i got a 93 bronco 351w.i have a bad oil leak from the rear of the engine.im thinking its either the oil pan or the rear main.heres the strange part (or what i think is strange),when the nose is facing up hill so the rear of the engine is lower,it dont leak that bad at all.but when i park it with the nose going down hill the oil pours out the rear of the motor.the starter and y pipe and cat heat shield is soaked.all the oil pours out within 10 min or so.if i park it the other way,i might have a half dollar spot in about 2 days.i cant figure it out.if anyone could help me out with any thoughts that would be great.thanks

 

Are you sure it's oil? Could it be transmission fluid? I assume you check the oil and not the transmission fluid. It could be the rear main leaking into the bellhousing. I have seen some people "fix" a rear main oil seal by using RTV around the bellhousing and inspection cover. What happens then is the oil just builds up in the bell housing until it finds a place to escape. Other than that, you have me baffled.

 

that makes total sense what your saying.its definately oil cause when it all leaks out,the dipstick reads nothing.how much should it cost to change a rear main seal at a service station

 

If is leaking that much oil I would think it is the pan gasket more then the rear seal.

 

i was thinking the oil pan too.but why would it only leak when its nose down.the entire motor and pan is dry except the back of the motor

 

Cost varies on location, so I wouldn't really be able to tell you that. I'm about to do the rear main on my bronco, but I'm doing it myself. The seal was only like $10, but the work involved is a bit time consuming. It requires the transmission be out because you have to take the flex plate off to get to it, and it's a single piece seal. call around your local shops and see what it will cost. Personally, I'd drop the transmission out, and remove the flex plate and see if that's actually the problem though.

 

That's a *bit* of understatement...

The first (and last) time I did a rear main seal I spent a whole weekend on it, though with experience, right tools, an occasional helper, and a bit of luck (no broken or rusted in bolts, studs, nuts, etc.) it can probably be done in a few hours.

 

The most time consuming thing to a Bronco rear main (302 for sure, not sure about the 5.8) is removing the transmission. These are big, burley gear boxes, and I had to drop my exhaust to get it out. I did however get to use my new saws-all to remove the exhaust. :-) Anyway, after the transmission is out of the way, you just have to take the flex plate off, and remove the old seal and replace it.