Well after driving my car about 40 miles the trans seems to be back to normal. It only grinds when cold and shifting fast. After 3 minutes of driving its perfectly fine. It shifts smoother as well.

 

if you can live with that compromise then that's fine. however your nearly brand new car shouldn't grind at all. nissan MTF is best in our case. you won't regret it.
https://www.mynismo.com/products/?id=3920

 

wouldn't that be up-shifting?

 

hmm this is kind of interesting, debating if i should stick with the motul gear 300 that i already have or purchase the OEM MT fluid?

 

OEM stuff is back in, and the tranny actually is shifting better now. Go figure.

 

when i was searching gear oil i haven't found too many replies about gear 300. maybe one bad reply? i've found bad responses for almost every other type of gear oil however. all my drifting friends swear by straight MT-90 and it ended up being bad on my G35 trans. works great in the S13 though. so it's definately a coin toss. however, if you don't have a problem with oem then stick with it. in this case, if it ain't broke, don't fix it. if you're doing your own changes then you might be underneath the car a second time.

also, your cars are still pretty new, why change so early? good luck. maybe someone will find an aftermarket oil that works without any compromise. please post results.

 

I put redline GL-4 in, can't remember if it was one weight or a mix (for some reason I think it was 2 quarts of one and 2 quarts of another), and within 500 miles my tranny had thrown a synchro. My lesson was to not change the fluid until after 30k miles, regardless of what the manual says. I don't know what caused it, and I have trouble believing its fluid, but reading this makes me feel otherwise.

Edit, in response to below and thanks for jogging my memory, I mixed 2 quarts Redline MTL (GL-4) and 2 quarts MT-90 (GL-4) to get roughly a 72.5W85, this proved not a safe mixture it appears (although others have posted success with earlier year Z's)

 

OEM MTF is a 75W-85. Kinda odd viscosity that can't normally be found in most autoparts store (mostly 75W-90).

I still with OEM MTF for the transmission, but for the differential, Royal Purple MaxGear 75W-90 works wonders

 

i'm in new jersey. i had RP maxgear 75w-90 in the oem vlsd. when the temp was below 30 deg it would howl for a couple of minutes until the fluid got up to temp. so i switched to convention castrol hypoy c 80w-90 and the problem hasn't returned (knocks on wood). someone should make a sticky about the different gear oils and the results people have been getting. i would not want anyone going through what i went through with driveability problems and having to climb back underneath the car in the dead of winter.

 

I'm in Southern California so 30 below has have been an issue for me. RP Maxgear seems to be on the higher(thicker) end of the 75W-90 viscosity spectrum.

 

changed the transmission fluid to a mixture of redline mtl and mt-90 gl-4......results so far are smoother shifts and fast shifts from 2nd to 3rd dont feel spongy anymore, just nice and solid. no grinds.

 

don't be afraid of transmission fluid.

 

yea you dudes in ca should be able to get away with redline mtl/mt90 or straight mt90 simply for the fact that the climate is warm. i didn't start noticing the bad shifts until the temp drops into the 30s. yay for me.

 

I'll post this assuming the answer is yes, this is on a 2007 or 2008 correct?

My transmission failure may have been unrelated (and I had deemed it so), but I still figured I'd play it safe since the manual very oddly stated to use only Nissan fluid unless it was unavailable (seemed odd, the wording was almost implying there was a difference between nissan fluid and other brands in quality) so I decided I'd just give up on the redline stuff for future changes.

That said, I find it odd because tranmission fluid isn't where you make money on a maintenance item, you sell a $2 a quart oil for $3 a quart and make up some approval process its a pain to go through for your warranty to be valid saying you must use Nissan ABC approved oil. Pick random cheap oil, approve it, stamp it with a Nissan logo and charge more for it.

Makes me think there might be some additive in the transmission fluid, possibly even added after the early Z's to help reduce with the synchronizer failures.

 

^ yep, 08. im not really worried though....i put the right stuff in there so if anytihng goes wrong i have warranty. i dont see how a synchro could blow just from using non nissan fluids .....

 

maybe because you pull the shifter "down" from 5th to 6th?

jim

 

I'm more cautious having JWT bits connecting the engine and transmission. But I am thinking there might be some additive in the Nissan fluid we aren't getting elseware.

 

bump. This thread convinced me to purchase OEM trans fluid. I'm from SoCal but I'm better off with OEM stuff in this cold @$$ place.

 

I'm in Colorado and have used Redline MTL/MT90 for years now. No problems with using this combo and my CD009 tranny still shifts fine (although you need to let it warm up before shifting rapidly). Occasionally get the odd syncro to stick, but mostly that's just not hitting the rev match properly on a heel-toe downshift.

I use this same combo in my SCCA Touring 2 350Z racecar (and believe me, we run these cars HARD) and have had no problems either. Not sure what's up with all those who are scurrying back to the OEM gear lube.

 

I'm not sure. Perhaps the Redline cocktail works just fine, but running straight up MT-90 for me ended with bad results. Gas mileage went down dramatically probably due to extra drag from the higher viscosity. Also, when temps dropped below 30deg F which they tend to do a lot during Jersey winters I would get a nasty grind upon the first 1-2 shift after sitting all night. The only remedy for that would be to run in 1st gear for at least 10 full seconds to let the oil circulate before that first shift occurs. As soon as I went back to the OEM gear oil all was back to normal.