D3 - front diff breather

[PeterOZ]

Folks,
got oil leak on the front diff and suspect it is the pinion seal. I have read that a blocked front diff breather can cause that due to pressure build up.

I found what was left of my tube last night, it is about level with the bottom of coolant reservoir, no cap on it, looks like the end had been broken off when the engine swap was done about 5 years ago.

If there a way to check if the tube itself has blockages? Not sure if you can get it off the diff itself?

I was going to get the upgraded breather cap as per the TSB.

TIA

cheers
Peter

[scarry]

Blow down it,in situ,you will soon work out whether its blocked.

The D4 had a little filter on the end of it.

[PeterOZ]

Blow down it,in situ,you will soon work out whether its blocked.

The D4 had a little filter on the end of it.

that may be a challenge as what is left is down about level with the bottom of coolant bottle, I'll see if I can pull it out and have a crack.

[DiscoJeffster]

Blow down it,in situ,you will soon work out whether its blocked.

The D4 had a little filter on the end of it.

Where is the air going to go??? As far as I’m aware the diff is a sealed unit (obviously so what doesn’t get in) - the vent is there to avoid pressure or vacuum situations AFAIK.

[PeterOZ]

just found a thread on this forum about the TSB

replacement front diff breather Disco 3 and 4 (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/256850-replacement-front-diff-breather-disco-3-4-a.html)

[scarry]

Where is the air going to go??? As far as I’m aware the diff is a sealed unit (obviously so what doesn’t get in) - the vent is there to avoid pressure or vacuum situations AFAIK.

Done it a hundred times,you will slightly pressurise the diff,then feel the pressure waft back out.
I have done it mainly with vehicles with solid axle,the D4 diff has a smaller volume but it should work the same.
If you are really worried remove the filler plug,then blow through it.

And for Pete,maybe a bit of hose will slide over the remaining hose,making the job easier?

For those with Jap vehicles,there is often a check valve on the end of the diff breather tube that needs to be removed before checking for blockages.

[PeterOZ]

I have ordered the upgraded breather from rimmer bros, in the interim I will put a bit of sponge over the end of the hose to stop crap and or inspects getting in there.

[PerthDisco]

I have ordered the upgraded breather from rimmer bros, in the interim I will put a bit of sponge over the end of the hose to stop crap and or inspects getting in there.

I found one of my garden sprinkler dribblers fitted perfectly and provide insect protection

[PeterOZ]

I found one of my garden sprinkler dribblers fitted perfectly and provide insect protection


will wash the engine bay at same time [biggrin]

[scarry]

will wash the engine bay at same time [biggrin]

And bring up a few fault codes……[bigsad][biggrin]

[Eric SDV6SE]

And bring up a few fault codes……[bigsad][biggrin]

"Washer bottle is empty" would be one

[PeterOZ]

was able to pull enough of the tube out so I could fit another length of clear hose over it and blow down. This is just straight tube with no breather fitted and I found I could blow very little if at all into the tube. Tiny bit of pressure came back out. I have no idea if you should be able to blow pressure into the diff at all??

Anybody know?

Reading the manual for the diff it shows there is a 90 degree fitting that goes on top of the diff and is described as "breather tube and cap" items 34 & 35.

Would either of these be likely to block?
As my back is damn tender at the moment the last thing I feel like doing is crawling about underneath and pulling access cover off etc.

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[Eric SDV6SE]

was able to pull enough of the tube out so I could fit another length of clear hose over it and blow down. This is just straight tube with no breather fitted and I found I could blow very little if at all into the tube. Tiny bit of pressure came back out. I have no idea if you should be able to blow pressure into the diff at all??

Anybody know?

Reading the manual for the diff it shows there is a 90 degree fitting that goes on top of the diff and is described as "breather tube and cap" items 34 & 35.

Would either of these be likely to block?
As my back is damn tender at the moment the last thing I feel like doing is crawling about underneath and pulling access cover off etc.

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Unlikely to block in my view, you should not be able to blow through this breather as this would indicate air is getting past the diff output seals. The 90 deg bend would stop any diff oil travelling up the tube.

[DiscoJeffster]

I would say, as Scarry did above, remove the filler and then try - this way you have somewhere for the air to escape. I agree with Eric, there’s no reason it would get blocked unless you got unlucky and had a critter crawl in and die in there while it was open.

[scarry]

was able to pull enough of the tube out so I could fit another length of clear hose over it and blow down. This is just straight tube with no breather fitted and I found I could blow very little if at all into the tube. Tiny bit of pressure came back out. I have no idea if you should be able to blow pressure into the diff at all??

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It will be clear.Block the end of a meter of tube and blow into it and compare.The D4 diff is a pretty small volume.

There is no way you will be able to blow past the seals,unless they are shagged.

I have come across them blocked,usually a mixture of dirt and oil from what i have seen,or a wasps nest.

We used to find them blocked often on the work vans,but they have a very short breather.
If the diff was on a vacuum when we went to change the oil,as it had cooled down,that was the indicator the breather was blocked.
The diff seals never leaked.