Changing the Differential Fluid

[255/85]

If thats the case what is the difference between 2.1 L and fill to spill??

At the widest part of the housing the 23mm difference could be a lot.

i think you're overthinking it. Telling people to fill until it runs out, isn't environmental conscious.

It's the lawyers' responsibility to specify "only to the the bottom edge of the fill opening" or 1/8" below, etc. No company in their right mind would instruct an end user to stuff it in there until it oozes out. We may be able to but, for the warranty period, I'll elect to follow the specs.

See where the oil level is in relation to the axle shafts are in the housing. They're likely keeping the oil level below the drive axle in the axle housing as the axle doesn't need to be in an oil bath. Looking at the diagram the fill plug is above the axles

What about the axle shaft seals? they'd need a little but constant lubrication. Kinda shoots my theory down.

 

[Zimm]

At the widest part of the housing the 23mm difference could be a lot.



It's the lawyers' responsibility to specify "only to the the bottom edge of the fill opening" or 1/8" below, etc. No company in their right mind would instruct an end user to stuff it in there until it oozes out. We may be able to but, for the warranty period, I'll elect to follow the specs.



What about the axle shaft seals? they'd need a little but constant lubrication. Kinda shoots my theory down.

The widest part of the housing up to the fill hole also happens to be where the mechanical bits occupying space flinging the fluid are located. A ford 10.25 is a much larger unit than this. it takes 3.5l per spec, but will not take more than 4l without spilling.

What would the lawyers be worried about?

I'm not telling you not to follow the specs, feel free. I'm saying any consternation about filling to the bung, is completely unwarranted and a special tool is kinda funny.

 

[255/85]

What would the lawyers be worried about?

The spilling, silly.

I'm not telling you not to follow the specs, feel free. I'm saying any consternation about filling to the bung, is completely unwarranted and a special tool is kinda funny.

In truth I'm not too worried but I also don't want to be the one that has fingers pointed in his direction when someone else's warranty is voided from following my advice. I have an aversion to authority... including my own.

It did only take roughly a half quart of extra fluid to overfill the D44 that I mentioned before. Not pretty but maybe not catastrophic.

 

[NQ94]

At the widest part of the housing the 23mm difference could be a lot.



It's the lawyers' responsibility to specify "only to the the bottom edge of the fill opening" or 1/8" below, etc. No company in their right mind would instruct an end user to stuff it in there until it oozes out. We may be able to but, for the warranty period, I'll elect to follow the specs.



What about the axle shaft seals? they'd need a little but constant lubrication. Kinda shoots my theory down.

There will be oil and splash in the axle tubes but the level below the axle shafts means that the axle isn't constantly churning in the oil. Similar to how truck axles lubricate wheel bearings. Most of the truck axles like Meritor and Dana manuals say fill to spill.

 

[Tom109]

No company in their right mind would instruct an end user to stuff it in there until it oozes out.

But that is how it has traditionally been done, and directly relevant for 50+ years.

 

[Dokatd]

But that is how it has traditionally been done, and directly relevant for 50+ years.

Different times my friend.

 

[Logsplitter]

Right here is the definitive answer on the diff oil debate from Ineos Automotive themselves. So don’t fill to overflow.

 

[Tom109]

Different times my friend.

And the de-evolution of Engineering. Just lower the fill hole you idiot!

 

[Tom109]

Right here is the definitive answer on the diff oil debate from Ineos Automotive themselves. So don’t fill to overflow.View attachment 7906627View attachment 7906626

Where did this come from?

 

[Logsplitter]

Where did this come from?

An Ineos agent/dealer in the UK. But this is the method the tech used when I was in Cape Town

 

[Dokatd]

Right here is the definitive answer on the diff oil debate from Ineos Automotive themselves. So don’t fill to overflow.View attachment 7906627View attachment 7906626

Who is the grade school author of this doc.

Anyways, we already knew this was the recommendation. And it's still a waste of time and effort. Fill till it drips and move on to the next task.

 

[Logsplitter]

Who is the grade school author of this doc.

Anyways, we already knew this was the recommendation. And it's still a waste of time and effort. Fill till it drips and move on to the next task.

Some people care about the recommended method of measuring the diff oil and not everybody knows that this was the recommended method. If you don’t like the thread then move on and ignore it I suggest.

 

[CountyV8]

It looks like a Wera Allen key would other makes do.
Think before answering.

 

[Dokatd]

Some people care about the recommended method of measuring the diff oil and not everybody knows that this was the recommended method. If you don’t like the thread then move on and ignore it I suggest.

Can't ignore everything you find distasteful. .

But that doc is a bit embarrassing if it really came from Ineos.

 

[Logsplitter]

Can't ignore everything you find distasteful. .

But that doc is a bit embarrassing if it really came from Ineos.

