Grey Differential Oil - Oh Ohh!!!

Did a big service on the P38 at the weekend at 120k. When I drained the rear diff it was a lovely clear colour with just a hint of black but looked like I could easily put it back in. Filled it up with new diff oil and on to the next. Sorted!

Went to change the oil on the front diff and what i got out was a horrible milky grey colour and less than a litre (its supposed to be 1.6).
OHH Crap (well what I actually said was a little less polite and is now being repeated by my 2 year old with the appropriate intonation and everything ) says I, with the thought of munched up diff requiring £100's to replace.
Before I panicked I said I'd try and strain the oil to check for bits of metal but couldn't find any.
This got me thinking about all the flooding back along of which I was none too shy about ploughing through. I didn't get a chance to check if the breather pipes are still ok but I will next weekend.

If water got in the diff, what would it look like and more importantly what would it do?
I don't really have any driveline issues at the moment. I get a small clunky click when going form forward to reverse or vice versa but it sounds much more like a cv joint than anything else.

Unless there was a fair amount, I would think you should be ok. As you know, EP90 is very thick and clingy. Bear in mind that a large(ish) amount of water would settle at the bottom of the diff pan when the car has been stood for a while.
To be perfectly sure, you could remove the diff. and clean out the interior of the diff pan before refilling. Alternatively, you could refill with EP80, run the car for say a week, then drain and refill with EP90. The EP80 should hopefully have a "Flushing" effect.
Finally, there must be someone on here who is in to offroading and has had the same issue.
Regarding the breather tubes, there is a good chance that the water got into the axle tubes past the halfshaft seals, maybe it would be prudent to replace these..pig of a job, especially separating the hub from the swivel but otherwise straightforward and inexpensive.:behindsofa:

put some fresh oil in and run it for a few days then check it out.

then sell it...

Beast o Bodmin said:

put some fresh oil in and run it for a few days then check it out.

then sell it...

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That's not how you usually spell 'burn' BoB!

Thanks Irish,

I think you might be right. I've ordered some diff seals from Island 4x4 (I bust the drivers side mirror off a Transit (actually might be truer to say he bust it since I was clung to the ditch on my side but anyway!) in Mayo yesterday so I'm getting the lot from them) so might have a crack at it in a week or so. I'll definitely do the EP80 oil thing this weekend and see how it looks the following week.

Cormac

kooky_guy said:

That's not how you usually spell 'burn' BoB!

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:hysterically_laughi

Nice one Kooky!
Yeah BoB I'm going to change the oil again at the weekend.

Can't sell/burn it cause nothing but another P38 can do the job mine does for the money.
Yesterday I had to drive from Tralee to Castlebar (200 miles on Irish roads), then take off up a mountain along forest and bog tracks, do some work involving walking for several miles across the mountain with geotech equip and then drive 200 miles home again. Tiring stuff, and I do this all the time. The vehicle has to be right. Company has a Freelander but it can't get to where the P38 can go.
A Defender will chew up the off road stuff but chew me up on the road. X5/Toureg will eat the road but get swallowed whole by the tracks. An LC Amazon would be up to the job as the next best thing but cost too much and a little souless. I'm undecided about whether the indie suspension and monocoque chassis of the D3's and RRS's/L322's are up to the constant off road when they do come down enough in price.

So its P38 for the foreseeable future for me.

SpudH said:

:hysterically_laughi

Nice one Kooky!
Yeah BoB I'm going to change the oil again at the weekend.

Can't sell/burn it cause nothing but another P38 can do the job mine does for the money.
Yesterday I had to drive from Tralee to Castlebar (200 miles on Irish roads), then take off up a mountain along forest and bog tracks, do some work involving walking for several miles across the mountain with geotech equip and then drive 200 miles home again. Tiring stuff, and I do this all the time. The vehicle has to be right. Company has a Freelander but it can't get to where the P38 can go.
A Defender will chew up the off road stuff but chew me up on the road. X5/Toureg will eat the road but get swallowed whole by the tracks. An LC Amazon would be up to the job as the next best thing but cost too much and a little souless. I'm undecided about whether the indie suspension and monocoque chassis of the D3's and RRS's/L322's are up to the constant off road when they do come down enough in price.

So its P38 for the foreseeable future for me.

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That's really interesting. What tyres do you use?

Naah it's just the new colour code, so that some people on here will know which is the front and back axle.

I have heard that if the breather tube is blocked it can lead to milky diff oil. Dont know why.

OXO said:

That's really interesting. What tyres do you use?

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I'm on Pirelli Scorpions all round and have always been. The only other tire I was happy with on my RRC was Cooper Discoverer ATR but they don't make it in 255/65/16 so I stuck with Pirellis on the P38. S/T's preferably but STR's on the front at the moment. I'm not overly happy with the STR's, I don't need sticky road tyres so they fall on the wrong side of soft compound/tire wear equation. I'm not getting 20,000 miles out of them before they've gone too risky on their marginal off road grip. I've always been happy with S/T's, Good grip on/off road, reasonable tyre life, good puncture resistance (important on forest tracks). But they're getting really hard to get so after a bit of reseach I've decided to replace the STR's with Toyo Open Country A/T's when the time comes as I said on the tire poll thread.
I've got some 'interesting' tramlining problems on two particular bends at the moment so I'm interested to see if it is purely tire or if my steering damper is shot.

dannys said:

I have heard that if the breather tube is blocked it can lead to milky diff oil. Dont know why.

