Any Solution to Dripping Rear Main??

[GetX'd]

Hi guys - I thought I had a dripping oil pan because the bolts were a little loose back when - I tightened them after I put the engine in the car. A while later I noticed a slight drip on the garage floor. Today I got it to a shop where I could get it up on a lift - it seems as though I have a slow leak from the rear main seal. The motor has only got about 2000 miles on it. Which is neither here nor there - I'm just wondering if there's a solution besides the dreaded pull everything out to put in a new seal. I've heard there are additives that you can add to your oil that may or may not stop the leak.

I don't know if that's something to try - if it would gum up the fresh motor - or not. It's a 440 Automatic. Anyone have any ideas?. Not sure what to do. The motor builder is in another state so I'm sol as far as getting him to help. Ideas??

 

[BeeKool]

That sucks.

 

[69L48Z27]

I'm not a fan of additives.

Only advice I have is make sure it's the rear main before digging in. Valve covers, heads, caller cover, and sending unit looks like RMS leaks sometimes.

 

[5.7 hemi]

My 383 leaked at all 4 corners of the valley pan and I thought it was the rear main. May want to check into that.

 

[Dreamcatcher]

I am not a fan of additives but I think Lucas makes something like that. I think I trust their stuff far over everyone else's. Good luck.

 

[HT413]

I had a leaky oil pressure sender once that I swore was a rms leak. Oil came out fresh and clean from the sender so it was almost invisible until it made its way down the block picking up dirt.

 

[GetX'd]

I checked all the top shelf stuff - or I should say I had a speed shop do it. They're convinced it's the RMS. Of course I know they also get a big paycheck if I had them fix it. But the drip is so small I'm not going to do anything drastic just yet. I remember the engine builder had trouble getting it to seal in the first place. Tried several of the highly touted seals that didn't work. I recall he told me in the end he went with the old fashion rope seal. (We're above my pay grade now) and got that to seal. I'm bummed - but not surprised it's now leaking. If that's what it is.

I called Oreillys and they said they have this stuff called Blue Devil Rear Main Seal stop leak. The guy at the speed shop said he used it on a car once - and it never leaked again. I get most of you don't like the idea of additives - but do you think I'm hurting anything trying that product? I'm out of my league here with trying to fix something like this - and yeah I'm kind of wanting to try the easy way out. But on the other hand if I'm risking anything I won't do it. A few drips here and there aren't going to kill me. I just don't want to harm the engine. Do these seals ever blow out completely?

 

[Billccm]

I'm probably going to hijack the thread, but drips don't bother me too much. I do not believe I've ever had a B Body Mopar that didn't leak a little (including the trans). If it's just a spot on the cardboard under the car and not a puddle, and you don't see the dipstick level falling fast I'd wait awhile and just keep your eye on things. I'm also not anti additive as I use Lucas ZDDP, StaBil products, etc, but you may want to ask around about the Blue Devil stuff. PurpleBeeper on this forum is a chemist and might have some insight as to what the product contains and the advantages and disadvantages.

I also vote for the rope seal as my luck was not very good on my previous big block mopar with the two piece seals.

 

[5.7 hemi]

If you have a rope seal on a polished (smooth) crank, it's gonna leak.

 

[Dennis H]

Agreed on comments. Valley pan leak could be deceiving. Have a Mopar savvy person do the repair. Mine does not leak because the guy who put it in did it many times and knows what he is doing. Mopar guy.

 

[5.7 hemi]

Bring that bad *** up to my place and I'll fix it for ya. It's only about a 4 hour drive, and you'll be happy with the out come.

 

[GetX'd]

Bring that bad *** up to my place and I'll fix it for ya. It's only about a 4 hour drive, and you'll be happy with the out come.

Hemi - where is your place? If it is a leaking RMS what's a ball park on cost to fix? I don't know if I could drive that car that far - it is a beast and I don't know how I'd work the logistics.

 

[5.7 hemi]

Sending pm.

 

[Dennis H]

Hemi - where is your place? If it is a leaking RMS what's a ball park on cost to fix? I don't know if I could drive that car that far - it is a beast and I don't know how I'd work the logistics.

Let me know when you go. I have something for 5.7 too. I'll meet you there.

 

[5.7 hemi]

I haven't forgotten ya Dennis!

 

[kiwigtx]

Hemi - where is your place? If it is a leaking RMS what's a ball park on cost to fix? I don't know if I could drive that car that far - it is a beast and I don't know how I'd work the logistics.

Fill the tank with gas, jump in, and follow the road directions. Should be straight forward.
Top man @5.7 hemi for making a very cool offer to help.

 

[rgp266]

Mopar Performance used to make a special grooved rear main bearing that routed the oil to the crank side of the main for better drain back. I have used them on several builds and never had a rear main seal leak.

Bob

 

[Dibbons]

That "special" grooved main bearing mentioned above, for big blocks only or available for small blocks, too? Part #?

 

[SlinktRR]

PurpleBeeper on this forum is a chemist and might have some insight as to what the product contains and the advantages and disadvantages.

That makes at least two chemists here then, very cool. My opinion is stop leak additives for a crankcase leak are not worth the risk. Radiator, maybe if you were out in the Mojave desert overheating losing coolant through a pinhole and had to get to the next town. No way for the lifeblood of your engine.

 

[BeeKool]

Not an engine that freshly overhauled.
I've used stop leak in old motors that I wanted to get another year or two from. (No point in overhauling an engine in a truck that yoy paid 200$ for) had varying levels of success. I think the Lucas products worked best.
But with your engine I would consider taking 5.7 Hemi up on his offer. Cuz your entire uncarriahe is going to get covered and grimy and your exhaust too and your ride will smell like an old leaky Detroit before long.