MT fluid in diff? (engine, transmissions, Nissan, axle)

[k374]

I have a 2004 Nissan Frontier XE, 4cyl, 5spd... just changed the manual tranny fluid at an indie shop here using Redline MT85 75w85 GL4 per the specs in the manual.

Now, the manual calls for GL5 80w90 in the diff but the service tech at the shop insisted that the MT85 would be fine so went with it. Now I read MT85 is not for use with hypoid type gears... i'm guessing this means in differentials?

Also read that GL4 does not provide the level of protection in diff applications and GL5 have sulfurs which provide this protection.

Should I go back and have the diff drained and refilled with GL5? Or am I reading too much into this?

[TrapperL]

You are reading correctly. You need to go back and have the dimwits at the shop change and FLUSH the axle. Then install the correct fluid. Excessive wear is happening as you drive it. Kinda like putting ATF instead of motor oil in the engine. Don't put this off.

[k374]

yeah, thanks TrapperL, that is what I feared, I have driven only less than 5 miles on it so going to do it first thing tomorrow morning... good god, frustrating when people in the industry don't know what they are PAID to know. WTF? I did not go to the Nissan dealer because the service guys there did not know what a GL-4/GL-5 specification even was I talked to a few service reps there and when I said are you going to use GL-4 they said "What's that?" I just left. This is the Nissan dealership.

[M3 Mitch]

This is a case study in why I DIY fluid changes. GL-4 is for transmissions, GL-5 is for hypoid drives. You can of course get "fit-all" fluids that are GL-4/5, but you know these are a compromise. One of the reasons I like Redline is that they offer a lot of specific lubes for specific applications - presumably they are optimized for the designated application, but since I don't work for them I can't say.

Some dealers have excellent but expensive service departments, some don't have much expertise, although these too tend to charge too much.