Front differential, rear differential, and transfer case fluid levels

[scottg]

Just adjusting your caster will change all of this I'm going to try to hold my tongue on this thread as best I can.

Fill to spill and be done with it. Stop nuking everything. I would put money on it your dealer fills to spill regardless of anything Ineos publishes.

I was a Land Rover tech and I guarantee had they come out with some BS like this we would have all ignored it. Mechanics move fast and we wouldn't waste time on something so inconsequential.

And don't get me started on torquing every bolt to spec. I've seen some crazy stuff in the mechanic world.

I would love to just "fill and spill" and be done with it. And then this happens:

ME: "Hi, my rear differential is grinding badly."

INEOS Dealer: "We checked the fluid level, then took it apart, it's toast. We've contacted INEOS to determine if this is a warranty repair/replacement."

INEOS: "The differential fluid was not filled to spec, it was overfilled. Sorry, no warranty coverage for this."

Saying that dealer mechanics would and do fill and spill and overfill the differentials isn't a defense that would be accepted if I were denied warranty coverage for doing that same thing. IA would probably service it under warranty, but there is no guarantee of that and I prefer not to risk it.

We can and do beat dead horses in many discussions, but I disagree with the characterization that we're "nuking" everything. Until I'm out of warranty, I want to DIY service to INEOS spec, but when I can't find the official IA spec for things, it's reasonable to ask and to ask for sources, esp. when the answers provided differ. So I'll be asking.

/s.

 

[Tenac]

I would love to just "fill and spill" and be done with it. And then this happens:

ME: "Hi, my rear differential is grinding badly."

INEOS Dealer: "We checked the fluid level, then took it apart, it's toast. We've contacted INEOS to determine if this is a warranty repair/replacement."

INEOS: "The differential fluid was not filled to spec, it was overfilled. Sorry, no warranty coverage for this."

Saying that dealer mechanics would and do fill and spill and overfill the differentials isn't a defense that would be accepted if I were denied warranty coverage for doing that same thing. IA would probably service it under warranty, but there is no guarantee of that and I prefer not to risk it.

We can and do beat dead horses in many discussions, but I disagree with the characterization that we're "nuking" everything. Until I'm out of warranty, I want to DIY service to INEOS spec, but when I can't find the official IA spec for things, it's reasonable to ask and to ask for sources, esp. when the answers provided differ. So I'll be asking.

/s.

My tech told me they do exactly that fill and spill. I'm not sure Ineos would be willing to prove that a few extra ounces would cause a diff to break into pieces. I could be wrong I do not design or engineer diffs but would assume the real issue would be spill via the bleeder valves if any.

 

[Dokatd]

I would love to just "fill and spill" and be done with it. And then this happens:

ME: "Hi, my rear differential is grinding badly."

INEOS Dealer: "We checked the fluid level, then took it apart, it's toast. We've contacted INEOS to determine if this is a warranty repair/replacement."

INEOS: "The differential fluid was not filled to spec, it was overfilled. Sorry, no warranty coverage for this."

Saying that dealer mechanics would and do fill and spill and overfill the differentials isn't a defense that would be accepted if I were denied warranty coverage for doing that same thing. IA would probably service it under warranty, but there is no guarantee of that and I prefer not to risk it.

We can and do beat dead horses in many discussions, but I disagree with the characterization that we're "nuking" everything. Until I'm out of warranty, I want to DIY service to INEOS spec, but when I can't find the official IA spec for things, it's reasonable to ask and to ask for sources, esp. when the answers provided differ. So I'll be asking.

/s.

You are literally nuking it in this post. First of all there is no possible way filling to the port will cause mechanical failure on these axles. Second you are assuming a tech will check the fluid level. Well, I've got news for you, this is not NASA. The tech will drain the oil into a catch basin full of oil from other trucks. They will look for glitter while they do it at best. The techs don't have the time or patience to use a graduated cylinder to measure the oil coming out of your diff. Nor do they give a damn, it's not their money. They want to turn tickets as fast as possible with as few call backs as possible.

