rear main leak

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hotrod68

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I just finished freshening up my 512 "400 base" and I can't get the rear main to quit leaking, pulled the pan put a new one in and a different seal retainer still leaks, with the car running I can watch it drip from the seal "wtf" any help?
 
hotrod68 said:
I just finished freshening up my 512 "400 base" and I can't get the rear main to quit leaking, pulled the pan put a new one in and a different seal retainer still leaks, with the car running I can watch it drip from the seal "wtf" any help?
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Is it leaking from the seal or from the retainer seals? If it is leaking from the seal, did the tension spring pop off, if not , check for crank walk or wobble. Was there a groove in the crank or a scratch?
 
Moparman1806 said:
Is it leaking from the seal or from the retainer seals? If it is leaking from the seal, did the tension spring pop off, if not , check for crank walk or wobble. Was there a groove in the crank or a scratch?
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It can also leak from too much oil or crankcase pressure
 
Are the two halves of the seal "clocked" just of a little, so that the seal can act as its own aligning portion of what takes place with that bolt on aluminium housing ?
 
Max1196 said:
Are the two halves of the seal "clocked" just of a little, so that the seal can act as its own aligning portion of what takes place with that bolt on aluminium housing ?
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did u use guidance studs to keep it lined up when installing? sometimes it will help. are u running a girdle? if so, u might want to get rid of the part that catches oil in front of the seal , that really does nothing for strength.
 
I forget where this applies... Some assemblies need a skim coat of RTV under the rear bearing cap. Without it oil can come out of that crack, more spray/flood than the seal can contain.
 
Same Issue i just bought the fast fish rear main seal kit and leak gone!
Performance-Engine-Seals

Ask for Jeff, tell him Jose from Cali sent you :) guy actually called me two weeks after to makee sure the leak was gone.
 
Make sure you have some sort of crankcase evacuation system on it or you will chase leaks forever! You need something to create negative pressure in the crankcase. I. E. A PCV valve, vacuum pump or header type of evacuation system. If you’re just running breathers it’s not enough. Breathers are designed to let air in. Not vent the gases out.
 
A breather cap doesn't have a flow check inside. It will vent. Before PVC the oily vapors were dumped in the engine bay. PVC is more of a EPA thing.
 
RedFish said:
A breather cap doesn't have a flow check inside. It will vent. Before PVC the oily vapors were dumped in the engine bay. PVC is more of a EPA thing.
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They won’t vent nearly fast enough to prevent crankcase pressure from building up. Again, they’re not intended to vent gases out, just to let air in.
If you’re referring to the old engines, pre-PCV, they had a draft tube that ran down along the engine low enough to catch the air passing by the end of the tube as you drove which caused a drafting effect that pulled the gases out from the crankcase. Hence the name “draft tube.” So even those were much more than just a vent.
 
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Rtv under and around the sides of the seal retainer cap.
The 2 composite side wedge strip, did you coat them with rtv and install them? Or did you just ditch them for straight rtv?
 
I just resolved the same problem. On the 1st round I went with the 'ol pushing in the "so called pipe cleaners" into the rtv & ended up with a slow drip. I honestly believe that most of people's problems are in the sides of the rear main bearing seal cap. I always offset the seals a bit. I personally will not do another 440 without a Mancini seal kit or a 440 source seal kit. (any of them that has the 2 rubber seals for the sides of the aluminum cap). I also found that 1 of the 2 bolt heads didn't leave much to grab a hold of (even though it's only 30 ft/lbs). So I went with allen bolts.
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Yep, I rtv'd the sides, corners and the slots where the seals sit.
 
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I think when u use the factory seal retainer u should mill off .010 off the ends to make it flat and level and to give it a little more crush. I seen a thread on that somewhere, but I couldn’t find it. Kim
 
oldkimmer said:
I think when u use the factory seal retainer u should mill off .010 off the ends to make it flat and level and to give it a little more crush. I seen a thread on that somewhere, but I couldn’t find it. Kim
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Ye, I went in that direction using fine sandpaper and a pc. of glass (flat surface) I wasn't taking any surface to chance. I may have taken .001. of the mating surface.
 
josekh7 said:
Same Issue i just bought the fast fish rear main seal kit and leak gone!
Performance-Engine-Seals

Ask for Jeff, tell him Jose from Cali sent you :) guy actually called me two weeks after to makee sure the leak was gone.
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I used the same along with the Mancini billet retainer.It did the job. I also welded up the crank because mine was on the low side where the seal sits. All in all it was a pain but finally stopped leaking. And yes the fastfish one piece seal that Jim sold me worked great. On a side note the seals we get today are very different than the old ones. I compared it and the old ones had more "MEAT" on them. I guess production got cheaper.
 
I don't know guys, that seal contact area on the crank looks pretty nasty.
 
Try installing the seal at the 6 & 12 oclock position. Then slide the seal retainer down over. With it in place drop your bolts in. If they interfere at all with your retainer you'll need to open the that hole on the retainer that is making contact and that is likely what is causing your seal to leak. When you installed your seal at the separating line and bolt your retainer into place it moves and the edges of your seal is now not meeting.

On my 505 I had installed my seal with the ends of the seal at the separating line. On the dyno it dribbled oil like a bugger and made a real mess of my new TTIs. I replaced the seal and installed it as I described at the 6 & 12 position with a slight wipe of Right Stuff on the seal ends. I used right stuff along the sides of the retainer as well and back together. No leaks so far with a full season at the strip. I actually got this method from a member here on FABO, who has used this method for decades. I forget his name though.
 
Are you 100% sure it's not a marine crank? It will be hashed for reverse rotation in the seal area and you will never get it to seal.
 
Mike Alexander said:
Try installing the seal at the 6 & 12 oclock position. Then slide the seal retainer down over. With it in place drop your bolts in. If they interfere at all with your retainer you'll need to open the that hole on the retainer that is making contact and that is likely what is causing your seal to leak. When you installed your seal at the separating line and bolt your retainer into place it moves and the edges of your seal is now not meeting.

On my 505 I had installed my seal with the ends of the seal at the separating line. On the dyno it dribbled oil like a bugger and made a real mess of my new TTIs. I replaced the seal and installed it as I described at the 6 & 12 position with a slight wipe of Right Stuff on the seal ends. I used right stuff along the sides of the retainer as well and back together. No leaks so far with a full season at the strip. I actually got this method from a member here on FABO, who has used this method for decades. I forget his name though.
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I've read that too but I'm not really getting how to seal the sides on the retainer with Right Stuff, does it mean that you use RS in the slot where the side seals should be or do you seal it on the inside or outside of the retainer?
My plan is to change seals with engine in the car just removing the oil pan, not so fun but I've seen it done by others.
 
Zwap said:
I've read that too but I'm not really getting how to seal the sides on the retainer with Right Stuff, does it mean that you use RS in the slot where the side seals should be or do you seal it on the inside or outside of the retainer?
My plan is to change seals with engine in the car just removing the oil pan, not so fun but I've seen it done by others.
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I was able to still use the side seal strips with the retainer while clocking the seal at 6&12 oclock. I have heard that sometimes you might not be able to get them on both sides. Even with the side strips I used right stuff on the retainer to the block as a double protection. If for some reason there's not enough room for one or both side strips just use right stuff on both sides of the retainer. Make sure the block and retainer are clean clean clean and no oil residue before applying RS. Brake clean should clean things up good for you. Doing the job in the car will be harder than on the stand, just more awkward. Good luck!
 
your never going to stop a big block mopar rear seal from leaking,while do you think they put drip pans under them at the dealership
 
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