I have an ever so slight leak on my rear main seal. Drips a drop and it gets on the flywheel and makes my clutch chatter. Some have suggested that parking front down on a slope will help when parked. I have been wondering if that same effect would happen by running a quart low or so when parked level? The capacity is 10 qts. How many quarts would fill to the bottom of the seal when parked?

How low do I dare go without worrying about engine damage?

Thanks BB2

 

the oil level in the Pan when full is no where close to the rear seal ... so don't lower the oil level, it will not help.

 

Thanks, just what I wanted to know.

 

If you have access to a transmission jack it's not really that hard to do, because you just have to slide the trans back enough for some room just like a clutch job.

You could also check on the clutch while you're in there. Any autoparts store should be able to get you an alignment tool for around $10 so when you assemble the clutch you won't have too much trouble getting the trans to stab.

If you're 4 speed, I separate the trans from the bellhousing first, then do the forward bellhousing by itself and assemble it in reverse order, makes stabbing the trans a whole lot easier.

There's a plate that unbolts and you can do a seal in a press or on the work bench.

I have a 150$ish harbor freight trans jack, it works pretty well and beats the hell out of all the years of just using a floor jack, talk about some sketchy stuff...

I welded a single chain link to each side of the plate on mine so I can use a strap for the trans, works perfect. My only complaint is the ***** and small and hard to turn without using your hand to take some force off the jack, I think I'll cut the ***** off and weld on some T handles.

 

yeah really.. if the oil level was that high the Crank Shaft would be slapping oil all over the place


I guess after you shut it down oil that drains back down past the rear seal can still leak a bit but in that case I would say it was bad enough to need to replace the seal.
Yeah, I know PIA and I've never had any luck with Snake Oil in the can seal fixes either.

 

I was told that there were scoops on the crank that threw oil around on the bottom end. So I was thinking when parked the oil level might approach the seal. When I pulled the dip stick and tried to judge how far the static level it just seemed close to under the seal. But thanks for the information. Might try to do it some day.

I did the blue devil rear sealer and it definitely helped for a while very well but still get an intermittent leak. I was thinking of trying another application.

 

Good Gawd, that was like something on ancient model A's that didn't have oil pumps.

 

You can replace the seal without removing the plate. I did that on my '88. The seal I got came with a plastic tool to press the seal in place, I think it was a Ford part? I still have it somewhere, may been with one of those sleeves to cover up wear on the crankshaft too.

 

There are jets mounted below the cylinders that squirt oil up under the Pistons.

 

Goes to show ya you can't believe everything your told. I've been the pilot behind the 6.9 for over 400,000 miles. Love them mostly because they are so reliable.

What can cause the rear seal to go bad? This is my second motor, 100,000 miles on it.

 

Blue devil basically says why seals fail on their website ... https://gobdp.com/blog/rear-main-seal-leak-2/

 

Anything from a rough surface the seal rides on, improper installation, excessive crankase pressure due to eliminating the factory CDR system. Also severely overheating an engine can harden seals and they loose their flexibility. You never know until you look, I bought my pickup new from a dealer and within the first year or two I had an axle seal start to leak. The reason it leaked was the factory had let a big glob of black paint run onto the seal surface when they painted the rear axle housing.

 

What ever the reason for the leak I'm hesitant to do anything about it now. Sometimes it stops leaking. The engine is otherwise perfect right now. Doesn't burn oil and is giving me consistently 20 mpg.