Leak-free rear main install.

SS_Sean

Pro Bracket
Joined
Jul 10, 2006
I'm going to roll some bearings into my motor with the motor in the car. Not the most optimal way, but that's how I gotta do it. Any suggestions on installing the rear main so it does not leak? Can I reuse the seals that run down each side of the cap? Looks like there was a thin film of RTV in there, and it didn't leak when I pulled the pan and cap.
 
Any suggestions on installing the rear main so it does not leak? Can I reuse the seals that run down each side of the cap? Looks like there was a thin film of RTV in there, and it didn't leak when I pulled the pan and cap.

replace the seal and put in new "right stuff" in the side channels and top of of the main cap.


Did you spin a bearing?
 
No, got some grooves in the main bearings, not bad, but they are there and shouldn't be. The rod bearings actually look better than the mains, but it's clear that debri did go through the motor.

What's this 'right stuff' stuff?

Also anyone know the torque spec on the mains? I've got an ARP stud kit in there. how about the ARP rod bolts?
 
after installing the main cap and new neoprene rear main seal (with sealer on the sides not the provided straight rubbers) let the car sit overnight before starting. IMO this is key to avoid leaks. The sealer usually dries in a few hours however takes several hours to cure.
 
Anyone have the torque specs?

torque specs are here

Bolt Torque Explained


When i do the rear main seal i leave the side pieces out and fill the cavities with clear rtv and insert dampened pipe cleaners into the rtv to help it cure,i leave them in there also. It helps also to rotate the seal a 1/4'' in on one side so that it isn't even with the main cap and block mating surfaces,then put just a thin smear of rtv on the main cap and block when you do the final install and torque to spec.

John :smile:
 
When I do the rear main seals, I use the rubber strips. After install they need to be trimmed down not to interfere with oil pan gasket. I coat the rubber strips with gray/black RTV or Right Stuff. Then install the correct "nails"

On the actual seal, I install them offset from the parting line of the block. One edge is sticking up about 1/4" and the other end is down. Install the other piece opposite in the cap. Also make sure you install the seal in correct direction.

I use an anaeorbic sealer between the cap and the block. The anaeorbic sealer does not need oxygen/humidity to seal like RTV does.
http://www.permatex.com/products/Automotive/automotive_gasketing/anaerobic_gasket_makers.htm

Also clean all the metal surfaces with brake cleaner or laquer thinner. I prefer laquer thinner.

Billy T.
gnxtc2@aol.com
 
About the rear main seal replacement

I use an anaeorbic sealer between the cap and the block. The anaeorbic sealer does not need oxygen/humidity to seal like RTV does.
http://www.permatex.com/products/Automotive/automotive_gasketing/anaerobic_gasket_makers.htm

Also clean all the metal surfaces with brake cleaner or laquer thinner. I prefer laquer thinner.

Billy T.
gnxtc2@aol.com

Regarding the rear main seal replacement into GN 87, there is the recommendation into discussions to use the anaerobic sealer in the bearing cap surfaces- the surface areas, where are also the bolt holes; for instance Permatex 518 as stated in some message. I haven´t the possibility to get the stuff in Europe for some reason(of course the thread locking and bearing locking stuff, wich are also the anaerobic ones).

So, my question is, what sealer is the substitute for the anaerobic one into that area, same Permatex Ultra Black silicone(wery slight layer in to that area), which I will use on the side cavities or how?

Thanks in advance!
 
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