Rear Differential Fill Level ?

Ok I see the confusion. The drawing makes it look t like there’s a fill hole on the top of the housing towards the front. No such beast - the line for “oil level” is just pointing at the oil. There’s not actually a hole there where the line goes across the top of the housing.
Exactly.
 
I am not going to tell anyone what to do - but both of the Nissan's in my sig have the same diff as the OP's - Nissan C200K.

I have no idea what the drawing indicates but every 30K I drain and fill till it runs out the fill hole. I then let the excess drain till it stops for a minute, put a little RTV on the fill plug pipe threads like they say (the drain plug is a regular thread with a re-useable aluminum gasket and doesn't need RTV) and stick it back in.

I have owned both since new. One has 400K+ now, and the other has almost 200K. I have had zero issues with either - not even a leaky shaft seal.

Now I have likely jinxed myself. :(
 
I am not going to tell anyone what to do - but both of the Nissan's in my sig have the same diff as the OP's - Nissan C200K.

I have no idea what the drawing indicates but every 30K I drain and fill till it runs out the fill hole. I then let the excess drain till it stops for a minute, put a little RTV on the fill plug pipe threads like they say (the drain plug is a regular thread with a re-useable aluminum gasket and doesn't need RTV) and stick it back in.

I have owned both since new. One has 400K+ now, and the other has almost 200K. I have had zero issues with either - not even a leaky shaft seal.

Now I have likely jinxed myself. :(
thanks for the info

the diagram I attached in post #14 notes that the washer should be replaced and that the drain plug gets RTV too.
 
thanks for the info

the diagram I attached in post #14 notes that the washer should be replaced and that the drain plug gets RTV too.
You don't by chance have a manual transmission do you - because that means you might have a M226 not C200, and it might be different than mine.

It does in fact say the gasket should be replaced, but I never have. Its basically an aluminum washer that mates between the plugs machined face and a machined face on the diff. I do have a spare I ordered for my very first change - and never have used it. You do as you wish - as I said I am not here to tell anyone what to do.

The drain gasket does not say to use sealant - which would make no sense since its a standard thread with a gasket on a machined face.

The fill plug is just a pipe thread - so it does make sense to use sealant.

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You don't by chance have a manual transmission do you - because that means you might have a M226 not C200, and it might be different than mine.

It does in fact say the gasket should be replaced, but I never have. Its basically an aluminum washer that mates between the plugs machined face and a machined face on the diff. I do have a spare I ordered for my very first change - and never have used it. You do as you wish - as I said I am not here to tell anyone what to do.

The drain gasket does not say to use sealant - which would make no sense since its a standard thread with a gasket on a machined face.

The fill plug is just a pipe thread - so it does make sense to use sealant.

View attachment 243710
thanks, no worries, I appreciate you sharing your experience.

In post #14 I attached a diagram and parts #6 (drain plug) and #15 (fill plug) have a symbol next to them and the legend notes for the symbol say to apply RTV
 
I always stop once the gear oil starts dripping from the fill hole and then install the fill plug. I have only used Teflon tape or nothing at all on fill / drain plugs and zero issues. With your truck, I would use RTV since it says to.
 
I have no idea what the drawing indicates but every 30K I drain and fill till it runs out the fill hole. I then let the excess drain till it stops for a minute
I suspect more equipment makers will move to that method so they don't tell people in documentation to "touch" the oil. It accomplishes the same thing.
 
Something tells me that when I did a recent T/C fluid exchange on my RX, using the filling until it spills method is considered overfilled. I fear that it may foam using this fill method and measuring and then reaching for the fluid is more accurate.

Don't get me wrong, I've always used the fill until spill method, but recently it just seems inaccurate with possible harmful consequences to the driveline.
 
I suspect more equipment makers will move to that method so they don't tell people in documentation to "touch" the oil. It accomplishes the same thing.
You're onto something! If one can sue for hot coffee, maybe I can sue for touching ATF that's ~130* while checking a modern automatic!! Cha-ching! I'm gonna spend my pain & suffering reward right now!! Anyone have contact info for Saul Goodman??
 
I do not know of any typical gearbox, that you just dont fill to the level of "dribble" out of the fill hole, and call it good.

The illustration sucks.
 
GM called for something like 5/8" below the hole on modern-ish 10 bolts.

There's quite a bit of anecdotal experience of noises being quieted by simply filling it all the way. That said, I'm not aware of anything "scientific" regarding this.
 
GM called for something like 5/8" below the hole on modern-ish 10 bolts.

There's quite a bit of anecdotal experience of noises being quieted by simply filling it all the way. That said, I'm not aware of anything "scientific" regarding this.
Right, they call out whatever they want, 100 million rear ends have been filled until dribble and not failed.

I think it has to do with the angle the gear tooth enters the pool of oil, and how well it can be slung without creating void. (bubbles). But I am not scientist either.....not that smart.
 
Right, they call out whatever they want, 100 million rear ends have been filled until dribble and not failed.

I think it has to do with the angle the gear tooth enters the pool of oil, and how well it can be slung without creating void. (bubbles). But I am not scientist either.....not that smart.
Agreed. Banks has the cool vids with clear plastic covers that kinda show how overall oil flow might change with different (aftermarket) covers, but that doesn't really speak to fluid level.

Still it helps show how splash lube works in a diff.
 
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