Due for differential gear oil change...
 

Quick search suggests that the consensus preference is 2 qts of Redline 75W90 synthetic.

However, is this oil the appropriate choice for a VLSD???

I was under the impression that this oil is best suited to open diffs -- is this incorrect? I believe there is a variant without friction modifier additives -- would that be better?

Can someone with a good working knowledge of VLSD's confirm that Redline 75W90 (or a variant or another oil entirely) is the correct choice?

Several threads raise these questions, but don't seem to arrive at a clear answer, at least to me... :confused:

Also, any difference in the diff for the 7AT vs 6MT -- mine is the auto.

Plan to order needed fluids and gaskets as noted here within the next day or two...

Thanks in advance! :tiphat:

EDIT: Okay, further searching suggests that the regular Redline gear oil is preferred and that the diff itself is actually sealed (?).

Other suggested alternatives I've found include:


Lubro Moly Gear Oil Syn 75w-90 GL-5 Diff

Richmond Gear Oil Syn 75w-140 GL-6 Diff

Shell Spirax synthetic 75W90 gear oil.

Curiously, NONE of those are the same weight as the factory oil?

Huh?

Er... help?

I presume you read this already:

http://www.the370z.com/diy-section-d...il-change.html

Redline also makes 75-90NS but I have seen that more for trannies then rear ends (I use it in the Subaru for example, but the rear end gets 75-90 GL-5 gear oil).

I am a few years from needing this maintenance so I have not spec'd the fluid myself. I see it requires GL-5, and if its a sealed diff 75-90 should be peachy. Its rare these days to need modifiers and other items. If you are in doubt, go OEM.

In many cases, OEM fluids are absolutely fine. Some folks just feel 'smarter' not using OEM fluids. Few folks on the inter-tubes have the requisite automotive and/or mechanical engineering degrees and practice automotive lubrication and testing to respond authoritatively to the many debates on the subject :D

I have used OEM fluids for some applications...and in others aftermarket has been the ticket.

Enjoy the drive,

- b

Subscribed!!

:iagree:

Not sure what you should or shouldn't use, but I put the Redline in a few months ago.

Cheapest price I found if you're going that way:

Red Line 75W90 GL-5 57904 Differential Fluid - Nissan performance parts

Thanks for the input, guys :tup:

Question: Why don't people use the recommended 80W90 oil? Is it because people like Redline and Redline doesn't offer that viscosity, or is there another reason?

Did a quick google search on synthetic GL5 80W90 gear oils and found a few other alternatives:

Mobilube HD Plus 80W-90 Gear Lubricant

http://www.wolfoil.com/update/docume...ion/2312ce.pdf

Some details on different gear and trans oils here
http://www.widman.biz/uploads/Transaxle_oil.pdf

Suggests a GL6 might be even better? I will search for one...

Here we go -- what about this?
http://www.torcousa.com/technology/SGO.pdf

Castrol Australia - Manual Transmission Fluid

A paper by Amsoil people might find of interest (not independent, obviously, but still informative)
http://www.synthetic-oil-tech.com/Ge...te%20Paper.pdf\


Thoughts?

When should this be done? I am just over 31k miles...

Apparently around 30K, though some like to do it sooner.

I'm still trying to figure out which gear oil to use... :icon14:

One thing to note is the fact that Nissan changed the rear diff recommendation from year-to-year....
Rear Diff: GL 5 80w90
In the 2010:
Rear Diff: 75w-90


The LSD is sealed. No need for a friction modifier, etc.


I imagine most people use the Redline because it is a good oil that gets good results. A slight difference in viscosity shouldn't/doesn't seem to cause any problems.

That's very interesting -- mine's a 2010, too -- although I doubt there's anything different mechanically. What parts of the diff actually get lubed if the LSD is sealed unit?

Okay -- I think that settles it for me then. I'll go with Redline.

Thanks! :tiphat:

I did it at just 14-15k and it was mud and full of metal deposits (normal from breakin I assume)... most people have the same experience. I plan on changing mine more frequently than they recommend.

So to summarize Red Line 75W90 GL-5 57904 Differential Fluid ..
But which one for the 7AT tranny? I just cracked 30K and I want to do both on my next schedule service.
Thanks

No need to do it -- non serviceable. If you want, check it around 60K.

No need to do the Tranny or differential?

If you mean no need to service tranny... then go with the Red Line 75W90 for the differential?

Thanks in advance.

Any quality synthetic 75w90 is gonna be fine in the diff. Personally, I like Royal Purple for my diff, but I doubt it makes a huge difference between the good vendors.

On the 7AT: the official Nissan stance is that the fluid inside the thing is good for life and never needs any changing. However, at a mere ~18K miles my 7AT fluid looked like it was about done for. Keep in mind I drive in a lot of summer heat and I use/abuse the 7AT pretty hard. I wouldn't think it's wise to go more than ~20-30K miles without changing out the fluid, unless you always drive it like a grandma. A little 7AT fluid every 20K isn't a big budgetary concern anyways.

