Rear main engine seal

[cisco]

Hi guys,

Do you reckon having a hot flywheel/clutch would make this seal fail prematurely? Or are they pretty tough? I haven't had mine out before, but I am about to go get it out.

I only ever get this overheater clutch issue when I have competely stuffed up a gear change etc, It NEVER happens just from smooth driving.

Cheers.

 

[CMF_evade]

eh possibly.

as for the more meaty flywheels (ie errol's alloy one) comapred to the thinner ones (jun) transferring less heat..i think this might be offset by the different materials used in their construction.

ie errols:
"These wheels have a higher thermal absorption mass than steel flywheels due to the greater volume of alloy"

while the chromoly might be more heat resistant.

 

[cisco]

Yeah its hard to tell isn't it. Good point.

I just don't want to punish myself another $700odd to slap one of those in there and find it still does the same if I stuff up a launch. I think any flywheel is going to get kinda warm with 144kw at the wheels smoking through it under full throttle when a gear is missed.

Plan of attack: Shortshifter is gone, that will help me be a bit more accurate. Drive smoother, be more careful. Just pull it apart, straighten the fingers back out, fix the seal, and drive it for a while like that.

 

[CMF_Alex_B]

Off topic, but >

Car must be getting abit like lego now hey cisco, drop the gear box off...oh yeh...whatever . I had my front brakes off yesterday, for repainting and fitting new pads. Can't believe how quick i got them off. While i was at it i remove one of the front control arms and cleaned+regreased the whiteline castor/anti-lift bush, i was like crikey alex, last time it took you half a day to get this off, had it off in 15min after struggling with a splitpin, haha,

Alex

 

[cisco]

Fully know what ya mean mate, most definately.

You definately get quicker every single time.

I reckon I've dropped a micra gearbox 4-5 times now. Today will probably be the 5th time. And in my car's, its easier. there is no ABS, there is no battery. So you basically undo the bonnet and immediately begin unbolting the gearbox. Saves a fair bit of piss-farting around. Also, because everything's already been out recently, it means nothing is usually ceized etc.

Only problem with my gearbox refiller plug is locked on, I warped a 3/8" drive ratchet on it literally 45degrees belting it with a hammer to try and budget the filler plug.

Oh well, I just know to use the speedo drive hole to fill it up, and that's pretty easy to get to and has a nice big obvious nut to grab hold off with my 22mm spanner.

 

[cisco]

BEGIN gearbox removal.

I'm timing myself this time.

 

[CMF_White Knight]

Ciscos Micra repair shop.
All work done quickly and efficently.
Specialise in clutch/gearbox removal and repair.
Modifications a speciality.

 

[CMF_White Knight]

Cisco. You started 1.30 pm. Now nearly 4pm. All done??

 

[CMF_Yom]

The other thing which can cause premature seal failure is a poorly machined crank. Even a poorley machined (heck even a slight scratch or the slightest divot in the metal) seating area around the outer side of where the seal goes.

There's also possibility of a dodgey seal or someone installed the seal incorrectly. If you bend it too much the more you can a) put it out of shape and b) weaken its structure.

Just reading the amount of KM your motor has done since the rebuild - I don't see how just the heat from the clutch is enough to cause problems. If it is leaking already there's gotta be something else which caused its failure.

Heck they're meant to last at least 100,000km.

 

[cisco]

Bah, had to call dad for his birthday, had to go in the relia-mont and pick up the girlfriend.

Its been very disruptive! About to go back into it. Literally almost done. I've spent 1hr 30 mins on it so far.

Everything is undone, including bell housing bolts, wheels and shafts are off, fluid is drained, starter motor is out. Jack is now supporting gearbox about to remove the 2 final engine mounts (at the front) and pop the box off.

I would safely say within under 2hours the gearbox can be completely off and removed including clutch and flywheel removed. I reckon 20 minutes and I'll be finished removing everything.

 

[CMF_evade]

Did they change the real seal when they put the jap engine in?

 

[cisco]

I'm pretty sure I remember Jake specifically changing it.
But could be wrong.

Weird.

Everything is off the car. I found a couple of things, but no HUGE evidence like I would have perhaps expected.

There was some splatters of engine oil around the rear seal. It was definately engine oil and not grease or anything else. But it was only like 6 drops. But I guess that's enough to be considered a slow leak??? Especially when things are spinning fast enough pulling 8000rpm that should be plenty enough to fling a few drops of oil out right?? So that's that.

Now I have no hope of removing this rear main seal without some kind of tool or whatever. YOM/Anyone, what tool do I need? Is it a "sneeky pete" or something like that? How much does it cost?