I feel like I am taking crazy pills here, y'all are still using some hand made document out of Africa and saying it's the bible. And oil capacities are not meant to be followed to the T. Oil capacities on these types of vehicles are meant to tell you about what you will need, not what you need precisely.

I mean seriously, if these trucks are such delicate little flowers that an 1/8th of a quart more oil in the diff will blow it up then to hell with the Grenadier and Ineos.

Seriously y'all need to find something better to use your brain power on. And I probably do too, because too many of you guys are lost causes. Literally, the brain power on this forum is incredible, but as it always seems to be, the smartest group of people often can't figure out the simplest things.

Ok, I am ranting and don't overly want to. Time to head off to my office/shop and work on some trucks for a little bit.

 

[scottg]

You are literally nuking it in this post. First of all there is no possible way filling to the port will cause mechanical failure on these axles. Second you are assuming a tech will check the fluid level. Well, I've got news for you, this is not NASA. The tech will drain the oil into a catch basin full of oil from other trucks. They will look for glitter while they do it at best. The techs don't have the time or patience to use a graduated cylinder to measure the oil coming out of your diff. Nor do they give a damn, it's not their money. They want to turn tickets as fast as possible with as few call backs as possible.

I feel like I am taking crazy pills here, y'all are still using some hand made document out of Africa and saying it's the bible. And oil capacities are not meant to be followed to the T. Oil capacities on these types of vehicles are meant to tell you about what you will need, not what you need precisely.

I mean seriously, if these trucks are such delicate little flowers that an 1/8th of a quart more oil in the diff will blow it up then to hell with the Grenadier and Ineos.

Seriously y'all need to find something better to use your brain power on. And I probably do too, because too many of you guys are lost causes. Literally, the brain power on this forum is incredible, but as it always seems to be, the smartest group of people often can't figure out the simplest things.

Ok, I am ranting and don't overly want to. Time to head off to my office/shop and work on some trucks for a little bit.

Thanks for the input, Dokatd, I'll shut up now.

 

[Dokatd]

Thanks for the input, Dokatd, I'll shut up now.

To be clear, I love the conversation and certainly banter. But I dislike seeing people make life harder on themselves and or take things out of context. I'm not sure why I care so much but I truly do. Spend your time and clear brain power on things that mean something at the end of the day.

Sometime engineering specs are just there to check a box. Go find another more fun box to check.

But yeah I understand some people get off on checking each box precisely and feel that's meaningful. And if that's you or anyone else here I don't mean to be an ass. But I suspect most of us bought these trucks to drive not work on them. If working on them was the goal then an older 90's Defender is a far better place to spend time.

An aside to this, I love the old guys that volunteer at the aviation museums. The ones that tinker on the same part or plane for years making everything just so. I have such respect for those guys, especially since I myself fly and maintain what's realistically an antique nowadays. But the way I see it those guys are maintaining the past and they have lived the glory days of operating the machines they diligently maintain and preserve today.

 

[Glen]

You are literally nuking it in this post. First of all there is no possible way filling to the port will cause mechanical failure on these axles. Second you are assuming a tech will check the fluid level. Well, I've got news for you, this is not NASA. The tech will drain the oil into a catch basin full of oil from other trucks. They will look for glitter while they do it at best. The techs don't have the time or patience to use a graduated cylinder to measure the oil coming out of your diff. Nor do they give a damn, it's not their money. They want to turn tickets as fast as possible with as few call backs as possible.

I feel like I am taking crazy pills here, y'all are still using some hand made document out of Africa and saying it's the bible. And oil capacities are not meant to be followed to the T. Oil capacities on these types of vehicles are meant to tell you about what you will need, not what you need precisely.

I mean seriously, if these trucks are such delicate little flowers that an 1/8th of a quart more oil in the diff will blow it up then to hell with the Grenadier and Ineos.

Seriously y'all need to find something better to use your brain power on. And I probably do too, because too many of you guys are lost causes. Literally, the brain power on this forum is incredible, but as it always seems to be, the smartest group of people often can't figure out the simplest things.

