like it should, fast and with a firm, distinct shift feel. But its not GM shift kit tire chirping harsh by any means.

The main reasons OEMs specify their fluid is because of the specific shift quality they want. And typically, that is more for the soft, smooth shift Joe Average wants. People change to a non-OEM fluid and then complain about "harsh" shifting when it reality, that's how a transmission should shift, quickly and firmly.

 

There's a lot of math behind the scenes for it too depending on what line pressure it operates at and the speed in milliseconds that it takes for the solenoids to engage/disengage. The fluid is matched to the parts they sourced.

I'm not sure I understand exactly what you're saying but it sounds to me like you are checking your transmission fluid cold and with the vehicle not running which is wrong. You always check fluid on a hot transmission, go for a drive, make sure it cycles each gear, when you get back run the transmission manually through each gear including a full reverse engagement so fluid takeup is at it's MAX and the fluided has expanded to is MAXIMUM volume. Then leave the vehicle in park while you pull the dipstick and check it half a dozen (or more) times, wiping each time, until you get a clean reading.

 

In my '06 I have a cold level and a warm level check. Pretty smart of Infiniti.

 

Yes and no, its more to match everything to the shift characteristics they want. Back in the olden days you could literally pour in a "shift kit" by using B&M Trick Shift ATF. It was basically a tweaked Ford ATF version without any friction modifiers. Perfectly safe in the GM transmissions of the time and it would make shifts much, much firmer. But that's not what the average Cadillac or Buick driver wanted. So GM spec'd an ATF that gave smoother shifts, albeit at the expense of transmission life.

Now the newer automatics have pretty much made this a moot point, they shift much quicker now regardless of the ATF. Faster shifts help mileage, probably not a huge amount but combined with the start/stop at lights, extra gears, etc it all adds up.

 

FSM reads how to change ALL fluids. Transmission is done warmed up. Valvoline Max Life synthetic is what I use.