Seal looks pretty nice and intact, apart from those oil drops. But I guess you aren't going to see huge bad damage for a slow leak right?

Now pressure plate, that's another story. I was expecting to find like half the fingers really badly bent out of shape.

Now seriously, they almost looked perfect. I found about 4 of the fingers were ever so slightly out of alignment, so I bent them back into alignement. Not sure if they were out enough to cause the badly vibrating clutch pedal that I had though. So this really weird. The pedal had a very distinct annoying vibration pattern to it. And it specifically happened after a bad launch. Now damn I hope the entire flywheel isn't warped or something. That is quite a possibility, so I will prob take it all to a machine shop and get someone to check that everything is well balanced (clutch and flywheel).

Bloody weird. Well anyway, I hope all this effort of pulling the car half apart was worth something. Some oil drops are a pretty good sign aren't they, but nothing hugely warped looking. But a lot of slight warped things you can never ever tell by eye. Will get it checked out.

Ahh well we're getting there. Glad the coolant leak is fixed anyway.

 

[CMF_jamm'n]

sorry tom. just trying to push things on for Aaron a bit so i'm quoting your thread on Chris's clutch install.

"THe Haynes manual doesnt tell you how to remove the seal properly. Well... IT does but you don't have to do what it says unless the factory gasket goo around the plate has failed and is leaking oil.

All you need to remove the rear main seal is a oil seal puller (this is the safest way so you don't damage the seal seating - ruin that and you're screwed). Chris pulled it out with some extra expertise and creative thinking.."

this is the thread.https://micra.org.uk/cmf/message/14250

 

[cisco]

Ah ha ch33rs matty. Will go read that.

 

[cisco]

Hmm bah. Doing some reading on rear main engine seals.

And this .. "The seal can also leak due to old age, or from an extended vehicle storage period that allows the seal to dry out and crack."

Extended vehicle storage periods!!!

Also possibly if the crankshaft is out of balanced and causes it to upset the seal. Damn I hope that's not it. Pfft can't be, this engine is so damn new.

 

[cisco]

And this.. "Oil can drip down the back of the motor and out of the bell housing and create the exact same symptom as a rear main seal (RMS) leak. It is always best to check your valve cover as closely as possible for leaks and fix them before doing the RMS."

Damn don't be this!

 

[cisco]

There is also some talk about it being important to replace both flywheel and pressure plate bolts after each removal. Depends on the make and model I think. Some are saying replace them after every removal, others say after several removals.

Has anyone heard about this for the micra? Any tips??

 

[CMF_Yom]

Mate if it was a rocker cover seal of the dizzy seal you'd see it trickling down quite clearly.

Have you cleaned the flywheel yet? Trademark signs can be the dust and grot on the back of the flywheel looking like they're making little trails away from the centre of the flywheel. Formed from tiny amounts of oil being flicked away.

I reckon its time for you to whip out the haynes manual and re-do that plate part they talk about.

You have to admit that your engine builder was quite lazy and a few small things like seals may not have been done properly.

As for removing the seal. Very easy! Find some tiny little screws and screw them into the seal in various strategic locations (don't screw them in too far).

You should be able to get some pliers and pull the old seal out without damaging anything.

Alternatively yes you can buy a seal puller etc

Goodluck with it

 

[CMF_Yom]

none of the micra's clutch or flywheel bolts need to be replaced. They don't stretch into position like some headstuds/bolts.

 

[cisco]

Ahh cheers. Glad I don't need new bolts. That would be yet another stuff around to go and chase up from Nissan-no-parts-Australia.

Check this out. Here's a pic of the back of the flywheel. You can see the engine oil in the middle that was pressed against the end of the crank, and also this is a trail of oil going outwards like you mention. However, note its the only one there. Perhaps I picked this leak up early ??

Those splots of oil in the middle were on the end of the crank aswell. But I wiped that clean, so I don't have a pic of that.

 

[cisco]

Here's a pic of the rear main seal itself.

Note: Stupidly, this is after I wiped it clean a fair bit. But it wasn't terribly dirty. There was oil drops on the big alloy circle thing matching those obviously on the inner plate of the flywheel as per the last pic where they were touching/pressed together.

There is a bit of oil/gunk looking crap still around the edge of the seal in certain areas as you can see. Does it look leaky ? That bit on the left hand side kind of looking a bit dodgy. Well I'm certain oil is getting out somehow, hence the oil droplets on flywheel.

 

[cisco]

I also had a quick crack with the tiny screws trick.

First: I did it in the wrong spot, the screw went through and it touched metal. So I quickly backed off not wanting to damage any of the metal.

Next: I put it in another spot and then its too close to the inner edge of the metal thing.

