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Front Diff - Oil Leak
- Thread starter chadr
- Start date
Have you checked for the easy stuff like loose drain / fill plugs or drive shaft oil seal? Needs a good clean and then watch to see where oil first appears again. Might even be off something else and landing on your diff ...
The Oil seal on the passenger side of the diff failed on mine, lost all the oil (1.1litres)
Going up a moderate incline on a motorway, the pinion carrier bearings failed and resulted in the diff locking up.
The bearings are only splash fed and any lowering of the oil level can result in them running dry with bad results.
Going up a moderate incline on a motorway, the pinion carrier bearings failed and resulted in the diff locking up.
The bearings are only splash fed and any lowering of the oil level can result in them running dry with bad results.
chadr
Well-Known Member
I've degreased and cleaned the whole area last night, so hopefully will be able to see where the leak originates. I haven't had a chance to take a decent look - waiting for it stop raining.
We're planning to go see my BiL up the Scottish Highlands over the half-term week, which will be a nearly 1500 mile round-trip, so you've got me worried now....
We're planning to go see my BiL up the Scottish Highlands over the half-term week, which will be a nearly 1500 mile round-trip, so you've got me worried now....
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chadr
Well-Known Member
The engine oil level is spot on - I check that regularly and I've never had the need to top up in between services yet.
So I'm fairly confident that it isn't engine oil on there..........unless it's from the last oil service, when I made a bit of a mess of the oil filter removal. However there is a small "tray" under the oil filter housing to catch any leaks, with a pipe that directs the spill towards the sump, so probably not engine oil.
I'll check the diff oil levels - the diff oil was changed just under 2 years and 15k miles ago.
So I'm fairly confident that it isn't engine oil on there..........unless it's from the last oil service, when I made a bit of a mess of the oil filter removal. However there is a small "tray" under the oil filter housing to catch any leaks, with a pipe that directs the spill towards the sump, so probably not engine oil.
I'll check the diff oil levels - the diff oil was changed just under 2 years and 15k miles ago.
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chadr
Well-Known Member
Well checked the diff oil level and it certainly seems low - hooked my finger in up to the first knuckle and barely got any oil on the tip of my finger. What is in there is VERY black.
So I popped down to the local MF and picked up some 80w-90 and will change the diff oil completely and see how things go......
Looking at the cleaned diff, it looks like the leak is coming from the rear of it, though I can't locate the exact location just yet.
Thanks again for all your help.
So I popped down to the local MF and picked up some 80w-90 and will change the diff oil completely and see how things go......
Looking at the cleaned diff, it looks like the leak is coming from the rear of it, though I can't locate the exact location just yet.
Thanks again for all your help.
good job you checked the oil level by the sounds of it.
I recommend checking the level frequently, after my experience I realise that the amount of Oil in the front diff is marginal, given that the back diff does the same work because its permanent 4wd then an oil capacity roughly 1/3 of the rear diff is really asking the oil to work hard.
The position under the engine next to the hot oil sump and limited airflow is another thing that is sub-optimal .
I notice the 120 series has a vent in the plastic undertray directing air to the diff, signs that Toyota recognise the issues with the 90 series front diff.
Plus its a pain to get to and check.
The position under the engine next to the hot oil sump and limited airflow is another thing that is sub-optimal .
I notice the 120 series has a vent in the plastic undertray directing air to the diff, signs that Toyota recognise the issues with the 90 series front diff.
Plus its a pain to get to and check.
chadr
Well-Known Member
Well after a bit of a struggle trying to undo the drain plug - spent half the day with that; ended up needing a heavy duty hex socket set and 30inch breaker bar! It seems that a previous attempt was made by a cold chisel and hammer and the gouge had gone through the mating surface of the plug and even dented the copper washer. When I finally did manage to remove it, there was no swarf as such on the plug magnet, just a bit of sludge.
I seem to have somehow managed to take the picture so you can't see the damage to the plug/washer in the pic - even now I'm not quite sure how I managed that!
The level wasn't as low as I had initially thought - there was nearly 1 litre in there, out of a total capacity of 1.1 litres. The oil wasn't that bad either - it was Millers fully synth stuff and again, hadn't deteriorated as much as I initially led you to believe. The pic doesn't show it but the oil was still quite translucent and greenish-yellow.
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I have a suspicion that the leak maybe at least in part, caused by the drain plug not seating 100% due to the damage to the mating surface and washer. However would that explain how the oil covers pretty much the whole of the bottom of the diff?
Anyway, I will order a new drain plug and washer on Monday and fit it with some new oil and keep a close eye on it. I checked the top of the breather tube from the engine bay and that seems OK. What is the best way to access/check in at the diff end?
Looking further back under the truck, I then noticed this......
I feel a whole new thread coming on.......
Thanks again for you help and support.
I seem to have somehow managed to take the picture so you can't see the damage to the plug/washer in the pic - even now I'm not quite sure how I managed that!
The level wasn't as low as I had initially thought - there was nearly 1 litre in there, out of a total capacity of 1.1 litres. The oil wasn't that bad either - it was Millers fully synth stuff and again, hadn't deteriorated as much as I initially led you to believe. The pic doesn't show it but the oil was still quite translucent and greenish-yellow.
I have a suspicion that the leak maybe at least in part, caused by the drain plug not seating 100% due to the damage to the mating surface and washer. However would that explain how the oil covers pretty much the whole of the bottom of the diff?
Anyway, I will order a new drain plug and washer on Monday and fit it with some new oil and keep a close eye on it. I checked the top of the breather tube from the engine bay and that seems OK. What is the best way to access/check in at the diff end?
Looking further back under the truck, I then noticed this......
I feel a whole new thread coming on.......
Thanks again for you help and support.
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Oil is notorious for spreading out and getting places you wouldn't always expect so it's possible. Best bet is to put a new washer on like you plan, clean it up, fill it up and see how it goes.I have a suspicion that the leak maybe at least in part, caused by the drain plug not seating 100% due to the damage to the mating surface and washer. However would that explain how the oil covers pretty much the whole of the bottom of the diff?
chadr
Well-Known Member
I fitted the new drain plug and refilled the diff, week before last.
Just come back yesterday from a week's (1.3k mile) trip to the Scottish Highlands and just rolled over 150k in total, the front diff is still bone dry, so the suspect diff drain plug is the most probable cause.
Will still need to investigate the transfer case leak - which looks like a flange seal?
Just come back yesterday from a week's (1.3k mile) trip to the Scottish Highlands and just rolled over 150k in total, the front diff is still bone dry, so the suspect diff drain plug is the most probable cause.
Will still need to investigate the transfer case leak - which looks like a flange seal?
