DaveO

I'm a G35 Sedan owner who's goal is to get my car's power as close to an auto trans 350Z as possible. Since the drive trains are essentially the same, I believe the goal is achievable.

Over the past week, I've reviewed numerous threads on this website and found many very well done and educational.

Considering the engine power upgrades planned for my G35 Sedan, I tried to gather automatic transmission (AT) information.

Conducted a search for G35/350Z AT information including basic maintenance and fluid level checks.

Found nothing on basic maintenance and fluid level checks. Did find many posts with thoughts, opinions and theorys. One said the G35's AT is the same as the 340HP M45's.
Was this a wish or factual? If true, what is the source?

Questions for discussion:

1 - How many of us do our own basic maintence including fluid level checks? (I do.)

2 - Does your owner's manual describe how to check the AT fluid level?

Mine says see your local, friendly Authorized Infiniti Dealer. (Inifiniti must think we all live next door, and have lots of time and money to devote to the dealer for routine fluid checks.)

3 - Where's the AT filler tube? Is it the one located between the back of the engine and the firewall?

4 - How does the dealer, or anyone else, check the AT fluid level?

5 - Has anyone looked into the stock transmission cooling system? Is it adequate for the increased HP on hot days?
(A real concern for us desert dwellers.)

6 - Has anyone had to replace their AT fluid? If so, was it due to normal maintenance, contaminated (burnt) or another cause.

7 - Considering Infiniti's AT fluid "threat" in the owner's manual, has anyone actually gone to synthetic AT fluid?

8 - Will it be possible to upgrade to synthetic AT fluid and maintain the factory warranty?

Grubbs Infiniti sells synthetic fluid on their website... do any Nissian dealers?

johnsZ

1) check the fluid when hot, idling in park
2) n/a
3) yes
4) idling, pull the dipstick (watch out for hot parts), wipe, insert, pull, read the oil line on the stick.
5) the fluid will normally be cooled to the engine water temperature- so should be OK. If you are worried, go to Summit racing, or Checker or Autozone and get a Hayden or B&M or Be Cool or similar cooling add on, install it in front of the radiator (I think the nylon through the radiator tie-wrap things are cheesy, but they actually do work and they do hold up for years...). You will have to do some cutting on the lines, use AN-X type fittings (Summit Racing) and dont spare the pipe clamps (you can get some nice covered ones with anodized aluminum covers colors are blue, red and polished). It is a messy job because fluid will leak out all over the place, but just wipe it up- it will not wreck the paint like brake fluid does. Then refill the A/T with the amount of fluid you think you lost- do not overfill. Then, warm it back up, check the fluid and add to top off at just over the middle of the fill marks.
6) no
7) no
8) seems to be a lot of discussion about warranty stuff. if the fluids you use are rated correctly (i.e., SE for oil), there should not be any issue- but don't hold me to this....
good luck

menehune

I tried searching for synthetic equivalents for nissan's AT fluid but I can't find any US vendors. Correct me if I'm wrong, but I think that Castrol has a synthetic, Castrol Transmax J, that is approved by Nissan. I don't know of any vendors though.

DaveO

Thanks John,

I appreciate your response to my questions.

Did your AT fluid check procedure come out of a 350Z owner's manual, or did you site the normal and usual way it's done on other cars?

This morning I removed the my AT filler tube cap (plug). There's nothing attached to the cap. So there's no way to check the fluid level without a "special tool. I did note however a sticker saying ONLY use Nissan type J fluid.

I guess there's a special tool required to check the AT fluid level... at least for the G35s. How about the 350Zs?

Boomer

My guess that the 5AT was derived from the Q45 seemed a safe one, given no other 5AT exists in the Nissan/Infiniti line as far as I know. If it were weakened somehow for the Z(which I doubt), it is capable of handling 340hp and 333ft lbs of torque in the Q and M45. Mine seems to be very robust, in full auto or manual mode. Your other questions have been answered by others.

I just checked the maintenance schedule and it becomes an option under the premium service schedule to change the trans fluid at 30,000 miles, see #7. All of the next premium service intervals, it remains an option through 120,000 miles, unless conditions are harsh! I will be changing the fluid in my 5AT Z every 30,000 miles because I use the manual mode more than the full auto under all conditions except limited access 4 lanes and Interstate highways. I would suggest you do the same to offset any added strain on the trans, if you modify your G35 5AT to the 350Z HP levels. Given the fluid change is an option only under harsh conditions, I think we should be covered for most situations.

Boomer--my advice, use it or lose, I don't care.

johnsZ

If you are changing over to synthetic trans fluid- then you should have the torque converter pulled and drained, as well as pulling the pan and filter.
Unless the fluids are compatible you could have a real mess and possibly gum things up...I do not know how the fluid replacement process will work with changing from standard to synthetic oil. But it will probably be over $200 since they will use 14-16 quarts of synthetic oil in the transfer process.

I would talk to a trans guy first.

The engine oil can be changed to synthetic because you can get almost all of the oil out with a new filter and a careful draining of the oil pan. By the second oil change, the synthetic stuff will have taken up the old oil and the changes will have dumped the old residues.

johnsZ

On the fluid check- I just called out the method I normally use. BUT- I did actually check just now- there is no dipstick, only the breather held on by a hex bolt. Kind of interesting approach- owners cannot conveniently monitor their own fluids. So off to buy one.

The engine oil stick is a real twisted mess- I check that on the first day I had it. Maybe LOKAR will build one with a chrome head.

jeffa

The 5AT is a sealed transmission, hence the absence of a dipstick...

Boomer

Uh, maybe I will be replacing the AT fluid at 60,000 miles. $200 per fluid change is pricey. Oh well, I probably won't be at 30,000 miles for 4 yrs being retired and having 2 cars. It may be worth it for you in desert conditions. Check your manual, it should have a caveat for harsh conditions like mine does.

DaveO

Sent AT dipstick pictures to my Infiniti dealer... reply below.

"Infiniti does not consider the transmission as consumer serviceable."

"According to our Master tech, it appears the picture you have sent is a modified dipstick plug, not available through Infiniti; however, it probably could be manufactured. The tool we use to check the trans fluid level is a big t-handle and is not a part that you can leave in a car. If you have any questions, please call. If you can come up with a part #, let us know."

More data needed. Please check to see if you have a AT Dipstick or a plug.