So I have jabbed 3 tear holes in this seal now, and I wimped out again not wanting to risk ruining any of the metal on this very $$$ engine.

I'll just get a puller tomorrow.

 

[cisco]

Oh and you'll never guess what..

Now that I have half of this **** out of the way.. Guess what I found.. Another apparent oil leak from up behind the head and dripping down!!!

I needed to remove the gearbox anyway to fix the vibrating clutch and I found oil in there, so HAD TO HAPPEN anyway. But looks like old Blue Monster has yet another leak. Oh ****, what a piece of ****! I'm not sure why I pay these idiots to rebuild me a fresh engine.

Check out this photo:

 

[cisco]

After further inspection, that upper oil leak actually appears to be oil squirting out of the intake manifold and dripping down onto the head. Its only coming out of runner #1. Well the passenger-side most runner.

Now I know turbo's suck in a bit of oil from the filters etc. But right now, my turbo is leaking oil quite considerably. That's why the car is booked into Intune next week.

I wonder if its possible that the inners of the turbo are a bit leaky and oil is getting into it somehow. Doubt it, but who knows, perhaps possible.

This car is a bomb.

Oh well, one problem at a time. I will order the new rear main seal tomorrow and go buy the puller tool. I'll also drop the flywheel and clutch off to a drivetrain place to make sure nothing is warped.

Once the car is all back together with all that done. I can then further investigate the upper oil leak.

 

[CMF_Yom]

Either the guys who build your engine were very sloppy with greasy hands when putting it back together or you caught that seal nice and early.

That top oil leak is no good. No good at all. If I were you I'd drain the sump and do what the haynes manual explains. I can see the factory bolts have been undone before so you may as well pull it off and make sure its done properly. Time to start taking precautions in regards to seals, etc.

 

[CMF_Yom]

Oh yeh, take a closer look at that welsh plug just above the crank. I don't know if what i see there is red gasket goo or some form of corrosion.

Oh and May I suggest a drive-by brick throwing at a particular business. lol

 

[cisco]

Yeah I'll go check that plug right now. Cheers. So many things!

Honestly, I can't continue to put up with these kind of problems day in day out. The value isn't there for me. This was why I cracked and almost sold the car. Once you modify everything, its problem after problem just getting it running.

It annoys me too much.

 

[CMF_jamm'n]

god, i'm scared to look under my car now.
sheeeeesh.

 

[cisco]

I reckon, its kinda scary huh matty.

I'll order another seal from Nissan today. Meanwhile also get the clutch and flywheel checked for balance.

Not a lot remaining really, once I get the seal, bolt the car all back together, probably Monday. Then it goes to get the turbo's oil leak fixed on Wednesday. Before long there will be zero leaks of any kind.

Great effort = Great achievements!! Just got to remember that. MMMmmm great effort. Mmm effort.

 

[cisco]

I am absolutely committed this time in making the June long weekend meet with my car fully 100% sorted and running SMOOTHLY. Can't wait.

 

[cisco]

New rear main seal just ordered from Nissan.

Cost: $86. Will be here 10am Monday. At least they can kind of get stuff overnight.

I'll grab some new gearbox oil, new split pins for the hub nuts, and a seal puller. And we'll be on target for having the car back in one piece by Monday arvo.

Cars huh. The good thing is, that I reckon I've saved approx $500 labour by doing all this myself.

 

[cisco]

Just had a yarn to Family Hack on the phone.

After some more thought and another inspection of that upper leak.

I am now thinking its not an oil leak, and its a small fuel leak. Coming out of runner #1.

There are absolutely no signs of oil in any of my intake pipes anywhere. They are all dry-as - which is a good thing.

There is no way that much oil could be coming out of #1 runner whatsoever.

I really think now its a bit of fuel leaking out of the inlet manifold gasket, and by the looks of it, mixing with dirt and grime, and hence it appears a bit more milky etc.

So pretty sure I just need a new inlet manifold gasket, or perhaps it could even be the injector not seated in its O-ring not quite correctly and gasket might even be fine. Either way, its neither here nor there. And I need to get some small injectors anyway so that the car doesn't have such a rich idle. So this might be the perfect excuse just to get all that done in one bang.

Anyway, I have wiped all the fuel/grime/oil/whatever away from it, everything is clean, so I will keep an eye on it now and see where any future drips come out from. My guess is that it won't drip any more while the car is just sitting there because the engine isn't running, so if its a fuel leak, nothing will come out until I turn the engine on again.

Yay at least I will have a balanced clutch without vibrating pedal, and a new rear main seal. Glad about that.

 

[CMF_Yom]

Yeh well lets hope that the place skimming your flywheel and clutch won't fudge it up.

