Differential Pinion seals weeping?

[AusGreenGren]

OK Thanks for the info - will bear that in mind.
I got a response from the (Queensland Australia) dealer this morning - see below for what its worth
Might be something to check in any case -

 

[Clark Kent]

OK Thanks for the info - will bear that in mind.
I got a response from the (Queensland Australia) dealer this morning - see below for what its worth
Might be something to check in any case -


View attachment 7900352

@NQ94 contributed over in the diff breathers thread here that the diff input seal may be a cassette type. You can see in the example seal he posted there are several (5) seal lips that need to be lubricated during operation. Someone else speculated in that thread that the housing breather might maintain a low pressure to (keep water out plus) ensure some oil/mist is pushed past the seal to ensure adequate lubrication. That accords with what your agent is saying. The weeping would appear excessive if the breather is blocked or out of spec. It's a cheap low tech ball and spring device.
The problem is, how much weeping is normal for this seal type and are we accustomed to assessing leakage rates for conventional single or double lip pinion seals that run on the yoke sleeve and tend to only weep when they're starting to fail?
I'd love to hear from a Carraro rep on this, or even an experienced Iveco guy who doesn't have a brand to defend.

Edit: tipos typus typos

 

[TasRingk]

OK Thanks for the info - will bear that in mind.
I got a response from the (Queensland Australia) dealer this morning - see below for what its worth
Might be something to check in any case -


View attachment 7900352

Hi Steve,

I dropped mine off yesterday to have leaking seals looked at whilst they fixed some other warranty issues.
They replaced both pinion seals. Seems strange that back water Launceston dealer with probably <20 vehicles in total to service had them in stock and Brisbane dealer didnt!! In saying that though I had to wait 2 weeks for a thermostat to be sent from Sydney

Cheers
Chris

 

[Brandtnm]

So after having the dealer replace the front differential pinion seals mine appears to be weeping again!

Ffs!

I was under the car today changing the engine oil and saw and smelt the difference fluid in the same lower spot.

Have ragged it clean and will check it frequently and speak to the dealer again.

Note I have fitted neutral raised breathers into the engine bay for both front and rear diffs. Rear one not had a problem. Second time weeping with the front. Once with OEM breather and now again after replacing it with 8mm pipe. Makes me think this is not a pressure problem.

No water crossings or deep puddles since dealer replaced it 3 weeks back.

I look forward to seeing what you find out. I too have weeping, but not enough to cause measurable loss, or generate a drip. I bought, but have not installed, the long breathers. I have found pressure build up under the factory breathers when I checked after big altitude changes (6k’-11k’). I was hoping the pressure and weeping were related. Keep us updated please

 

[Mike Morrison]

Did a bit of gravel travel yesterday, quick look underneath today only to find the front pinion seal leaking.
Vehicle is 2 months old, stock suspension and tyres and the dealer is 8hs away!

 

[Asnes]

Pressure building up in the diff will cause them to leak. Mine were leaking. Installed diff breathers from agile (arb product) and no more problems.

 

[Tenac]

Pressure building the diff will cause them to leak. Mine were leaking. Installed diff breathers from agile (arb product) and no more problems.

Same

 

[Grey Wolf]

Front diff, 2023 model , stock, 14000 miles. Slight leak, not enough to show on the driveway. Hopefully it will be fixed at year 2 service in August.

 

[Mike Morrison]

Pressure building the diff will cause them to leak. Mine were leaking. Installed diff breathers from agile (arb product) and no more problems.

On the to do list. Just figured I’d get more than 3000km before it started weeping, and haven't even been off road yet.

 

[Asnes]

On the to do list. Just figured I’d get more than 3000km before it started weeping, and haven't even been off road yet.

Heat + crummy relief valve….

 

[Asnes]

Uhg! My front pinon seal was replaced about 2 weeks ago. Less than 500 miles later leaking worse than before

Back to the dealer…

 

[abbeyroad]

Pressure building up in the diff will cause them to leak. Mine were leaking. Installed diff breathers from agile (arb product) and no more problems.

Uhg! My front pinon seal was replaced about 2 weeks ago. Less than 500 miles later leaking worse than before

Back to the dealer…

The diff breathers didn't really make a diff?

 

[Asnes]

The diff breathers didn't really make a diff?

So as it turns out, when they replaced the front pinion seal the first time under warrantee, they slightly pinched it somehow on install, which caused the leak. They replaced the seal again (cost was on the dealer, not ineos) and no problems 3,000 miles later.

Rear seal had stop leaking when I had the front done, so it was left alone. So perhaps diff breathers are working.....

 

[Logsplitter]

I’m looking to add raised diff breathers to my Grenadier but still trying to mull over the Ineos design. I understand the original breathers are designed to maintain a certain pressure in the diff, only low pressure maybe 2-4 psi. Does this pressure help to keep water and other contaminants out ? And if so what negative effects would putting a raised breather in for each diff that doesn’t maintain any pressure in the diff have ? I understand from this forum that weeping axle input shaft seals are being attributed to blocked OEM breathers, but some have had input shaft seals fail after they have fitted raised axle breathers.
For those that have put raised breathers on, what fitting have you used at the axle end. The OEM fitting I think is a 10mm x 1 looks like a tapered fitting, but I can’t find any barbed 10mm fittings with a tapered thread online that I would need to fit the breather hose .

