bjr

nevermind The website was completely wrong that I went to........

VQdriver

iTrader: (1)

MT85 here for at least a couple of years. Holding up great under all daily driving conditions thus far (knock on wood). I'd run either oem or that depending on whichever is less expensive. Maybe oem is cheaper on ebay?

OMG35S

+1 for OEM! I used Amsoil on both my diff and tranny and the shifts are rougher than with the old OEM tranny fluid! Swapping out the tranny with Nissan OEM ASAP. Makes me wonder if I should swap the Amsoil Diff oil out too? How do we know if the diff oil is working up to par? Noise/chatter from diff? If I don't hear a difference should I just leave the Amsoil Diff Oil in there?

VQdriver

iTrader: (1)

I know this is apples to oranges, but I used royal purple synthetic 80W-90 in the rear diff and when the temps fell below freezing it made a horrendous howling noise first thing in the morning for a mile or 2 of driving. Also, fuel mileage was way below it's normal at around 16mpg. I changed to castrol conventional hypoy C 80W-90 and MT85 and the rear diff noise instantly went away and mileage was back to normal. So if anyone needs a suitable diff oil use Castrol hypoy C. It's cheap and effective.

jninja26

iTrader: (1)

That's funny, as I've been hearing more and more negativity regarding Royal Purple products.

VQdriver

iTrader: (1)

I've heard through the forums that Royal Purple tests poorly in our motors in oil analysis threads. It's all hearsay though. It may indeed work just fine. Any new cheap oil will probably work well provided you change it regularly, but we like going to a whole new level here in the forums lol. I've gotten 2 conflicting reports on my own oil samples sent using GC 0W-30. So I stopped doing them and just drive and maintain lol.

I thought gear oil would be a no brainer. That being said, my diff was definitely howling at freezing temps first thing in the morning using Royal Purple 75W-90. It sounded like the oil wasn't moving around until some heat was built by driving. I replaced it with cheap Castrol Hypoy C 80W-90 and it worked super good. It's now the second change on the diff. I'm gonna let it go this time until 3 years for both trans and diff. No need to be getting smelly and oily under the car too often lol.

AARONHL

iTrader: (1)

Thanks for all the help in this thread!! Here is what I have to offer after changing my differential and transmission fluids, some things may have been covered already.

Nissan dealer $12.50/quart THIS IS THE RIGHT STUFF 75W-85 GL4 DON'T USE ANYTHING ELSE OTHER THAN WHAT DEALER HAS FOR TRANSMISSION


I don't have a lift and only two jack stands, so I used a 5/8" diameter hose to fill up the transmission while keeping the car level on the ground. If you need more than 3 feet you are doing something wrong.








I filled the differential with an AutoZone $11 suction pump. That is a MUST HAVE when changing the differential.

ronn1

iTrader: (1)

^^^^

this 1000%!! I don't know why people need to fix something that ain't broke in the first place. Just changed mine after 54K miles (08)..with no problems, but it was time. Shifts a little smoother now...but was fine prior. For the Differentil I used Mobil Delvac 75W90. This is NOT Mobil 1 LS..it has no additive for LS and is far superior.
You can check out the specs of Delvac here:

http://www.mobil.us/USA-English-LCW/...il-75w90.aspx#

AARONHL

iTrader: (1)

I'd also like to mention the Nissan transmission fluid is so good, the shifts are a lot less notchy, easy to get into the gear, and the tranmission doesn't make that squealing noise during cold temperatures. Who know what the dealer put in my car years ago when they changed my trans fluid that caused it to make that high pitched squeal

SilverFox006

iTrader: (3)

Need a little guy guys.

I ran up to the dealership today to buy the OEM Transmission and Differential fluids for my 2006 Touring Z, Manual Transmission.

The guys there asked if my car was limited slip or not which caught me off guard, b/c truthfully, I don't know and I thought it didn't matter. The guy at the counter said it did matter since the the fluid for the LSD had additives even though it was GL5 80w-90 (penzoil) which I went ahead and purchased.

So my question is 1) does it matter whether or not if I have limited slip diff. and 2)do you think it will be ok to us this fluid for my diff, not knowing whether or not I have LSD?

Thanks for the help.

VQdriver

iTrader: (1)

I own an oldschool 2005 G35, but I'm 98% certain your car only accepts 80W-90 GL5 gear oil for the rear diff. I believe you can use straight SAE90 if the ambient temp is always above 32degF as per my owner's manual. I can't say enough that I use inexpensive Castrol Hypoy C 80W-90 GL5 gear oil for my oem G35 rear diff and it works great.

As far as oem diffs go I believe Nissan only uses a VLSD (viscous type) which operates independent of gear oil, the only time it matters about additives or certain types of oils is if you're running a clutch type differential such as a Kaaz or Nismo aftermarket diff. In my experience, the best oil for a clutch diff is Motul PA90 which makes operation smooth and quiet. I use that in my drift car's Kaaz 2 way clutch diff. Hope that helped.

