Well this is a Nissan Forum and Kinda off topic but listen up.

This is a 1992 Nissan Pick Up Truck.

What oil do I use for the rear differential ?? Can I use the same Oil that I use for the Trans ? GL-4 MT-90 ??

I read the Haynes book and its kinda not really clear.
if you look under manual transmission oil is sais GL-4
then under Differential oil is sais GL-5...but doesnt GL-4 exceed GL-5 ??

Anyone have a truck that knows, chime in

-matt

 

I have a '93 Nissan P/U, 2wd, reg cab, bare bones model. I had the rear diff oil changed like 6 years ago, but I didn't know anything about cars back then, so I used a coupon and had a shop do it. BTW, I also have the Haynes manual.

How many miles are on your truck? I just reached 120k.
Gotta replace the rear shocks this weekend.

 

GL-4 does not "exceed" GL-5...they are two different standards intended for different applications. You need to use GL-5 in your differential.

Manual transmissions use different gear designs than differentials do. The different designs/composition dictate different lubricants. GL-5 lubes have significantly more Extreme Pressure additives than GL-4 lubes do. Hypoid gears as used in rear differentials require the extra EP additives to protect the components against the shearing effect of the gears. On the other side, manual transmission components (synchros, etc) are often comprised of softer metals...the EP additives contained in a GL-5 lubricant can attack/damage those components....and that's why the OEM often specifies GL-4 for manual transmissions.

So if you use GL-4 in a differential, you will not have the protection you need; and if you use GL-5 in a MT designed for GL-4, you could cause damage to the components.

 

I have the bare bones modle, 92' P/U, 2wd, regular cab, no power steering. The thing is great. Just ticked over to 71,000 on it. Bought it two years ago with 56,000 and its been great.

Thanks for the information. Can you recommend any good Gl-5 like redline sells ?? I would like to put a good oil in the differential.

Thanks man

-matt

 

Haha..sweet. Yeah, 5 spd, no P/S, no A/C, no ABS. My dad bought mine back in '99 with 45k on it.

 

You shouldn't have concerns with the demands of high-performance or towing, so a good petroleum oil will work. However, if you want to install a premium synthetic, AMSOIL Severe Gear or Mobil 1 Gear Oil are two alternatives to RedLine. I sell a lot of AMSOIL Severe Gear to Titan owners. The early Titan models were notorious for differential problems. Many owners have switched to AMSOIL (and other brands) as an upgrade to the OEM fluid.

Before you buy/install any new fluid, be sure to check your manual to verify the viscosity...my application guide shows the diff on that truck takes 140 wgt gear oil over 10 deg C. Seems a little heavy for that application, but check it out...

 

In the manual under Differential Oil there is
Type................API GL-5
Viscosity...........See Manual Transmission oil chart

On the manual transmission oil chart, there is just 5w-20; 10w-30; 10w-40; and 20w-40 and 50. Sais nothing about gear oil

This is the same trans as a 240sx and I think the altima.

-matt

 

Any more help. I wanna get a good oil for the rear diff

-matt

 

Matt,

I think we're getting something mixed up here. In your first post you said your manual specified GL-4 for the MT...this is consistent with my application guide. GL-4 gear oil is also the recommended for both the 240SX and the MT Altimas. While some MTs can use motor oil (and some even use ATF), motor oils do not carry "GL" designations.

Your rear diff will require GL-5 gear oil (which is formulated with extra amounts of EP additives).

Sorry i can't be of more assistance, but it's hard to see what it is you are looking at unless you can scan it and e-mail it to me.

 

I would just like to know, whats a good GL-5 Gear oil that I can get for the rear diff ? What weight will I be using ? Underneath the viscosity rating for the diff oil, it sais refer to the manual transmission chart.

-matt