 

[Dokatd]

I’m looking to add raised diff breathers to my Grenadier but still trying to mull over the Ineos design. I understand the original breathers are designed to maintain a certain pressure in the diff, only low pressure maybe 2-4 psi. Does this pressure help to keep water and other contaminants out ? And if so what negative effects would putting a raised breather in for each diff that doesn’t maintain any pressure in the diff have ? I understand from this forum that weeping axle input shaft seals are being attributed to blocked OEM breathers, but some have had input shaft seals fail after they have fitted raised axle breathers.
For those that have put raised breathers on, what fitting have you used at the axle end. The OEM fitting I think is a 10mm x 1 looks like a tapered fitting, but I can’t find any barbed 10mm fittings with a tapered thread online that I would need to fit the breather hose . View attachment 7908006

One of my trucks with a more complex air system applies a few PSI to the differential, portals and even the transmission when there is a chance of fording. Otherwise it switches over to atmospheric. It's common to get portal leaks due to wearing seals and maybe just a touch too much pressure. I like many have disabled the system by dropping the regulator down to 0psi. No more leaks! If you ford a river you are fine, if you're going to park in a lake you will want some pressure.

 

[AWo]

They should maintain a certain pressure in the axle?
Sure?
Who wants to haver over or under pressure? Both of them is not good?
A breather should just be an open pipe so that the pressure in the axle is always the same as the ambient pressure.

AWo

 

[Logsplitter]

They should maintain a certain pressure in the axle?
Sure?
Who wants to haver over or under pressure? Both of them is not good?
A breather should just be an open pipe so that the pressure in the axle is always the same as the ambient pressure.

AWo

Thankyou. So why do those breathers on the Grenadier seem to maintain a small pressure. If after using the Grenadier you go under the vehicle, you can let pressure out of those standard breathers.

 

[DaneJa]

I’m looking to add raised diff breathers to my Grenadier but still trying to mull over the Ineos design. I understand the original breathers are designed to maintain a certain pressure in the diff, only low pressure maybe 2-4 psi. Does this pressure help to keep water and other contaminants out ? And if so what negative effects would putting a raised breather in for each diff that doesn’t maintain any pressure in the diff have ? I understand from this forum that weeping axle input shaft seals are being attributed to blocked OEM breathers, but some have had input shaft seals fail after they have fitted raised axle breathers.
For those that have put raised breathers on, what fitting have you used at the axle end. The OEM fitting I think is a 10mm x 1 looks like a tapered fitting, but I can’t find any barbed 10mm fittings with a tapered thread online that I would need to fit the breather hose . View attachment 7908006

I fitted the ARB breather kit that Agile Offroad sells. I imagine it's the same as you'd get straight from ARB other than the mounting bracket under the hood, though it should be easy enough to fab something up for that.

I didn't post much about it since it's pretty standard stuff, but I briefly mentioned the installation at the bottom of this post:

Build Thread Post in thread 'The Lobster, DaneJa's overlanding build'

Jun 29, 2025

I've been a bit slow to update this thread, but I haven't been totally idle.

@ColoradoMike and I worked together to get our Owl Vans Pro-Line Skid Plates installed. I won't rehash my review of the skids, but suffice it to say they are very nice but it was a long day of work to get them installed. More about our experience with the skids here. I'll throw some additional images from the install here.

Removing the OEM tank skid and cross-brace was trivial.

I trimmed the bolts in the middle section of the new cross-brace that...

• DaneJa

• 

 

[Logsplitter]

I fitted the ARB breather kit that Agile Offroad sells. I imagine it's the same as you'd get straight from ARB other than the mounting bracket under the hood, though it should be easy enough to fab something up for that.

I didn't post much about it since it's pretty standard stuff, but I briefly mentioned the installation at the bottom of this post:

Build Thread Post in thread 'The Lobster, DaneJa's overlanding build'

Jun 29, 2025

I've been a bit slow to update this thread, but I haven't been totally idle.

@ColoradoMike and I worked together to get our Owl Vans Pro-Line Skid Plates installed. I won't rehash my review of the skids, but suffice it to say they are very nice but it was a long day of work to get them installed. More about our experience with the skids here. I'll throw some additional images from the install here.

Removing the OEM tank skid and cross-brace was trivial.

I trimmed the bolts in the middle section of the new cross-brace that...

• DaneJa

• 

Thanks. Can you confirm if the axle fittings are m10 x 1 as all the ARB kits available in the UK have 1/8bsp fittings. I can easily order some m10 x 1 fittings separately

 

[AWo]

Thankyou. So why do those breathers on the Grenadier seem to maintain a small pressure. If after using the Grenadier you go under the vehicle, you can let pressure out of those standard breathers.

I don't know...
I could imagine that when they are clogged, air can't leave and then you end up with pressure.

The thing is, that it was tried in the past to put axles actively under pressure to keep water out, which led to oil being pressed out.

Two years ago in Ireland we found the front differential pinion seal leaking. It was a bend breather pipe. Fixed that, leaking stopped.

AWo