Mystery, Oil leak located near Rear Main Seal but not RMS

Engines, Transmissions & Final Drive questions and answers

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hks_kansei
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Re: Mystery, Oil leak located near Rear Main Seal but not RM

Postby hks_kansei » Tue Feb 16, 2016 10:30 am

Seals can still leak despite looking normal, they dont need to visually come loose.
So it may still be the rear main.

Could you see any oily dribbles?

could be the sump gasket, rear main, etc.
1999 Mazda MX5 - 1989 Honda CT110 (for sale) - 1994 Mazda 626 wagon (GF's)

RS2000
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Re: Mystery, Oil leak located near Rear Main Seal but not RM

Postby RS2000 » Tue Feb 16, 2016 11:07 am

Has wrote:But i removed the G.B, clutch and flywheel and as i was removing the flywheel bolts oil did start coming out (I didnt know that the flyhwheel bolt holes would leak oil) Im not sure off by memory if i torqued it properly but Im pretty sure i did. But the rear main seal is perfectly intact. So i really do not know what the hell is going on. My only answers that ive fabricated is that the bolts had too much loctite and didnt allow full travel of the bolt's thread? but it still doesnt make sense, because loctite shouldnt restrict the bolt's travel. A friend, told me about using a spring washer to tension the bolts now i dont know if this would work but it seems legit. The motors ive worked with never came with a spring washer to go under the bolt heads of the flywheel to crank.

I want to do some serious digging before i put it all together again and screw it up again and really consider driving off a cliff haha.

Would anyone be able to tell me what may have caused this leak (due to the shock? dont really know). Something to do with engine oil pressure? If so can you please elaborate for me as Im still a beginner. Are my investigations correct about too much loctite?


Do NOT use spring washers on flywheel bolts. Flywheel bolt holes in crank would be blind, so wouldn't leak oil, but I guess you could fill with Loctite & bolts not do up - but you would have noticed a loose flywheel.
Leak could be between seal ID & crank, seal OD & housing, block & sump, or g/box front seal (hopefully not).

project.r.racing
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Re: Mystery, Oil leak located near Rear Main Seal but not RM

Postby project.r.racing » Tue Feb 16, 2016 1:33 pm

Flywheel bolt holes don't have the means of oil to come out of them.

If oil around/inside bellhousing, the motor is not the only place fluid could come from.

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Rolley
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Re: Mystery, Oil leak located near Rear Main Seal but not RM

Postby Rolley » Wed Feb 17, 2016 7:00 am

I was certain my rear main would be the culprit of my oil leak. It was only 2-3 drips on the try under the car over night and after washing everything down and checking the only place oil was visible was coming out of the bottom of the bell housing.

When the clutch failed I was expecting to find it oil soaked and destroyed from the leaking seal, only to find everything dry and the seal perfect when the box came out. The oil had been weeping out of the head gasket at the very back left hand corner of the head and straight into the bell housing. It was easy to spot from underneath with the box out and virtually invisible with everything back together.
I ended up swapping in a fresher/younger motor instead of doing the gasket.

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1600Dave
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Re: Mystery, Oil leak located near Rear Main Seal but not RM

Postby 1600Dave » Wed Feb 17, 2016 3:23 pm

Factory service manual says rear seal should range from flush to 0.5mm inside the housing.

I've just finished an engine swap, used a non-genuine mania rear seal and it works fine.


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