Might be an idea to find out how many times you can machine the JUN flywheel too - no doubt it can only be machined a certain number of times before it breeches structural integrity.

Don't forget to re-lube up the input shaft and throwout bearing by rubbing some graphite powder onto it!
Oh and put that black sandwich plate on the motor before you put the flywheel back on.

Good luck as usual!

 

[cisco]

If the JUN is not warped, I won't be getting it machined.

They say even in the Nissan workshop manual to only go over it lightly with emery paper. That's all I did last time, and the clutch has bitten perfectly, never slips etc.

Yeah will have to re-grease that stuff very lightly, cheers.

I was also thinking, chances are its the pressure plate that's warped if anything. The flywheel is a tank made of full on solid high grade chromoly, the pressure plate is pretty cheap and skimpy by comparison. I'd be most suspicious about it.

 

[CMF_Alex_B]

think your spoton there cisco, check taht pressure plate, its far more likely to give out. when i did my clutch it was lightly scored whereas the flywheel was nice,

Alex

 

[CMF_White Knight]

Agree. Will be the pressure plate not the flywheel.

 

[cisco]

Cheers.

 

[cisco]

Part arrived. Here 'tis:

 

[cisco]

Just rang up a really good transmission shop.

Described that the pedal was just vibrating etc, but it engaged perfectly and never shuddered never slipped etc.

He said would just be some tiny differences in the fingers on the pressure plate - as suspected. And that the flywheel/pressure-plate shouldn't be warped.

So I'm simply going to double check again that the fingers are all dead even, and then re-install everything after going over the flywheel with some emery paper.

Just psyching up to go and change the rear main seal shortly and get her back in one piece again. Aiming to have the car driving once again tonight.

 

[cisco]

How am I going to remove this rear seal??!

Its pretty hard to screw tiny screws into it because it has metal inside it. So you would need to drill them through, then I don't want any metal schrapnel or filings finding their way into the engine oil - no way dude.

Impossible to lever it out without scratching the metal around it.

Hmmmmm...!!!

 

[cisco]

Hey Yom,

you said "All you need to remove the rear main seal is a oil seal puller (this is the safest way so you don't damage the seal seating - ruin that and you're screwed). Chris pulled it out with some extra expertise and creative thinking.."

Can you elaborate on this creative thinking mate?

Thanks

 

[CMF_GTRHOLIC]

cisco, thats exactly what i did. i screwed quite a big screw into it cos it is soft around the metal ring. i removed the screw and then used a snap on pick and awl (is that right?) kit to pull it out.
hope this helps

 

[CMF_Yom]

I've directed chris to this thread. he should be to your rescue in a moment.

There's a small possibility that your australianised mechanic may have used some gasket goo to seat this seal (alot of australian cars require this, N13 pulsars with the GM family II motor do anyway).

If he has used gasket goo you'll have to drain the sump and follow the haynes manual to remove that whole seal seating area and clean it all out and hope there's no damage to the aluminium.

 

[cisco]

Thanks..

There doesn't appear to be any gasket goo around it.

The gasket goo silicon stuff around the aluminium housing thing also doesn't appear to have any leaks coming from it whatsoever, it seems perfectly intact and the silicon stuff is still very fresh and soft. So I would prefer to leave that in place.

The only thing that I can think of right now is to lightly drill small holes through the seal, then wind in screws into those holes so the screws bite. Then leverage it out with some pliers etc. Hmm.

 

[cisco]

Hmmm ok cheers mate.

I have hacked some of the soft rubber away from the inner edge, i.e. where the metal crankshaft ring is..

I could look for something with like a pick/catching thin edge on it to shove down there and lever it out with perhaps..

 

[cisco]

Hey GTRHOLIC, did you just lever it out in one spot?

Or did you put screws around in a few spots and then lever out in a few spots etc? Or juts one was enough??

 

[cisco]

This suXors.

You should see this metal custom thing I just made up and BENT the crap out of trying to get the seal out.

Thought I almost had it, but instead of the seal budging, the metal thing bent back and slid back out. Allright, thinking about getting the drill out.

 

[cisco]

yay got the sucker out.

 

[cisco]

Allright a couple of pics.

What I did was use about a 1-2mm drill bit and pre-drill 3 small holes in the centre stiff part of the seal (the part that has a metal backing). You need to be gentle, but after a bit of light drilling, you will feel the drill pop through the metal. That is a good time to stop drilling.

Then I put these 3-4mm self-tapping screws into the holes just with a screwdriver, just wound them in a few turns, and they felt very well secured into the seal's metal.

Then I just worked it out with pliers levering off the edge of the sump.

This works and doesn't scratch anything at all. Just be gentle with the drill etc and you can't hit anything.

 

[cisco]

.