Ok, I am ranting and don't overly want to. Time to head off to my office/shop and work on some trucks for a little bit.

I'm not really sure what "nuking it" means . . . must be some Gen X slang I'm not hip to.

As far as a "handmade document out of Africa goes," I guess that's your feeble attempt to show your contempt for someone not in your tribe. You should do better.

With respect to an authority on the matter, this post appears to publish an Ineos service document, and I'd say that's a pretty good authority.

One of the great advantages of being a human - compared to say, a computer program - is that we can adapt to changing circumstances in light of new information. Sure, I've filled diffs up to the fill plug for my whole life, but if I get new, credible information, it seems like a no-brainer to adapt and change my behavior. Kicking and screaming and calling people names doesn't seem like a resonable way to deal with that new information.

For those still mulling it over, here is a hypothesis (an unproven conjecture) that is an example of how Ineos could have gotten to the point where they decided to specify a differential fill level below the fill plug:
1) Carraro is asked to design and supply an axle for the Grenadier. This axle comes with a fill plug that corresponds to a lubrication level that has worked in past applications, including tractors and off-road vehicles.
2) During offroad testing that involved extreme angles , Ineos observed fluid leaving the differential housing via the vent. Alternately or additionally, Ineos detected differential oil foaming during extended high speed highway operation.
3) Ineos techs asked Carraro if reducing the fluid level in the differential to 2.1 liters would have an adverse effect on the operation or longevity of the differential. Carraro replied it would not have any adverse effects.
4) Ineos adopted a specification of 2.1 liters differential fluid to avoid loss of fluid during extreme offroad operations and / or during extended high speed highway operations.

Remember @Dokatd , you can always look away if a conversation bothers you so much that you have to resort to insults.

Cheers.

 

[Dokatd]

I'm not really sure what "nuking it" means . . . must be some Gen X slang I'm not hip to.

As far as a "handmade document out of Africa goes," I guess that's your feeble attempt to show your contempt for someone not in your tribe. You should do better.

Nuking refers to over cooking it or rather over thinking it. Not my favorite term but lots of people like to use it.

The document in question posted by log splitter in this thread is literally something cobbled together by a remote dealer in Africa or similar. I don't recall the exact location that made the document. This has already been discussed prior. It was admitted to be something the local shop came up with for their techs and not from Ineos themselves. The true source is as of yet unverified.

 

[Glen]

Nuking refers to over cooking it or rather over thinking it. Not my favorite term but lots of people like to use it.

The document in question posted by log splitter in this thread is literally something cobbled together by a remote dealer in Africa or similar. I don't recall the exact location that made the document. This has already been discussed prior. It was admitted to be something the local shop came up with for their techs and not from Ineos themselves. The true source is as of yet unverified.

Okay. Are you disputing the accuracy of this document?

E

Post in thread 'Changing the Differential Fluid'

Aug 19, 2025

This is what the service manual recommends. It says to fill with a max volume of 2.1L of diff oil.

• etbandit

• 

 

[Logsplitter]

Nuking refers to over cooking it or rather over thinking it. Not my favorite term but lots of people like to use it.

The document in question posted by log splitter in this thread is literally something cobbled together by a remote dealer in Africa or similar. I don't recall the exact location that made the document. This has already been discussed prior. It was admitted to be something the local shop came up with for their techs and not from Ineos themselves. The true source is as of yet unverified.

The document came from Cpmpass Automotive and the tech at Ineos HQ in Cape Town used the same method.
Has it been considered that the oil amount of 2.1L is correct for the application but the filler plug is too high for the application, because the axle was designed for other applications originally with a higher fill level.

 

[Dokatd]

Okay. Are you disputing the accuracy of this document?

E

Post in thread 'Changing the Differential Fluid'

Aug 19, 2025

This is what the service manual recommends. It says to fill with a max volume of 2.1L of diff oil.

• etbandit

• 

No, I'm talking about the document with the Allen wrench measuring tool. To be fair the document you post does say SSTxxx. But what is that and why do the local dealers not have or use it.