Any quality Nissan dealership can do it for you, but you *do* need to use a dealership because only they have the Consult-III diagnostic tool to tell them the 7AT's internal temperatures to set the fluid level correctly. I really have no idea why Nissan went down this path of trying to make the fluid a "good for life" item, I can't even imagine an angle it makes sense from business-wise. It might have mostly been that this tranny requires the aforementioned precision refilling and they didn't want to say "You have to change this fluid regularly, but you can't do it yourself", so they opted for a very long-life fluid.

I plan on doing mine every 15,000 kms

The first time at 5000 kms it was a disgusting mess. Reports are that it needs frequent changes due to high operating temps. Plus it is a simple fluid change to do for low cost. Can't hurt.

Keep in mind that I'm not trying to say that the fluid is good for 100K miles or anything, but I've recently read that you can't really go off the color of fluids as a judgement of how much life is left. What do yall think about that?

Makes sense since regular oil is the same way. People think just because the oil is dark/black that it's dirty or time to change. The only thing you can do is send it off for oil analysis to see just what happened to the oil.

$20 for peace of mind....

I'll change my oil.

Well the topic drifted to AT fluid above, hopefully everyone changes their oil :) When I say it looked bad at 18K, I didn't get an analysis done, but that wasn't just color either. You can feel the difference slipping the fluid between your fingers, between fresh Nissan Matic-S ATF and the stuff in my car. It's not real fluid analysis, but it's not useless either.

The only reason I even noticed is because I was installing an ATF fluid cooler at the time, so I had to buy an extra quart or two to fill up the new capacity, and disconnect the lines and see the old fluid in the install process. I did the cooler install at home by pre-filling the cooler core and most of the new line length, and being very careful about capping things off and minimizing spills during the hose hookups. And then I took it to the dealership for something unrelated a couple weeks later and had them swap the fluid and re-set the level perfect.

^^ good point also!!

I have used Amsoil and Motul... Probably amongst the top 3 for choices. I didnt notice a difference in one vs. the other but the motul was a little more expensive.
The Differential calls for GL5 oil where the manual trans calls for GL4.
Check the link below its direct from Amsoils site. They were the FIRST in synthetic oil and their stuff is great! I used in my engine, trans and differential and put in all my other cars as well!

AMSOIL Product Recommendations - 2010%7cNISSAN%2fDATSUN%7c370Z%7cM

Just sharing this, because I am pleasantly surprised:

After replacing factory gunk (which looked not too overly gunky, actually) with fresh fluid by Redline, less drivetrain vibration on hard shifts.

Am I imagining this!?

Anyway, glad I changed the fluid, placebo or no.

wth is a rear differential oil change? is there a dip stick? i know theres transmission oil, engine oil, brake fluid, coolant, battery fluid, windshield fluid, power steering.

but whats rear differential oil? and dip stick, can someone PM me, i may not get to see this again, might forget

The rear diff has a drain plug and a fill plug, and yes, it has a fluid that needs changing. It's in the service manual if you need details. The rest of the thread has info on fluid recommendations. Tracking the VLSD (yeah I know, getting rid of that's "on the list"...), the fluid definitely needs a regular change. I've been doing mine roughly every other oil change.

Amazon has it for a few bucks cheaper including shipping:

Red Line 57904 (75W90) Synthetic Gear Oil - 1 Quart : Amazon.com : Automotive

that mt90 works AWESOME in my trans. I can now quick shift 1st to 2nd and not grind at all. A little thicker than what is called but works amazing thus far. I changed both diff and trans at 36k miles. Diff was really dark and syrupy, but thats about what the manual calls for in reguards to changing your diff oil.

Don't use MT90 in the differential!! You'll see right on the bottle!

Yeah. The weight is close but you need a GL5 oil for the diff, badly needs the high pressure additives.

I didn't use mt90 on my diff. I used 75w90.

In other words I changed both at the same interval.

I'm changing my rear diff tomorrow with Royal Purple Maxgear 75W90.
The store I shop at carried every redline oil except the gear oil.
Anyone used this with no ill effects? Just want to make sure I'm using the right product and there isn't some other royal purple oil they didn't carry I should use instead. The staff were no help. It says it has a friction modifier built in.

If its not a GL-5 oil then go return it and order your diff oil from the website.

it's GL5 I made sure of that. Says it's for front and rear diffs too.

Should be good to go then.

I drove my car when it belonged to my dad at a track and the diff started binding after only one session. When I bought it from him I changed the diff oil to Redline 75w90 and did another track event with no issues at all. I plan on upgrading the VLSD at some point as well but while I have it stock I'll stay with Redline 75w90.

Interesting post I just stumbled upon. The 2014 service manual states 20K mile diff oil changes.