It could have been a locally produced document by an agent or tech somewhere, as I know the techs in Southern Africa were using this method. This then spread around from there maybe. . Some agents I’m aware of weren’t aware of any method other than fill to bottom of fill hole anyway. The method and measurements seem correct to me though as I was sent this document from my U.K. dealer. If Ineos are putting in 2.1L from factory and @Greasemonkey could get in around 3L on the fill to overflow method when he was experimenting with diff oil levels , then there must be a valid reason why they are putting in 2.1L. We need an answer Ineos automotive HQ themselves I guess to understand why. Maybe another tech on this forum can elaborate ?

 

[landmannnn]

It could have been a locally produced document by an agent or tech somewhere, as I know the techs in Southern Africa were using this method. This then spread around from there maybe. . Some agents I’m aware of weren’t aware of any method other than fill to bottom of fill hole anyway. The method and measurements seem correct to me though as I was sent this document from my U.K. dealer. If Ineos are putting in 2.1L from factory and @Greasemonkey could get in around 3L on the fill to overflow method when he was experimenting with diff oil levels , then there must be a valid reason why they are putting in 2.1L. We need an answer Ineos automotive HQ themselves I guess to understand why. Maybe another tech on this forum can elaborate ?

Not claiming to be a tech.

As a general rule* you don't want any seals for a shaft to be permanently submerged in oil. There is a potential to have a leak or at least seepage if the vehicle or piece of machinery is sat unused for long periods holding back the oil. It is the same with the crankshaft oil seals on the engine for example.

You do need lubrication, but there is enough splash lubrication to take care of that.

Looking at the axles I think the resting oil level is slightly below the level of the three seal lips per axle.

* rule is probably the wrong word, I couldn't think of anything better.

That doesn't answer the question of why the fill hole isn't a bit lower.

 

[NQ94]

Not claiming to be a tech.

As a general rule* you don't want any seals for a shaft to be permanently submerged in oil. There is a potential to have a leak or at least seepage if the vehicle or piece of machinery is sat unused for long periods holding back the oil. It is the same with the crankshaft oil seals on the engine for example.

You do need lubrication, but there is enough splash lubrication to take care of that.

Looking at the axles I think the resting oil level is slightly below the level of the three seal lips per axle.

* rule is probably the wrong word, I couldn't think of anything better.

That doesn't answer the question of why the fill hole isn't a bit lower.

If it's got any type of seal or gasket irrespective of the fluid, gas or pressure or if the seal is submerged in oil, a dynamic seal or a simple gasket there is always the potential for excessive leakage. Sometimes it's just the luck of the draw.

 

[Dokatd]

Not claiming to be a tech.

As a general rule* you don't want any seals for a shaft to be permanently submerged in oil. There is a potential to have a leak or at least seepage if the vehicle or piece of machinery is sat unused for long periods holding back the oil. It is the same with the crankshaft oil seals on the engine for example.

You do need lubrication, but there is enough splash lubrication to take care of that.

Looking at the axles I think the resting oil level is slightly below the level of the three seal lips per axle.

* rule is probably the wrong word, I couldn't think of anything better.

That doesn't answer the question of why the fill hole isn't a bit lower.

Well, there are a whole lot of shaft seals out there that should be leaking then.

Engineers of autos are not designing for vehicles to sit for years or decades without service. They are not designing for the guy that has a really steep driveway. They are not designing for areas of the world that have significant road crown. They design to retain oil at max head pressures. They also have to account for external pressure such as when fording.

There is a lot going on when designing a vehicle, they do their best and improve as the design matures.

 

[Dokatd]

It could have been a locally produced document by an agent or tech somewhere, as I know the techs in Southern Africa were using this method. This then spread around from there maybe. . Some agents I’m aware of weren’t aware of any method other than fill to bottom of fill hole anyway. The method and measurements seem correct to me though as I was sent this document from my U.K. dealer.

There it is! If you had lead with that it would have had better context and been more forgivable. Now it's just another rumor. Let's get this straight, I'm not saying this isn't the Ineos procedure, I'm just saying it's not as critical as people are making it out to be. I "fill to spill", but I wouldn't top off a diff if its oil level was within reasonable reach of the fill plug hole. Nor would I open another bottle just to make sure oil drips.

Just get it close enough and roll with it. Don't fret over the exact mm's away from a fill hole the oil should be. Some more novice people here might not drive their trucks just because they aren't sure if the oil level is spot on or go get a pump to try to pump out a mm or two because they accidentally "overfilled" the diff. It's just not that critical.

For reference I have been building diffs since the late 90's both for personal use and for client use. First one was my D90 when I changed gears. I have disassembled diffs on dusty rocky trails with trucks siting at 30° angles. Even counting field repairs I have never had a diff failure on a diff I rebuilt. This doesn't discount the Ineos fill method, just that I have experience, likely more than most mechanics currently in the work force as they don't or aren't allowed to rebuild diffs. So I am not COMPLETELY talking out of my ass.

Too be clear, I'm not saying do what I say, I just don't want novices here to be afraid to fill their diff with 2.4litres of fluid. It's not the same as over filling your engine or trans which could be hurt by substantial over filling. The diff level tool is just not necessary and could even be wrong if you don't take in account if the truck is on substantially level ground in any direction.