maybe the evo's are special? I know at least 10 guys personally in the NW who run aftermarket tranny fluid in their 6MT's and they have all said that it is better than OEM.. only one guy with a G37 sedan who didn't notice a butt dyno improvement and switched back to OEM

 

Do you think i should try like royal purple or ams or something other then oem?

 

I will be doing the transmission and diff fluids soon but i keep hearing from nissan mechanics that only OEM GL-4 fluids that are within 75W-85 or 75W-90 should be used in the manual tranny as other products tend to cause problems. I was wondering if using mobil 1 75W-90 would be a good alternative as i use it in my engine and it performs like new everytime i change the oil. For the Diff however i think the Gl-5 80W-90 is the only option since i wouldnt wanna damage anything back there with using some cheap oil. and dont forget to change the clutch fluid and flush the line with the OEM brake fluid when doing the transmission oil or the symptoms of sticky clutch might return

 

Seriously hope this is a HUGE typo.

EDIT: I used Amsoil MTF in my 6MT and at first I didn't notice much of a difference but now when the engine is cold, it's clearly smoother. Also have Severe Gear in the diff. Obviously can't feel a difference but the old fluid was very dark when coming out. If anything, I'm going to change my diff fluid a lot more frequently because there's not much that goes in there so I think it tends to wear a lot faster than the MTF.

 

Lmao 75w90 in the engine, that has GOT to be a typo

 

I personally can't recommend Royal Purple motor oil both based on my experiences using it in a circle-track race Camaro that my buddy owns and we both work on, and also based on numerous poor UOA reports over on BITOG(Bob Is the Oil Guy forum). Stick with Amsoil, German Castrol, or some other supposedly "synthetic" oil that you can buy off the shelf at the store for your motor oil. With the rate of Oil Consumption problems on '05 and '06 G35 Coupes, stick with what works and don't risk contributing any extra risk factors by chancing it with risky oil brands. German Castrol (0W30, the kind you can only get at Auto-Zone) seems to be the general consensus for most compatible oil with VQ35 motors based on a bunch of UOA reports.

If your car is an '06, you can probably get away with using Amsoil or Redline gear oil in the transmission, but many of us who have the '03 and '04 6MT's have to be careful with tranny oils because our transmissions are notoriously particular about gear oil and the transmissions are inferior to the newer ones used in the 05+ cars. For those of us who have '03/04's 6MT's, it's generally best to stick with the OEM Nissan Gear oil. Personally, I'd probably play it safe and do the same thing with your '06, but I haven't done the research to back up that claim on your specific car.... so you'll have to make that decision yourself. But if you're content with the way your car shifts now, it might not be a bad idea to stick with the OEM fluid. One thing to keep in mind though is that the recommended viscosity of the gear oil in our transmissions is a strange weight(75W-85 GL-4) that you can't buy right off the shelf except for when you buy the OEM stuff. Typical weights for gear oil are 75W-90 or 80W-90, so they aren't an exact match to the OEM spec.

If you do decide to go OEM for the tranny fluid, buy it from a Nissan dealer, not an Infiniti dealer. The same exact gear oil will be about $2-4 a quart cheaper at Nissan than it is at Infiniti.

 

Thats kind of a relief seeing how expensive royal purple is lol. So far im thinking amsoil for the engine (5w30?) and oem nissan fluid for the tranny. Now what about for the dif?

Thanks again

 

Don't get too excited about the cost of Royal Purple.... most of the oils I recommended cost just as much, if not more than Royal Purple. If you get Amsoil, you'll probably have to pay a little extra per quart over list price to have it shipped to your house. If you plan on using Amsoil, it's probably worth it to become an Amsoil Preferred customer. It costs like $20 a year, but you get a significant discount on their products. If you buy a lot of their products, it makes sense financially to do it.... especially if you bulk together your orders with other people in your household or some of your friends, and purchase all of their stuff through your account. Buy the stuff you need in bulk though, so you can save on the excessive shipping costs associated with placing several small orders.

I use Amsoil Severe Gear in the Diff in my G35 and both differentials in my truck. It works great, not that the original stuff didn't work just as well(the only way you're likely to notice a difference is if the diff. fails anyways). I have no qualms spending a good bit of money on top-notch oils for things like transmissions, transfer-cases, and differentials, since those fluids will be in there for a long time and also since the cost difference over the life of the car between a lesser oil and an expensive one is not that big of a difference. Most people probably only change their diff. fluid a max of 2 or 3 times during their ownership of a vehicle anyways.... unlike motor oil which gets changed every 3-5K miles. The cumulative extra $30 spent on top-notch gear oils for the tranny and diff. over the lifetime of your car(vs cheaper/lesser oils) is worth it IMHO.

 

Nissan MTF fluid in the tranny 4 qts for drain and fill. 2 qts of GL5 (Mobil 1) diff fluid, 5 qts of oil and don't really care what it is since 2 months later it gets changed (penzoil, mobil, castrol)...what ever is on sale at that time.

 

Regardless of the service interval for differential oil, when you actually change it, you'll see just how much wear it can get in a relatively short period of time. It goes in clear and comes out dark black, plus the plug will have metal shavings stuck to it. I'd change that more often than the MTF IMHO.

The MTF I drained looked relatively good good with very little wear to it on the other hand.

Power steering fluid is something people frequently overlook as well which is another fluid that wears surprisingly quickly. I'm not as religious as some people who pump out and refill the resouvoir 6 times + but I did notice a difference in power steering feel doing it the first and second time. After the third round through with my pump, it felt the same so I just stopped.

Wish I could find a place that sold the German Castrol 0W30 here in Canada.

 

haha noo i would never put 75W90 in my engine!! it would be like putting sludge in there lol i meant using the mobil 1 product line for the MTF fluids but ya i am in toronto as well and there is noo place that sells that castrol german 0W30 i tried looking for it but couldnt find it so i settled for the 0W30 from mobil 1. Just curious how did u go about doing the power steering some people tell me it never needs to be changed for the life of the car

 

at the 45k mark for my transmission, i used redline. My car was shifting rough and I'd get a bone cracking sound when I shifted to 6. Now its gone, and my car shifts beautifully, 5k miles in.