440 rear main seal

[rowdymopar]

Has anyone had to replace a rear main seal on a 440 67' B body mine is leaking badly freshly rebuilt motor about 1700 miles on it Dont know what went wrong I'm buying the double O ring style thru Mancini Raceing . Am I better off pulling the engine totally out or can it be done in the craddle , or just slightly lifted . ??? Thanks in advance ??

 

[69 Runner]

It can be done in the car, but you have to pull the pan and rear main. Might be easier if the trans were backed up. I'm not familiar with this "double O ring" type. Got a pic of what it looks like?

 

[Meep-Meep]

Sure, the in car rear main seal replacement technique is older then dirt. I used to see "roll out pins" specifically for that purpose for sale at auto parts stores. A roll out pin is an aluminum T shaped thing that looks like a nail and the pin part goes into the cross drill of the crank (oil hole). Once it's installed you turn the crank until the flat T part makes contact with the edge of the seal then keep turning until it "rolls out" the seal. On a big block you just remove the aluminum seal retainer using a 3/8" 12 point socket unless someone put in allen screws. This technique was also used to change main bearings without removing the crank.

When you reinstall don't forget the asbestos like seals that seal the edges of the cap to the block.

 

[69 Runner]

Oops...forgot it's a B motor and the main doesn't come out.:blush:

 

[Super Stock HEMI]

ALOT Of times the problem is where the Seal Meets the Sides of the Block.One thing to make sure of is that you have enough Proper Ventalation of the CrankCase(PCV Valve etc).Too Much Blow-By will push out the seal or oil pass the seal.When Installing the REAR MAIN SEAL(Aluminum Housing)make sure you put a bead of silicone down each side of the Seal where it Joins to the sides of the block...I would venture to say your problem is exactly this.You didnt put Ultra-Copper Seal Silicone on the sides of the Seal and it is leaking passed the Adapter Seal..


SS

 

[Super Stock HEMI]

I Also Put Ultra Copper Seal In the Holes where the Bolts are for the Rear Seal Adapter.

ALSO Alot of people put the seals in BACKWARDS.When Putting the seals i make sure the OPEN Groove is Toward the FRONT of the engine.This way Pressure Build Up Will Be Able To PUSH the Seal Against the crank for a tighter seal.ALSO Make sure as to not Overtighten the pan gaskets too..Again I Install With Ultra-Copper on BOTH Sides(All Four if using a windage tray)of the gasket(s)...The Ultra-Copper Seal is the BEST and it matches the Mopar Engines Orange paint as well..

Here are a Few Examples for reference..


SS

 

[moparquest]

Rear main seal sealant

I read that 100% pure silicone is acceptable for sealing around the rear main seal side rails. Is this the same stuff that's in bathtub/tile sealer?