The document you posted has to have a qty on it for legal purposes. This qty has to be plus or minus within a margin also for legal purposes.

But what happens when you change caster of the front axle? The rear axle pinion angle is also adjustable. What happens when Ineos fails to set these correctly. This has been a documented problem not a hypothetical. The Allen tool dipstick assumes everyone's axle is set to the same spec and is sitting on a dead nuts perfectly flat surface. It's also assuming the truck is not lifted and has perfectly set tire pressures. All these things make a difference when compounded. And the reality is they all affect the fill to spill method too.

My point is the dipstick measuring method is coming from a non sanctioned body to the best of our knowledge, and if you put 2, 2.1 or 2.3 liters in your diff you won't cause any damage whatsoever. .1 liters is just shy of 7 table spoons. That's a drop in the bucket and unmeasurable in practical applications.

It's panicking people into thinking their warranty is going to be void if they don't get it just so. Me coming from having been a Land Rover mechanic I can tell you with certainty nobody will have the foggiest idea how much was in there unless it was dramatically too little or comes flowing out like Niagra falls.

Thus this is being Nuked

 

[Dokatd]

The document came from Cpmpass Automotive and the tech at Ineos HQ in Cape Town used the same method.
Has it been considered that the oil amount of 2.1L is correct for the application but the filler plug is too high for the application, because the axle was designed for other applications originally with a higher fill level.

That would 100% require a service notice sent to every service center for correction. We already have others reporting their Ineos dealer fills to spill. The industry standard is fill to spill right or wrong. So Ineos could not let that go if it had the possibility of causing failures. Ineos could not rely on the calibration of oil pumps at the varied service centers across the world to hit 2.1. And they damn sure wouldn't publish public service manuals without warning of the exact level of not qty. Qty of oil is not a substitute for exact level. Qty of oil cannot account for errors in draining methods or simply a mismeasured amount of oil.

 

[C-Mack]

I would think they could easily switch out the axle differential cover plates and change the fill port height based on specific applications if the fill port is intended to be the true fill level indicator.

Just go with the 2.1L total amounts as this would likely have been somewhat calculated to make sure sufficient fluid is in the axle regardless of whatever angle the axle is sitting at during drain/fill service. A slight overfill of .1 or .2L is not going to hurt anything where as gross overfilling would not be good.

Now if the fill ports were the true fill level and you didn’t level the vehicle perfectly and were on a bit of slope I could see one of the diffs being slightly over filled and other under filled. I actually like there is bit of head space between the fluid level and fill port and they tell you the target fluid amount as it’s less critical to get the vehicle perfectly level. So basically if you measure out 2.1L and mange to get it all in you should be good to go. Then for extra piece of mind do the little dipstick check if you must.

 

[Logsplitter]

That would 100% require a service notice sent to every service center for correction. We already have others reporting their Ineos dealer fills to spill. The industry standard is fill to spill right or wrong. So Ineos could not let that go if it had the possibility of causing failures. Ineos could not rely on the calibration of oil pumps at the varied service centers across the world to hit 2.1. And they damn sure wouldn't publish public service manuals without warning of the exact level of not qty. Qty of oil is not a substitute for exact level. Qty of oil cannot account for errors in draining methods or simply a mismeasured amount of oil.

I get what you’re saying, and I’m not claiming to be a tech or an engineer here.
I’m also not saying that filling to spill is suddenly dangerous, or that being a bit over or under 2.1 L is going to cause a failure. I agree that in the real world diffs are pretty tolerant.
My point is much simpler than that. INEOS have published a quantity-based figure for this vehicle, and that’s the only reason some of us are paying attention to it — especially while under warranty.
Dealers filling to spill doesn’t surprise me at all. That’s how most of us have done diffs for years. But dealer habit and written spec aren’t always the same thing, and if something ever did go wrong, it’s the written spec that matters, not what’s “usually done”.
I’m not panicking, and I’m not telling anyone how to service their own truck. I’m just saying that if someone wants the lowest-risk approach during warranty, following what INEOS have actually written down seems reasonable.
If INEOS come out and say “fill to spill is fine” or issue a service note clarifying it, that ends the discussion instantly.

