Rear engine seal replacement

E

eagleguy

Member
Joined
Apr 5, 2015
Searched for some threads but found none. I am looking for the best way and type of rear engine seal to use to replace mine. It is my understanding that as the seal is two piece even the replacement will leak.
 
hard to believe you couldnt find anything?? ..try google and add turbobuick works great
heres one http://www.gnttype.org/techarea/engine/rearmain.html

heres my go at it

factory is rope , replace with felpro neoprene BS4o613
a for best way , really only one way and its lotsa fun ..
get car on a lift ,
remove crossover pipe and converter shield
drain and drop oil pan.. lotsa fun..its tight fit with stock old motor mounts and you may need to raise engine a little and rotate crank to get pan out
pull rear main bearing cap ..mo' fun
pull block half rope seal from block ( more fun dont scratch crank ) they sell a sneaky pete for this but ive never had to use one , push seal in on one side grab seal at other side with needle nose pliers
clean block sides and face , hit with blast of brake clean to get rid of any oil
slide the new seal half into the block around the crankshaft
clean main cap thoroughly ( dont damage the bearing shell) , install new seal half into cap and apply RTV sealer to side cavities and a smear on cap face , put some assembly lube on bearing face ..dont dilly dally , reinstall main cap being careful not to knock the bearing shell loose
torque cap bolt to spec
squeeze more sealer up into side cavities until it comes out the corners at top
clean up pan and pan rail of block ,
install pan with new pan gasket
replace crossover and converter shield
fill with oil and prime engine before firing (disconnect ignition module , pull spark plugs , crank and verify oil pressure )
replace plugs and fire up
 
Last edited:
I was told by a local mechanic the seal is a two piece unit and because of that the job only requires the removal of the inspection shield for replacement. What gives? He has inspected the car and told me about the seal but would not warrant the work.
 
well you dont have to drop the transmission and remove the flywheel as you do on some cars but wont help much on a buick except to give more room to pull the pan off
you do have to remove the shield and the crossover pipe and the oil pan and the rear main cap to get to the seal
 
Pacecarta, are you saying use silicone instead of the rubber side cap seals with metal pins?
 
pacecarta said:
yes and no... rightstuff RTV not silicone, I dont use the rubber sidee seals and pins ,
Click to expand...

If you use silicone and I have many times it needs to the ULTRA line that permatex has I think the gray was the best, it is much more oil resistant than the regular stuff.

What have you found with the right stuff pacecarta?
 
On my latest build I offset the seal 1/4 inch. My crank does not have knurls on the seal surface and it has always leaked in the 3 engines it has been in with the seal installed flush. It does not leak a drop now with the seal offset. I never use the side seals and pins, just fill the cavity with aerosol Right Stuff until it oozes out of the cap sides. Advance auto Parts and Pep Boys sells it.
 
Cool mine is leaking a few drops now n then I don't Move car a lot but that drop on my floor every now and then bothers me thanks
 
ultra black is the same as rightstuff ..same people make it... permatex .
difference is the ultra has a looser consistency, smoother flowing . i use the ultra for paper gaskets
the rightstuff is thicker and can be put to use sooner without fear of it pushing out
either are good where theres oil

as to the 1/4 turn being what fixed your leak ..most of the leaks thought to be rear main usually end up being valve covers or intake rail seals
 
The leak was the rear main seal for sure. Valve covers and intake were always dry. I measured the offset of the halves with a dial caliper and set them at .250.
 
Like others have mentioned I always rotate the seals the ends don't line up with the cap.
 
I've done over 30 of these in the last year with zero leaks. What Paul is describing is the way to go. Pull the pan, pull the cap, and fish out the upper piece. I prefer to use a drywall screw. I screw the drywall screw into the rope seal and then push from the opposite side with a small screw driver and pull on the dry wall screw with pliers. I've never had this technique not work if the seal hadn't been tampered with and ripped apart. Then 100% clean with solvent and smear a thin layer of rtv on the mating surface of the cap and install. Use a caulk gun with rtv and inject the rtv into the cavities when assembling. Go until you see the rtv ooze out from the gap inside and outside and you're done with the seal install. It's worth adding another drain plug to the bottom of the pan at this time to get more of the oil out on oil changes. Be sure you are running a stock baffled pan. I've seen 3 in the last year with no baffle. Guaranteed to suck air when launching the car. I also prefer to use the rubber pan gasket for non girdled engines. The surfaces need to be 100% oil free and dry. Use the supplied plastic locating pins when installing the pan to keep the gasket in place. Don't over tighten the pan gasket to where it is squeezing out the sides of the pan. No rtv on the gasket! If you use a cork gasket you will not need sealant either but will need a few re-torques. If you use the cometic hard fiber gasket you will probably need sealant. The gasket is so hard it doesn't like to conform to irregularities in the rail.


Sent from my iPhone using Tapatalk
 
pacecarta said:
caliper ..really? ..thats just silly
Click to expand...

So what happens if one end is above the block or cap more than the end of the other half ? If the seal slides so the ends are even your lucky, if not, messed up seal and you can't see it. I used the sliding depth bar to get it right.
 
pacecarta said:
hard to believe you couldnt find anything?? ..try google and add turbobuick works great
heres one http://www.gnttype.org/techarea/engine/rearmain.html

heres my go at it

factory is rope , replace with felpro neoprene BS46013
a for best way , really only one way and its lotsa fun ..
get car on a lift ,
remove crossover pipe and converter shield
drain and drop oil pan.. lotsa fun..its tight fit with stock old motor mounts and you may need to raise engine a little and rotate crank to get pan out
pull rear main bearing cap ..mo' fun
pull block half rope seal from block ( more fun dont scratch crank ) they sell a sneaky pete for this but ive never had to use one , push seal in on one side grab seal at other side with needle nose pliers
clean block sides and face , hit with blast of brake clean to get rid of any oil
slide the new seal half into the block around the crankshaft
clean main cap thoroughly ( dont damage the bearing shell) , install new seal half into cap and apply RTV sealer to side cavities and a smear on cap face , put some assembly lube on bearing face ..dont dilly dally , reinstall main cap being careful not to knock the bearing shell loose
torque cap bolt to spec
squeeze more sealer up into side cavities until it comes out the corners at top
clean up pan and pan rail of block ,
install pan with new pan gasket
replace crossover and converter shield
fill with oil and prime engine before firing (disconnect ignition module , pull spark plugs , crank and verify oil pressure )
replace plugs and fire up
Click to expand...

I cannot find the Fel Pro seal # BS46013. Can you tell me where to buy it?
 
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