Rear Main Seal Leak - Other Possibilities?

[PurpleBeeper]

70 440 4spd car. I've got oil gushing out of the bellhousing (qt/30 miles). Definitely oil, not trans gear lube. Top of bellhousing is dry. Oil sender and back of both valve covers dry too.

Well, I replaced the rear main seal/side seals (old ones didn't look bad) and it's still gushing oil from the bellhousing. Where else could a 440 be leaking oil back there and how do I diagnose and fix it??? Thanks for help in advance!

 

[1967coronet440]

oil pressure sensor is back there, assume you checked that...

 

[69L48Z27]

Rear cam plug. Isn't there also 2 oil gally plugs back there?

 

[The Capitan]

Excessive crankshaft endplay can cause the rear seal to leak.

 

[Fran Blacker]

There's only oil pan and gasket, rear main, side gaskets on seal an 2 plugs in back of block. Unless somebody didn't tighten plugs or left them pretty loose. I had a plug leak, my fault, because I didn't really tighten it. To remove the one that was in there the machine shop drove a torx socket/bit in it to remove it. I was a little gun shy on tightening it. * hours to pull engine an put it back in, I test engies for leaks before putting them in.

 

[PurpleBeeper]

All good tips.1.Did check oil sender and it is dry. 2. How much oil could leak from excessive crank endplay? This is A LOT of oil. 1 qt/30 miles is no exageration at all. 3. I guess the rear cam seal (looks like a freeze plug, right? OR oil galley plug(s) are my only options left, correct? Please jump in here.

So, can i get the rear cam seal AND the oil galley seals by dropping the trans, removing bellhousing/clutch/flywheel?

Can I tighten the oil galley plugs that way? Also, can I install a rear cam seal that way (will I have room)?

Anyone with experience with these please chime in. Thank You

 

[moper]

Yes - only four sources of oil in the bellhousing: (2) lifter galley pipe plugs (full pressure oil 100% when engine's running); cam plug (splash fed oil from the rear cam bearing); and the rear main (splash fed from sump). My money is on the pipe plugs if it's really that fast.

 

[Dibbons]

I just went thru this, see my thread "Leak Detection Using Smoke and Mirrors":
http://www.forabodiesonly.com/mopar/threads/oil-leak-detection-using-smoke-and-mirrors.386411/

 

[PurpleBeeper]

Yes - only four sources of oil in the bellhousing: (2) lifter galley pipe plugs (full pressure oil 100% when engine's running); cam plug (splash fed oil from the rear cam bearing); and the rear main (splash fed from sump). My money is on the pipe plugs if it's really that fast.

Well, the motor is in the car... lifter oil galley plug is the winner (or loser I guess). I vaguely recall putting some teflon tape on those when I had the motor out... hex bolts, right? And sort of near the back cam plug, looks like a freeze plug right?

Yes... it IS gushing that much oil. Maybe one I didn't tighten too well vibrated & backed out... dang it... but at least I'm on the right track.

So here's thinking out of the box.... IS it possible to just loosen the bellhousing & slide it back 1" and get a long allen wrench in there? Or am I just dreaming & I have to drop the trans?

 

[mopar 3 B]

Flywheel is going to be in the way. Sorry its all got to come out. More than likely the clutch has been oil saturated by this time. Replace the disk and clean everything.

 

[toolmanmike]

Well, the motor is in the car... lifter oil galley plug is the winner (or loser I guess). I vaguely recall putting some teflon tape on those when I had the motor out... hex bolts, right? And sort of near the back cam plug, looks like a freeze plug right?

Yes... it IS gushing that much oil. Maybe one I didn't tighten too well vibrated & backed out... dang it... but at least I'm on the right track.

So here's thinking out of the box.... IS it possible to just loosen the bellhousing & slide it back 1" and get a long allen wrench in there? Or am I just dreaming & I have to drop the trans?

Sucks! Use pipe thread sealant and not teflon tape.

 

[NOSTRT980]

I had to remove the motor for what I thought was a rear main leak. it turned out the machine shop put the cam plug in crocket causing a leak.