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Interesting!!!

I presume that would be down to condensation building up producing water in the oil. Must check that out.

Wammers, that would be just too simple a concept for LR to adopt!!! Unless they linked it to the BeCM via a light sensor to confirm the milkyness was the correct hue to throw up another fault message prompting them to tell you that a replacement axle was the solution to your fault code

SpudH said:

Interesting!!!

I presume that would be down to condensation building up producing water in the oil. Must check that out.

Wammers, that would be just too simple a concept for LR to adopt!!! Unless they linked it to the BeCM via a light sensor to confirm the milkyness was the correct hue to throw up another fault message prompting them to tell you that a replacement axle was the solution to your fault code

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I like yer thinkn........ooops in the posh section.....i'm lost.......i'm off to the chavvy section bye

SpudH said:

I'm on Pirelli Scorpions all round and have always been. The only other tire I was happy with on my RRC was Cooper Discoverer ATR but they don't make it in 255/65/16 so I stuck with Pirellis on the P38. S/T's preferably but STR's on the front at the moment. I'm not overly happy with the STR's, I don't need sticky road tyres so they fall on the wrong side of soft compound/tire wear equation. I'm not getting 20,000 miles out of them before they've gone too risky on their marginal off road grip. I've always been happy with S/T's, Good grip on/off road, reasonable tyre life, good puncture resistance (important on forest tracks). But they're getting really hard to get so after a bit of reseach I've decided to replace the STR's with Toyo Open Country A/T's when the time comes as I said on the tire poll thread.
I've got some 'interesting' tramlining problems on two particular bends at the moment so I'm interested to see if it is purely tire or if my steering damper is shot.

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I had Scorpion STs on mine originally which were amazingly good but the tyre place put STRs on by mistake when I had to buy replacements. They claimed it wasn't their fault as the STRs had been given the same stock code as the now obsolete STs and they couldn't find a single ST in the whole of the UK (bit irritating as I phoned them specifically to check that they had STs beforehand).

So I tried them for a week and they were absolutely AWFUL on my P38. It tramlined dangerously and they were useless off road. not like the STs at all.

So I went back and swapped them for General Grabber AT2s instead. They're excellent - I would certainly recommend them.

Guy

Same principal as boat trailer hubs. Tow boat to sea. hubs get hot, air expands. Dip in sea, hub cools, air contracts, sucking in water. Axle gets hot, air expands, go in deep water, breather to low or not connected, axle cools, air contracts, sucks water into axle. Simples. If you don't believe this, obtain milk bottle, fill with steam, place willy in neck of bottle, wait for steam to cool. Have hammer handy to break bottle.

wammers said:

Same principal as boat trailer hubs. Tow boat to sea. hubs get hot, air expands. Dip in sea, hub cools, air contracts, sucking in water. Axle gets hot, air expands, go in deep water, breather to low or not connected, axle cools, air contracts, sucks water into axle. Simples. If you don't believe this, obtain milk bottle, fill with steam, place willy in neck of bottle, wait for steam to cool. Have hammer handy to break bottle.

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And you know this about the milk bottle how....?

wammers said:

Same principal as boat trailer hubs. Tow boat to sea. hubs get hot, air expands. Dip in sea, hub cools, air contracts, sucking in water. Axle gets hot, air expands, go in deep water, breather to low or not connected, axle cools, air contracts, sucks water into axle. Simples. If you don't believe this, obtain milk bottle, fill with steam, place willy in neck of bottle, wait for steam to cool. Have hammer handy to break bottle.

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Milk bottles, what are they?

kooky_guy said:

And you know this about the milk bottle how....?

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Not from experience i can assure you. It's just the old trick of putting an egg inside a milk bottle. Soaked egg in vinegar until shell softens, then put steam in bottle. Place egg on neck of bottle, as steam cools it sucks egg into bottle. Shell hardens one egg in one bottle. Magic. Try egg trick with your kids it will amaze them. But i would suggest not to try it with wedding tackle. Same principal that creates mayo in engines that do short journeys. Air in crankcase expands as it heats, then as it cools and contracts moisture is drawn in. The engine never gets hot enough to burn it off so the mayo is formed. Commanly know as fools head gasket failure.

The CV grease from your swivel joints is leaking past the oil seal into the axle housing and contaminating your diff oil. It's nothing to worry about as far as the diff is concerned. However, at the least, it probably means your swivel joints need topping up with CV grease. You can buy it at Halfords. Use a plastic syringe to suck it out of the tin and inject it into the swivel housing (375ml is the required amount from dry). If the oil seal is very bad you'll need to change the oil seals, but it's a big job and if you doing it you might need to change other parts at the same time.

or it could be water ingress.

WoodyJon said:

The CV grease from your swivel joints is leaking past the oil seal into the axle housing and contaminating your diff oil. It's nothing to worry about as far as the diff is concerned. However, at the least, it probably means your swivel joints need topping up with CV grease. You can buy it at Halfords. Use a plastic syringe to suck it out of the tin and inject it into the swivel housing (375ml is the required amount from dry). If the oil seal is very bad you'll need to change the oil seals, but it's a big job and if you doing it you might need to change other parts at the same time.

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This is over 3 years ago......