Differential Fluid

jdTrader said:
doesn't AWD have a front and rear differential and transfer case? Sorry if stupid question....because I thought 2 differentials and a transfer case oil had to be changed.
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Yes sir, AWD have 2 diffs and a transfer case. Both diffs and the transfer case oil need to be replace.
 
NJ-R'sFX35 said:
I forgot to ask u. Do you have to replace gasket/washer on the drain plugs?
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I didn't replace the washer. I take the drain plug off, drain the fluid, wipe the plug clean and then reinstall. No problem for far since the new year.
 
dont forget about the actually transmission, some people often assume that once they get their diffs taken care of they are done. But you still have the transmission. So front and rear diffs, T_case and transmission.
 
TurTLeG said:
dont forget about the actually transmission, some people often assume that once they get their diffs taken care of they are done. But you still have the transmission. So front and rear diffs, T_case and transmission.
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I know that but, don't know which path to take with the transmission. I read this thread https://www.infinitiscene.com/search/1/?q=433-HOW-TO-Changing-Transmission-Fluid. And seems nobody agrees on what is the right thing to do with the tranny, some say drain the pan and refill same amount you drained. Others say that the way Shralp did it is right, and there's another guy who says that it is not good to do the tranny oil at all. So, :ooh: ...
 
There is no wrong or right. The only wrong is not doing it at all.

Drain and fills are the best/safest method. For the transfer case and diff, all u can is drain and fills. It should get out about 95% of fluids out. With the auto trans, most cars are about 10-12 qt system. From the drain plug u get 3-4qt. So 1/3 new fluid.

You can go further and take off the return line but u risk running dry/low. Wasting fluid but u will get maybe 8-9 qt of new fluid.

I do drain and fills every 30k vs the recommended 60k. So I don't see a point ay doing the return line method.

Either way your way better off then the people who never take care of their fluids because they don't know/care for it.
 
I have looked through all the differential threads and it seems like they all get close to addressing the question but never do...

If the factory spec is 80w-90, why is no big deal and common for everyone to use 75W-90 on the front/rear diffs?

Also, ranking wise, Royal Purple, Amsoil, Mobile 1, Red Line, Valvoline, Lucas. Is that an accurate ranking? Are they all going to be about the same either way as far gear oil is concerned, just get whatevers available?
 
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75W-90 will be fine to use in your diffs. The 75w-90 will give your diffs better cold weather performance compared to the oem spec 80w-90 weight fluid. When the oil warm up, the 75w-90 will protect like the 80w-90 weight. You may actually have less of a drive train loss and better protection due to reduced friction if you use a 75w-90 synthetic fluid compared the oem dino fluid. I like to use Royal Purple 75w-90 myself and Royal purple Transmax fluid in the transfer-case.
 
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carguy75 said:
75W-90 will be fine to use in your diffs. The 75w-90 will give your diffs better cold weather performance compared to the oem spec 80w-90 weight fluid. When the oil warm up the 75w-90 will protect like the 80w-90 weight. You may actually have less of a drive train loss and better protection due to reduced friction if you use a 75w-90 synthetic fluid compared the oem dino fluid. I like to use Royal Purple 75w-90 myself and Royal purple Transmax fluid in the transfer-case.
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I see. So if I live in a temperate climate, i.e. Bay Area, CA. where we dont get anything close to a cold winter, ever, Would 80w-90 be more applicable? So do FX's in say, Arizona, run 80w-90 because they see a lot of 100+ deg weather?
 
giantsoobs said:
I see. So if I live in a temperate climate, i.e. Bay Area, CA. where we dont get anything close to a cold winter, ever, Would 80w-90 be more applicable? So do FX's in say, Arizona, run 80w-90 because they see a lot of 100+ deg weather?
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If you run a synthetic 75w-90, then you would have better protection that when using the non-synthetic 80w-90 used by Nissan in your high temp area. The syn 75w-90 weight better protects the gears from higher temps compared to the oem 80w-90. Plus, you will have a hard time finding a company that makes a 80w-90 in synthetic, most are made in the broader ranged 75w-90 or thicker. It is the same concept as using a synthetic engine oil vs. conventional oil, except it applies to your diffs. Synthetic gear oil is more slippery and protects better than conventional gear oil in my opinion, however I am sure that some would disagree.
 
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I see. Well I went with Red Line 75w-90 full synthetic. I was going to go Royal Purple but at $24/qt, i was a little dissuaded. The guy at NAPA does top fuel drags on the weekends and said that he only uses Red Line after he found that it in deed ran a cooler temp gear. He said that usually when they swap gears after each run, they HAVE to use gloved to pull the gears or else it will cauterize the skin immediately, but when they started using Red Line, they can hold the gear just long enough to pull and drop it w/o gloves. That was his proof and he sold me.

No joke on that smell either. My girl was pissed when I started cleaning out the pump in the sink and the whole kitchen smelled of gear oil for 30 minutes.
 
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giantsoobs said:
I see. Well I went with Red Line 75w-90 full synthetic. I was going to go Royal Purple but at $24/qt, i was a little dissuaded. The guy at NAPA does top fuel drags on the weekends and said that he only uses Red Line after he found that it in deed ran a cooler temp gear. He said that usually when they swap gears after each run, they HAVE to use gloved to pull the gears or else it will cauterize the skin immediately, but when they started using Red Line, they can hold the gear just long enough to pull and drop it w/o gloves. That was his proof and he sold me.

No joke on that smell either. My girl was pissed when I started cleaning out the pump in the sink and the whole kitchen smelled of gear oil for 30 minutes.
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I see. Red line is a great fluid to use. How much does it cost a qt?
 
giantsoobs said:
It was around $13-$14/qt.
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i use redline d4 for the transmission and transfer case..redline for the diff, as well as engine oil, power steering and redline water wetter for the radiator...the best stuff in my opinion...
temp in taiwan gets really hot so the best is needed..
 
I stuck with oem as i was advised by that so bought it at the dealer. Now i am thinking with all the performance parts going on if it wasn't a better idea to upgrade that as well due to the extra heat......anyone...??
 
I posted this in the other differential thread as well - just thought I'd share with this group too - I originally posted back in August:

So I changed my diff and transfer case fluids around 30K miles. At that time, the Transfer fluid looked a little bit dark, but overall in pretty good shape, the front diff, was pretty dirty and the rear diff was practically black. I just did it again at about 81k miles (all 3). The Transfer fluid looked like the day I put it in and the diffs both appeared to be in really good shape too. I'm sure that this is primarily due to the standard wear during the first X (10k?) miles on a new car, but I was pretty surprised at both 1) how dirty it was the first time and 2) how clean it was the second time.

I am not in any way an Amsoil fanboy, but I used Amsoil 80w-90 (the exact spec called for in the manual) gear oil for the diffs and Amsoil Universal ATF (with the Matic D/J spec) for the Transfer case at both the 30k and now the 81k service.

Just thought I'd post my results.
 
Nice, thanks for the info. I have been replacing my with Mobil1 gear oil. Next time I should try some Amsoil or Red Line.
 
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