 

[Logsplitter]

Just to add, I’m not saying the Allen key thing is some super accurate measuring tool.
All I mean is that if you actually put 2.1 L in that method does line up . So it’s not random or made up, it does correlate with the quoted volume.
Does that mean small differences suddenly matter? No. And I’m not saying fill to spill is wrong either. Just that the method and the number INEOS give do seem to match up in practice.
That’s all I’m getting at really.

 

[Tazzieman]

Just to add, I’m not saying the Allen key thing is some super accurate measuring tool.
All I mean is that if you actually put 2.1 L in that method does line up . So it’s not random or made up, it does correlate with the quoted volume.
Does that mean small differences suddenly matter? No. And I’m not saying fill to spill is wrong either. Just that the method and the number INEOS give do seem to match up in practice.
That’s all I’m getting at really.

It's OK with me; I'm not going to start calling you names like Hairsplitter
Nor Tool. That one is reserved

 

[Dokatd]

I get what you’re saying, and I’m not claiming to be a tech or an engineer here.
I’m also not saying that filling to spill is suddenly dangerous, or that being a bit over or under 2.1 L is going to cause a failure. I agree that in the real world diffs are pretty tolerant.
My point is much simpler than that. INEOS have published a quantity-based figure for this vehicle, and that’s the only reason some of us are paying attention to it — especially while under warranty.
Dealers filling to spill doesn’t surprise me at all. That’s how most of us have done diffs for years. But dealer habit and written spec aren’t always the same thing, and if something ever did go wrong, it’s the written spec that matters, not what’s “usually done”.
I’m not panicking, and I’m not telling anyone how to service their own truck. I’m just saying that if someone wants the lowest-risk approach during warranty, following what INEOS have actually written down seems reasonable.
If INEOS come out and say “fill to spill is fine” or issue a service note clarifying it, that ends the discussion instantly.

I gotcha, and that's a level headed response if I have ever seen one. I think we largely agree. But the one point I will make, every manufacturer regardless of fill method will publish a fluid qty to the 10th of a liter or similar. So Ineos is not doing something special here.

 

[Tazzieman]

Chances are your anaesthetist (or anasthesiologist to use an unecessarily long word) will look you up and down and think yeah, big fella, I'll just whack an extra half syringeful of paralysing fluid in. That should do it. What's the worst that can happen?
(These things happen btw)

 

[Dokatd]

Just to add, I’m not saying the Allen key thing is some super accurate measuring tool.
All I mean is that if you actually put 2.1 L in that method does line up . So it’s not random or made up, it does correlate with the quoted volume.
Does that mean small differences suddenly matter? No. And I’m not saying fill to spill is wrong either. Just that the method and the number INEOS give do seem to match up in practice.
That’s all I’m getting at really.

Fair enough, but I will say again that qty is an insanely inaccurate way of filling anything that gets its fluids changed. Spillage, surface tension, poor calibration or simply misreading graduations can easily lead to under or over filling. I understand that the Allen wrench dip stick cures that to an extent of course. But that sure makes for a very unfriendly vehicle to take into the wilds of the world. But hey we are finding that the case almost daily with our Grenadiers it seems.

And to be fair how many transmissions dip sticks require the engine to be running or not to get a proper reading, seems like they are all different. You certainly do have to know your vehicle to properly work on it.

 

[Dokatd]

Chances are your anaesthetist (or anasthesiologist to use an unecessarily long word) will look you up and down and think yeah, big fella, I'll just whack an extra half syringeful of paralysing fluid in. That should do it. What's the worst that can happen?
(These things happen btw)

Just don't be a Ginger from what I hear.

 

[Tazzieman]

Just don't be a Ginger from what I hear.

Btw I realised I spelt anesthesiologist wrongly in my previous post. At least I didn't spell it anaesthesiologist. That would be 1.06 out. I think.