VQdriver

iTrader: (1)

Nissan MTF or Redline MT85 ftw! Use whichever is cheaper. As long as the rear diff isn't howling when the temps are at or below freezing you're ok. I'd be picky about that and make sure you're running 80W-90 GL5 gear oil in the rear diff...

SilverFox006

iTrader: (3)

So as long as I'm running the 80w-90 GL5 in the differential, Limited slip or not, I should be ok?

VQdriver

iTrader: (1)

Lol. I posted 2 posts above specific to you. Sorry my posts tend to be wordy. Yep, give it a go...

jtbinvalrico

An often repeated question in this thread is what size are the crush washers. I took a minute to measure mine during the fluid change today. It appeared to be the same washer used on the fill and drain plugs on both the MT and the diff.

It looks like aluminum. Here's the measurements: OD 24.10mm, ID 18.15mm, Thickness 1.5mm (these are what were on my car, they fit just fine, but I can't verify if they are Nissan OEM or not).

While it was evident that the prior mechanic had use a 3ft cheater bar to tighten the bolts well beyond the torque spec, the crush washers looked rather un-crushed and in otherwise good shape, so I re-used them.

Here's what they look like:



What really prompted me to change the MT and diff fluid was finding a receipt in the stack of paperwork that came with the car indicating that a 75w-140 gear oil was put into the diff. Even though the car drove fine, I figured a proper spec oil wouldn't hurt.....and why not do the MT since who knows what was put in there.

I went with Nissan's MTF in the MT and Valvoline 80w-90 in the diff. A bit smoother shifting now, but the most noticeable change is how easily it'll go into first while rolling. Before, it had to be at a full stop, but now I can slip it into first while rolling at a decent clip. Not a big deal, but perhaps indicative of things working a bit more smoothly......and it means I don't always have to choose second when first might be more appropriate at slower speeds.

The Nissan MTF was an easy pick after reading the 26 pages of this thread. The diff oil.....not so much. I just figured I'd get the thing back into spec before fooling with it any further. I really don't notice a difference in the diff, though. But I'm sure parts inside are happier and it's probable that the change will reveal itself in long-term wear and fuel economy.

+1 on using a suction pump gun. This one from HF had a nice capacity and worked great for me:

http://www.harborfreight.com/oil-suction-gun-95468.html

RawrXTC

I'm changing out my diff and tranny fluids tomorrow and I'm a bit unsure of what to torque the fill and drain plug of either of them to. The guide says "5. After diff/trans is drained, reinstall drain plug. 23 - 28 ft-lbs for transmission; 55 - 61 ft-lbs for rear diff." but I saw in another thread that the differential should actually be about the same as the tranny (23-28 ft-lbs). Can someone please clarify? Thanks!

VQdriver

iTrader: (1)

I've changed both a couple times without the use of a torque wrench. I'd say a good "forearm tight" so that the plug is snug is sufficient. I'd say 55ft-lbs sounds a bit too much for the rear. The plugs are the same size.

RawrXTC

Awesome! Thanks for the reply, so it's like an oil pan drain plug; just get it snugged and it should be good.

jtbinvalrico

If you are getting further into your own maintenance, now is a great time to pick up a torque wrench or two. The plugs you referenced need to be torqued to 25 ftlbs. If you are removing your wheels for servicing, they need to be properly torqued at 80 ftlbs (at least for stock wheels).

You can get some inexpensive torque wrenches at Harbor Freight. They are cheap and they work just fine for regular maintenance. The primary objective is to stop you from over-tightening the bolts, since under-tightening is rarely a problem for most of us. If you are going to be torquing the internals on an engine or tranny, you'll want to consider a higher quality wrench.

This 1/2" is good for wheels and bigger bolts:

http://www.harborfreight.com/1-2-hal...rench-239.html

This 3/8" will work for everything else:

http://www.harborfreight.com/3-8-eig...rench-807.html

RawrXTC

Thanks! I got them both. Been doing my own maintenance for awhile and they do come in handy!

As for the maintenances themselves, I used Nissan OEM 75w-85 for the tranny like the picture someone posted earlier in this thread. For the differential I used Valvoline 80w-90 after searching and reading every thread it was the only thing I saw with little to no problems at all. The crush washers I did not replace because the salesguy at Nissan did not give me the right ones..and this is not the first time they have done this. The last time was a gasket for an oil cooler. I also did the AC compressor belt in which I didn't realize that the alternator belt had to come off in order to remove the AC belt. I did not replace the alternator belt because prior to doing the maintenances I did a visual and the belt looked fine, but after taking it off it was actually starting to crack, but I didn't have enough time to run to the autoparts store to get one. This is getting really long but just wanted to mention that prior to the tranny fluid change the shifting was a bit notchy and did not want to go into first when I'm rolling at a pretty slow pace. After the fluid change it shifts waaaayyy better. No "notchiness" and goes into first like butter.


P.S. I've owned this car for about 3 weeks so I have no clue what was done to it or in it before, but both fluids came out looking very clean with no metal shavings at all.