B Engine rear main seal leak repair options.

[bherman]

Hello All, recently I started and performed the break-in process on the "new" engine for my project car. Unfortunately I have a rear main seal leak. I'm trying to determine if it's possible to replace the seal in the car and without dropping the crank. I've been told this can be done successfully but I have no idea if this is a real possibility or just a waste of time. I would appreciate your thoughts and opinions, thanks, Brian.

 

[snakeoil24]

Yes you can do it in the car. Lisle makes a tool to remove and install. You will need to check if seal holder bottomed out before the seal ends crushed together. If the retainer bottomed out before the seals crushed together then your going to need to mill the bottom of the retainer. Also it might sound silly but what direction did you have the lip of the seal facing?? should face toward front of engine.

 

[747mopar]

I don't see why it wouldn't be possible, working space will be the fun part with the seal being up in the block. Have you cleaned it super good and checked it really often to make sure it's not leaking out of the sides of the lower seal support? They can be a bare to get sealed sometimes and would be a lot easier to fix. Positive crankcase ventilation is always one thing to look into as well. Good luck

 

[727]

Have done it several times. Be sure car is elevated high enough and that it is safe to work under.

 

[Jason69 RR]

I did it last year. Again make sure the car is up high enough. Drop the steering, pull the pan..... Good Luck!

 

[Jason69 RR]

 

[PurpleBeeper]

I've done it too. As Jason noted, use a hammer or pickle-fork to detach the steering "drag link" at the Pitman arm & idler arm (won't affect alignment). Drain & drop the pan. Remove the 12-point bolts on the seal retainer & remove. Use a plastic/wood piece of something (no crank scratches) & push the top 1/2 of the seal around the crank until it's upside down & remove it. Make sure seal is pointed the right direction (lip forward sounds right) & reverse directions to install. I like to use some RTV on top of the side seals. You can do it in one day.

 

[bherman]

Yes you can do it in the car. Lisle makes a tool to remove and install. You will need to check if seal holder bottomed out before the seal ends crushed together. If the retainer bottomed out before the seals crushed together then your going to need to mill the bottom of the retainer. Also it might sound silly but what direction did you have the lip of the seal facing?? should face toward front of engine.

snakeoil24, first thanks for your reply and the information. I purchased the short block assembled so I'm not sure the seal is installed correctly. I looked at the Lesle removal/installation tool and it looked like the corkscrew removal tool would work, but it seemed to me that the clips on the cable installation tool would damage the seal when pulling it in place. Does that tool work for a split type seal or is it for a rope seal? Thanks again, Brian.

 

[bherman]

I don't see why it wouldn't be possible, working space will be the fun part with the seal being up in the block. Have you cleaned it super good and checked it really often to make sure it's not leaking out of the sides of the lower seal support? They can be a bare to get sealed sometimes and would be a lot easier to fix. Positive crankcase ventilation is always one thing to look into as well. Good luck

Hi 747mopar, thanks for your reply. I really don't know where it's actually leaking, it could be leaking at the side seals or maybe at the pan rail on the seal retainer. I have to pull the pan either way and I just wanted to be ready for whatever I found. Good thought on the crankcase ventilation I hadn't considered that! Thanks, Brian.

 

[bherman]

Have done it several times. Be sure car is elevated high enough and that it is safe to work under.

727, thanks for your reply. I'm lucky the vehicle is on a hoist, Brian.

 

[bherman]

I did it last year. Again make sure the car is up high enough. Drop the steering, pull the pan..... Good Luck!

Jason69 RR, thanks for your reply. This car is a restomod, so I don't have to drop the steering link but I do have to drop the rack. Thanks, Brian.

 

[Yatzee]

Hello All, recently I started and performed the break-in process on the "new" engine for my project car. Unfortunately I have a rear main seal leak. I'm trying to determine if it's possible to replace the seal in the car and without dropping the crank. I've been told this can be done successfully but I have no idea if this is a real possibility or just a waste of time. I would appreciate your thoughts and opinions, thanks, Brian.

Good luck changing it with the motor in the car. Been there done that! Consider the new style rear seal and holder that's out there but don't deviate from the instructions or you'll be doing it twice or maybe three times.

 

[HEMI-ITIS]

SUPERPERFORMANCE make a great gasket and seals!!

http://www.superformanceproducts.com/
AND,,,,,,he a MOPAR guy!!

 

[coloradodave]

Also, use a mirror and a good light to check the valve cover gasket area for leaks. The oil loves to leak from there, run along the pan rails and drip /run down from the back of the pan/bellhousing area. Just went through this with mine...

 

[727]

Make sure your oil pressure sensor isn't leaking. Oil runs down where it looks like the real seal is leaking.
Also had the freeze plug at the rear cam bearing leak and it appeared that the rear seal was leaking

 

[bherman]

Hi Yatzee, thanks for your input. Sounds like you've had fun doing one of these before...LOL. When you say "new style seal and holder" could you clarify? I do have a billet holder and I was aware that the seals are produced in different materials but I'm unaware of any improvements past that. Do you have a recommendation? Thanks again, Brian.

Hi HEMI-ITIS, Thanks for the tip! I'm assuming that you have used their products and were happy with the results. Thanks again, Brian.

Hi coloradodave, 727, you guys' must be psychic. The valve covers were leaking and although I don't have a sending unit at the back of the block, one of the external feed lines for the heads was leaking in that location. I've managed, I hope to fix those locations but I'm still leaking in the vicinity of the rear main. Thanks for your input, Brian.

 

[coloradodave]

I recently changed my rear seal retainer (Mancini) to one from Hughes Engine (hughesengines.com). The improvement in the side seals, a new seal material and a different idea on the machining of the retainer all helped me make that decision. If you go to their site they have a very detailed set of instructions to follow to make sure your motor doesn't leak from there. The motor was in the car and there was no need for any special tools, as long as you're not installing a rope seal. Did not loosen any main caps other than removing #5 for clearance to change the seal. Worked for me...

 

[not so famous bob]

went thru this on my 505, be double sure to set up a pcv valve on it !

 

[Darthomas]

For quick fix, plug oil cap , dipstick.
Draw vacuum from the PCV of a running engine on another vehicle pulled up nose to nose.
Now, while the running engine sucks a tremendous vacuum on the leaky engine, you can put a piece of hose in your ear and quickly find where air is being sucked in.
Then you use that vacuum to pull the RTV sealant into the gap.

I put an extension tube onto the RTV snout and put it up into the rear main seal, when I had about a quarter inch of crank end play. Good until rebuild many years later. Not a drop.

 

[Cranky]

Make sure your oil pressure sensor isn't leaking. Oil runs down where it looks like the real seal is leaking.
Also had the freeze plug at the rear cam bearing leak and it appeared that the rear seal was leaking

Bought a 69 319 Dart in the mid 70's for cheap because of this. The guy thought it was a rear main and I couldn't tell with the car on the ground so I took a chance and it paid off. Great running car with automatic, AC and PS. It's unreal how bad a sensor can leak!

For quick fix, plug oil cap , dipstick.
Draw vacuum from the PCV of a running engine on another vehicle pulled up nose to nose.
Now, while the running engine sucks a tremendous vacuum on the leaky engine, you can put a piece of hose in your ear and quickly find where air is being sucked in.
Then you use that vacuum to pull the RTV sealant into the gap.

I put an extension tube onto the RTV snout and put it up into the rear main seal, when I had about a quarter inch of crank end play. Good until rebuild many years later. Not a drop.

Wow, that's one I've never heard of before! Guess a vacuum pump wouldn't pull enough volume??