Is my rear main the culprit?

[speedracerturbo]

Ok first the back story: I just completely rebuild my s13 sr20det on a stand from bottom to top which included new main seals. Once I put it all in the car and cranked it. Up, I noticed I had a lot of oil coming out of the small hole at the bottom of the tranny (where the oil Pan and trans meet). I saw oil dripping down the back to studs that snug up the back of the oil pan so I dropped the Pan and revealed it. It only dripped a small amount of oil sitting still but when I cranked it up, it was pouring oil out again in the same way.

I removed the trans and am looking at the rear of the engine trying to see evidence of where its coming from. Can someone help me verify if its my rear main before I rip apart more of my engine? I just want confirmation or a way to know for sure.


http://i360.photobucket.com/albums/oo49/bust42/null-52.jpg (http://s360.photobucket.com/user/bust42/media/null-52.jpg.html)

http://i360.photobucket.com/albums/oo49/bust42/null-51.jpg (http://s360.photobucket.com/user/bust42/media/null-51.jpg.html)

http://i360.photobucket.com/albums/oo49/bust42/null-55.jpg (http://s360.photobucket.com/user/bust42/media/null-55.jpg.html)

http://i360.photobucket.com/albums/oo49/bust42/null-54.jpg (http://s360.photobucket.com/user/bust42/media/null-54.jpg.html)

Here I noticed some accumulated oil and I'm thinking I might also have a leak at my valve cover gasket but I don't believe it would be leaking down the head and into the bell housing and then back out.....
http://i360.photobucket.com/albums/oo49/bust42/null-53.jpg (http://s360.photobucket.com/user/bust42/media/null-53.jpg.html)

[sleepyS14se]

hard to tell but it looks ok.

[speedracerturbo]

That's what I thought also. Is there any way to test this that I don't know of? I really can't figure out where it's definitely coming from.

[Mikester]

The leak is in your tranny dude; not the rear main.

Aft of the input shaft behind the fork & t.o. bearing, you will see a plate with 5-6 bolts attached. Run your fingers around the outskirts of that panel and I bet the part that would normally be on the bottom will be wet; and there will maybe be evidence of a trail from there down to where the oil was coming out of the bellhousing. There is a gasket on that panel that breaks down over time- It may be time to open that panel up, smooth/clean the mating surface & high-temp RTV it shut.

While you have it off, this is a GREAT and SMART time to replace the tranny front/rear seals (front seal could also be the culprit here)... F & R tranny seals are the same exact part # as KA and only like $10 or less for both. Installation time for both with the tranny out of the car already is about 15min if you really, REALLY take your time. Do everything stated above and I am pretty sure all will be well for ya.

[speedracerturbo]

OMG man your a freaking genious! I think your right! I knew the oil was a lot darker and seemed thick! This makes a lot of sense. And yes there is fluid inside the bell housing and leaking down now that I pay more attention to it. THANK YOU! I hoped I wasn't a bad enough mechanic to screw up main seals!

This is the first time I've ever had a trans seal to out... So does cranking the engine cause the oil to push out at the front like that? Does it build pressure in the trans or something? I do engines, not transmissions.... Yet

[Mikester]

I am not exactly certain how gear oil 'flows' thru the tranny... but it does... I think by the motion of the gears causing a swirl effect (but totally not sure lol)... Either way, everything turning will cause the moving oil to seep out from that panel gasket or the front/rear tranny seals. Just like any other liquid, solid or gas; tranny fluid will follow the path of least resistance (leak) given the opportunity. The tranny has a breather tube, so I don't think it builds any pressure per se... however, oil expands and contracts as it heats & cools and the breather sort of maintains the status quo of air volume for lack of a better way to explain...

Another thing that may help is to use different color gear & motor oils... I use Royal Purple 75W90 in my tranny and a different color oil in my engine... If your bell housing is kept clean & maybe painted a nice color like silver; you can often tell which one is leaking by looking at the color of the drips forming at the base of the bellhousing flange.

[speedracerturbo]

^^ smart idea. I had royal purple in the trans but when it came out it just looked dirty and black. And the oil has zero miles on it. Every time I crank the car, within a minute it starts dripping out steady. And I assume its picking up a lot of trash making it dirty looking

[Mikester]

It's picking up clutch dust from inside the bellhousing (sorta like brake dust).

[speedracerturbo]

Hey guys. I've found that my trans seals are my problem and need changing. I'm trying to figure out which I'm supposed to pull from this picture and how do I get these out exactly? And I'm assuming the peep hole (above the bottom seal and to the right) is supposed to be wide open? Also I can't figure out definitively where the metal ring in the bottom of the second picture came from. It just fell out of the plate when I pulled it off. Help please?

http://i360.photobucket.com/albums/oo49/bust42/null-59.jpg

http://i360.photobucket.com/albums/oo49/bust42/null-58.jpg

[Mikester]

Yes, the hole is supposed to be open. The front seal is the rubber ring around the spline at the back of the panel (second pic)... Pry it out, pop new seal in... Use grease to lube it- done.

As far as the metal ring goes, you're going to have to figure out where it sat, and evaluate whether or not it was supposed to be fixed to any of the bearings... or maybe someone else here can tell you more (I'm not a tranny expert dude).

[S14DB]

The ring is a thrust ring for the bearing. Goes on the end.

Front seal as described above is in that cover. Remove and replace.

Put some RTV on the edge of the cover when you replace to stop weeping.