 

[Kern Dog]

Rear cam plug. Isn't there also 2 oil gally plugs back there?

I had a persistent leak back there that turned out to be loose oil galley plugs! I pulled them out, cleaned them up and screwed them back in with Gaskacinch. No more leaks!

 

[PurpleBeeper]

Flywheel is going to be in the way. Sorry its all got to come out. More than likely the clutch has been oil saturated by this time. Replace the disk and clean everything.

I thought about that and the clutch is feeling good. I'm hoping the block plate on the Lakewood scattershield has kept the disk clean, but I will spray it with carb cleaner at least. I'm totally strapped for cash now & I'm running a Centerforce. I don't think i can buy just the disk

 

[66Satellite47]

All really good input. My 2 cents drop the trans, pull the flywheel, get a good look. Either cam plug or (more likely in my op the galley plugs).

 

[Fran Blacker]

I thought about that and the clutch is feeling good. I'm hoping the block plate on the Lakewood scattershield has kept the disk clean, but I will spray it with carb cleaner at least. I'm totally strapped for cash now & I'm running a Centerforce. I don't think i can buy just the disk

I'd use Brake clean read in Center Force directions carb cleaner leaves a residue .

 

[PurpleBeeper]

I'd use Brake clean read in Center Force directions carb cleaner leaves a residue .

Thanks Fran. Good news is that I did find out I can buy JUST the Centerforce dual friction disc, so that helps.

Also, I believe Centerforce is wrong about (most) carb cleaners. In most cases, both brake cleaners & carb cleaners are "paint thinner in a spray can" (solvent). I'm over-simplifying here a little bit, but my company makes a couple different carb cleaners & about 10 brake cleaners. All traditional "solvents" evaporated & don't leave any residue. There are MANY different blends of both. One thing I'm concerned about is that the same solvent(s) that remove engine oil "might" damage clutch friction material OR (more likely) make the oil migrate further down into the friction material just to slowly seep out later. If it were a race-only metallic disc clutch I'd hose it with solvent & not give it a second thought.

 

[Fran Blacker]

Thanks Fran. Good news is that I did find out I can buy JUST the Centerforce dual friction disc, so that helps.

Also, I believe Centerforce is wrong about (most) carb cleaners. In most cases, both brake cleaners & carb cleaners are "paint thinner in a spray can" (solvent). I'm over-simplifying here a little bit, but my company makes a couple different carb cleaners & about 10 brake cleaners. All traditional "solvents" evaporated & don't leave any residue. There are MANY different blends of both. One thing I'm concerned about is that the same solvent(s) that remove engine oil "might" damage clutch friction material OR (more likely) make the oil migrate further down into the friction material just to slowly seep out later. If it were a race-only metallic disc clutch I'd hose it with solvent & not give it a second thought.

There maybe one brand of card cleaner that leaves a residue so they say don't carb cleaner. JMO. They wouldn't put a name out there.
Is the leak in oil gallery plug?

 

[PurpleBeeper]

There maybe one brand of card cleaner that leaves a residue so they say don't carb cleaner. JMO. They wouldn't put a name out there.
Is the leak in oil gallery plug?

I haven't pulled the transmission/clutch/flywheel yet, but based upon the pure volume of oil & the help from members on this site, I'm pretty darn sure it's an oil gallery plug. I "think" I got some with a freeze plug kit & put them in "just because"...pretty sure that was a bad move.

As for carb/brake cleaner residue... You might get some residue if something like acetone (aka California anything in a spray can) or maybe even toluene/xylene dissolving the clutch material (creating your residue). I guess you "could" have some ultra-slow evaporating mineral oil or very high flash point naptha (more like an oil than a solvent) in a carb/brake cleaner that would evaporate so very, very slowly that it would leave a residue, but I've never seen that in a carb/brake cleaner formula...not that it couldn't exist, I just haven't seen it.

Honestly, if I knew for sure a toluene/xylene (both evaporate fast) wouldn't attack the friction material of the clutch, I'd just soak my disc in it & spray it off a few times with even more. I wouldn't give it a second thought.

 

[5.7 hemi]

Acetone!