Hey guys, I've owned my 06 G35 for 5 months now and its been great! My gears have always been a little notchy, but I've adapted and learned how ti shift it smoothly. But i about a week ago i got my transmission oil changed, and ever since my second gear is pretty clunky, and sometimes even grind when when the clutch is fully in. Ive been told your not supposed to change it but reuse it. But how big of a difference could it make? I can put it into second but i have to force it and i don't know if thats a bad thing or not. Because when i force it theres no notches, it kind of slides in. Does it have something to do with the transmission oil, or I've heard something about a throwout bearing going bad. Any info on this?

 

Not supposed to change what? Confused.

 

The trans oil. Im not sure but a friend of mine told me your supposed to recycle the old transmission oil.

 

What brand and kind of oil did you put in?

Our cars are really REALLY finicky about gear oil in the tranny. The best thing to use is the OEM Nissan manual tranny fluid. It's expensive but worth it for not having to worry about problems. It's cheaper to buy it at Nissan than Infiniti.

 

Yes, this happened to me once when a Nissan mechanic put in something other than the recommended Nissan Fluid for some reason and it was real notchy. He replaced that with the correct fluid and everything was fine.

 

You must put in Nissan Matic J or the replacement, Matic S last I checked. Otherwise it's a synchronizer issue it sounds like.

Try double clutching it into second, if it goes very smoothly after a double clutch shift it should be the synchro which has failed - I am serious.

 

But also it grinds sometimes while the clutch is fully in does that have anything to do with the oil?

 

no i tried double clutching plenty of times but it does still not go in.

 

Why did you change the transmission oil?

Did you read that in your owners manual?

Follow the procedure in the FSM

I think you just found out!

FWIW I traded in my 06 G35 6 sp with 171796 miles and never changed the transmission oil. It still ran like new when traded in and never had any transmission issues.

Never try to fix anything that isn't broke. If you are not sure read your owners manual

Telcoman

 

I do not currently own an owners manual. Well i changed it because i thought it wasn't as smooth as it should be, and also i wanted all new fluids in the car so it would be "fresh"

 

https://owners.infinitiusa.com/conte...-G37-Sedan.pdf

http://www.nicoclub.com/service-manu...6_G35_Sedan/mt


See page MT 9


http://www.nicoclub.com/service-manu...6_G35_Sedan/ma

See page MA 10

Telcoman

 

This is utterly terrible advice and you should never tell this to someone who has an open mind and is trying to learn to work on cars

Fixing things and doing maintenance are completely different concepts that shouldn't be lumped into the same bucket. Not fixing something that isn't broken might be acceptable for the replacement of mechanical parts (such as a car battery, exhaust system, headlights, and pulleys), but nobody should ever neglect maintenance on their vehicle or you'll almost definitely end up with seriously significant and expensive parts being broken way before their normal life expectancy (transmission, motor, etc).

Think what would happen if you just decided to never change your motor oil? What if you never changed the timing belt on a vehicle with an interference motor? Never replaced your tires until they failed?

The reason you change your manual transmission fluid (or any gear oil really) is that it begins to accumulate microscopic fragments of metal shavings from the gradual wear of the gears, bearings and other internal transmission components as they wear over the course of a typical 50K mile or so service interval. That contamination of the fluid makes it lubricate worse because it starts to have a sort of sand-like wearing effect as it gets worked through the moving gears and bearings. Larger fragments would sink to the bottom of the transmission shell or get stuck to the drain plug if it has a magnetic end on the bolt, but not the microscopic stuff. All gear oil also shear over time and when the correct viscosity is not maintained, an increase in micro-pitting and gear wear will likely occur. Higher quality gear oils tend to be more shear resistant than lower quality oils, but they all shear and require changing to keep the internal parts that they are lubricating from wearing and allow them to operate smoothly.

Moral of the story... change your oil and do your maintenance, but do you research ahead of time and use the right materials and tools when doing it.

 

The OP never bothered nor searched to read either an owners nor the FSM manual

Never said anything about not changing motor oil. I did 53 oil changes on my previous 06 G35 and just did the 22nd on my current 2012.
Our vehicles have timing chains that do not require replacement.
My tires get replaced when they have 4/32" of tread left

You are correct about the microscopic particles but I've never had a manual transmission failure for not changing manual transmission oil in the many manual transmission vehicles that I've owned a few of which I put over 200k miles. Even when clutches were replaced at that mileage interval the transmission was left alone as there were no problems with them.

The OP and others can make their own decision as to how long they expect a newly purchased eleven year old vehicle to last and how much money that wish to pour into it.

I have not purchased used vehicles for many years. I only purchase new vehicles that come with all new parts and a warranty. I am not concerned with who purchases my used vehicles after I'm done with them.
Agreed!

Telcoman

 

Although immoral, it makes sense.

I only repair lower priced bikes enough to get them street ready again, but keep my cars and higher quality bikes in good enough condition for the third owner.

Probably waste a lot of money doing so.

Regardless, the service manual for this generation recommends fluid changes periodically. The newest ones are sealed, but use a different fluid.

 

I know our motors have chains... it was an example to apply to vehicles in general.

It's bad advice to tell someone like this not to do a general maintenance item "if it ain't broken", because you don't know far or literally they might take it. Just because you never had a transmission failure doesn't mean it's fine to never change the gear oil. I personally can notice a huge difference in certain vehicles with how easily they shift once the transmission fluid starts to get past around 60k or so miles. I just changed the fluid on my Tacoma a month ago since I was way overdue and it was starting to shift noticeably rougher with gear engagement, and I was very surprised at his much smoother it shifted using a new batch of the same fluid that I had in before. That was the most noticeable difference I've ever seen before with fresh gear oil impacting shifting... but it's also the longest I've ever gone between manual gearbox oil changes on any vehicle in my 24 years of working on cars.

You are on a forum where advice is being given and saying it's OK to never change manual transmission fluid because you've never experienced a failure as a result. That's just bad advice.