Oil Leak - Rear of Engine - Suggestions

Ol' Harley

Well-Known Member
Morning all;

At the outset...talking about a manual 2012 twin-cab Diesel GLX Triton here. And It's got over 350,000 on the clock.

For the first time since I've owned the beast, I noticed a couple of drops of oil on the garage floor the other day, underneath the engine. Never a good sign.

First thing - checked the oil level. Just a hair's breadth below full. So far, so good.

Out came the ramps, up went the ute, and ignoring the creaking and cracking of the joints (mine...) under it I got. There was oil staining all along the transmission case, but none in front of it. I wiped the excess off as best I could, and after much twisting, turning, cursing and trying to get as much light in there as I could, I think I've located the issue. From what I can see, the main oil seal at the rear of the engine has developed a slight leak. It's not gushing out, and from what I can see it seems to be mostly leaking only when the oil is hot and thinner, after the engine has been running for a while. And it's not a massive leak - as I said, the level of oil is still reasonably good. But it's going to have to be replaced before it lets go completely.

I think I already know the answer to this, but to put a new seal in , the transmission is probably going to have to come out first to be able to get to the rear oil seal, isn't it? Thoughts and suggestions are welcome.

Cheers!
 

Swaggie

Moderator
Sorry to hear that…
Mine was done recently…. Removal of gearbox, used a genuine Toyota part for this not a non genuine…

B522AFA9-15F9-4274-B121-B001F4932ADA.jpeg
 

FranksnBeans

Active Member
My rear main seal was leaking last year too. I was having the clutch replaced anyway so saved a lot on the labour. It's a lot of work to replace a $5 seal. But it's probably one of those things you shouldn't ignore for too long.

If your clutch is a bit knackered then now is the time to replace that too.
 

typhoeus

Well-Known Member
Also check the sump bolts, give them a little nip up. Sometimes the back of the sump can leak too
 

Colly18

Well-Known Member
After 350K km I'd not be surprised by a main seal oil leak. And If your clutch has been replaced relatively recently/is in good nick, then also look to replace the rear main seal before leaking oil contaminates the clutch plate. I replaced the rear main seal on a Ssangyong 4X4 dual cab ute 6 years ago and by the time the leak showed itself at the bottom of the bell-housing it had already contaminated the clutch plate. The job ended up being a rear main seal, clutch and dual-mass flywheel replacement. Not too hard a job as long as you do your research, take your time and are methodical about it. In my case it was remove the transfer case then remove the gearbox to access the clutch and rear main seal. All without a car hoist, but getting the vehicle off the ground with blocks and careful use of trolley jacks made it relatively easy (well, manageable).
 

Petunia

Well-Known Member
But. . . That won't fix an oil leak!
see, ya burn it, claim insurance, probably like a grand? maybe two? put a down payment on a oooooh lets say toyota? without a oil leak?

sought of fixed, bugger the bank account balance, is only money, no one died because of a lack of money, starvation was the cause, not a lack of money to pay for the grocery bill.
 

Ol' Harley

Well-Known Member
Many thanks for all the replies and good thoughts folks.

@Albynsw I had a similar issue and tried something like that some years ago with a different vehicle (one of the early, normally aspirated Diesel Toyota 4Runners) and it worked for a couple of months before it let go again. Not a bad thought, and if I can't get it sorted soon, it might be worth a shot until I can get it fixed.

@Swaggie I can feel your pain. I think I'm headed down the same path!

@CTL I had a thought along those lines. I have diff breathers fitted (got that done a few years ago) and had those inspected when that was done. I don't think that's the issue.

@FranksnBeans Yep, a lot of #### to get a seal replaced. So far though, the clutch is holding up well.

@typhoeus Good thought. I'll check that.

@Colly18 That sounds like a mongrel of a job. I know I shouldn't be surprised at the leak given the K's - it's been around a bit - and contaminating the clutch was something that hadn't occured to me. :oops: Note to self on that one...

@Petunia Not quite the sort of suggestion I was after. Don't think Frankenwife would be up for that one.

Thanks again folks!
 

TYNO87

Active Member
First things first, go to super cheap and buy a heap of $2 degreaser. Go to town with it, top of engine, bottom of engine, gearbox, transfer, etc (don’t squirt it in your unis), leave it sit for 20 minutes, good opportunity to flush your chassis while you wait, then gurney where you can (not electrical connections etc) and hose where you can’t. Give it a couple of days then get under and see exactly where it’s coming from. Could be some spilled oil from oil changes has finally made its way down there, could be sump bolts/ gasket, could be the rear main leaking out the front of the bell housing. Best case it disappears and never comes back again, worst case you’re where you are now, might save you pulling the box for nothing. Another thought, at 350,000kms a good degrease every 5000km oil change might get you past 400,000kms and something else might break, you might but a new car, who knows. Weigh up the cost of the repair vs the value of the vehicle.
 

Ol' Harley

Well-Known Member
First things first, go to super cheap and buy a heap of $2 degreaser. Go to town with it, top of engine, bottom of engine, gearbox, transfer, etc (don’t squirt it in your unis), leave it sit for 20 minutes, good opportunity to flush your chassis while you wait, then gurney where you can (not electrical connections etc) and hose where you can’t. Give it a couple of days then get under and see exactly where it’s coming from. Could be some spilled oil from oil changes has finally made its way down there, could be sump bolts/ gasket, could be the rear main leaking out the front of the bell housing. Best case it disappears and never comes back again, worst case you’re where you are now, might save you pulling the box for nothing. Another thought, at 350,000kms a good degrease every 5000km oil change might get you past 400,000kms and something else might break, you might but a new car, who knows. Weigh up the cost of the repair vs the value of the vehicle.

Yeah, I did a bit of that - about half a can worth - when I was trying to pin down where the leak was coming from. I'm pretty sure it's the rear main on the engine, but - at the moment - it's not massive. Some good thoughts there. Cheers!
 

Lost1?

Well-Known Member
At 350,000km on a 4d56 engine is it time to move it on? You have got a good run out of it. Rear main and new clutch is probably around $2k all up. Maybe try the nulon solution to give you another 6 months for covid car prices to drop a bit more then find something else.
 

Ol' Harley

Well-Known Member
At 350,000km on a 4d56 engine is it time to move it on? You have got a good run out of it. Rear main and new clutch is probably around $2k all up. Maybe try the nulon solution to give you another 6 months for covid car prices to drop a bit more then find something else.

You've put your finger on what's been at the back of my mind. I don't think the clutch has issues, but it's been one of those 4WD's that hasn't missed a beat for most of it's life. It's only in the past year or so as it's getting older that a few maintenance issues have started to surface - much like myself, really.

I'd like to keep it going until the after Covid / supply chain issues that are around at the moment have died down a bit, and I'd like to get one more trip out of it (possibly to the East MacDonnell Ranges) so I want to be sure I can get there and back. But I have had a pretty good run up to now.
 

Lost1?

Well-Known Member
If you want to do the east mac I would pull the gearbox and do the rear main seal and the clutch if it hasn't been done. You must be easy on the clutch if you have squeezed 350,000k out of it. But it would be so close to being shagged I wouldn't risk it.

I think it will take another two years before supply chains recover. I also think dealers and car manufacturers have rediscovered days off old, before dirt cheap drive away deals existed and will reduce production slightly so as not to flood the market and keep car prices up somewhat.

Personally I would doctor it up then trade it in.
 

Ol' Harley

Well-Known Member
If you want to do the east mac I would pull the gearbox and do the rear main seal and the clutch if it hasn't been done. You must be easy on the clutch if you have squeezed 350,000k out of it. But it would be so close to being shagged I wouldn't risk it.

I think it will take another two years before supply chains recover. I also think dealers and car manufacturers have rediscovered days off old, before dirt cheap drive away deals existed and will reduce production slightly so as not to flood the market and keep car prices up somewhat.

Personally I would doctor it up then trade it in.

There is much in what you say. I may have to think about this one a bit more, and have a bit more of a look at the market.

Much appreciated!
 
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