Rear Main Seal Photo/Video Request

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SoCal
My Car
73 Mustang Convertible
Born an I-6, spent the teenage, 20 and 30 years as a 302, but at 40 will reach full potential as a 351C.
I thought someone had posted a video/photo of the venerable 351C two piece rear main seal install. Didn't come across one in the search. Perhaps someone can enlighten me in this regard.

Outside of that, I believe the key is to:

0. I guess most people like to spend $30 for a pair of seals....

http://www.summitracing.com/parts/cgt-c5689 because the ones in the kit are crap...I guess....

Are they really crap? Do I really have to spend $30 for .05 oz of VITON????

No, I am not remachining my block for a one piece seal. What is that, like $50 to machine + the one piece seal cost. Is it really that hard to keep the oil from leaking out the rear? I mean, I don't want oil leaking like everyone else, but come on.

1. Offset the seals so the ends or not fully covered by the seat by like 1/8-1/4 of an inch.

2. Dab some RTV onto the ends of the seal- 2 top, 2 bottom, 4 total.

(Not sure which RTV to use(red, blue, black, gray, high temp, blah blah blah:

http://www.permatex.com/products-2/product-categories/gasketing/gasket-makers

ugh.)

3. Say a Hail Mary...respectfully mind you.

4. Align and mash.

5. When you realize you didn't carefully match the offset ends of the 2 piece seal, remove $30 seals, and install the second set you bought because you were smart enough to know you would be stupid enough to not carefully match the offset ends the first time around.

 
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Not everyone offsets them. Overly offsetting them may make them bind when tightening down the cap. When you have to pull the transmission and drop the pan to fix it, you'll never buy the standard seal a second time. Just finished mine up and started it today after it has been torn down for the last 3 weeks. Permatex Red RTV gasket maker is a good product in this application and was recommended to me by a mechanic with many years of high performance engine building experience. It is primarily to keep the gasket from slipping or turning.

Don't forget to remove the locating pin in the main cap.



After 45 minutes not a drop of oil was seen.

 
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Rear Main seals should not present a problem to an attentive assembler, but, there are a few things to know here.

1) Yes, by all means, use a small pin punch to drive the rope seal slippage pin out of the cap to use a rubber seal. Just a small dot of silicone inside the seal groove will seal the hole.

2) If the crank is out, inspect the surface that the seal rides on...you may find that the factory knurled serrations into this surface to work with a rope seal. These serrations must be polished down so that they don't chew up the rubber seals. This is commonly done after the crank is ground and gets a final micro-polishing, if the crank grinder is heads-up.

3)Most replacement rubber main seal halves will fit snug enough to not warrant using any silicone in it's seating groove. For me, it's a feel thing that tells me. If you'll sleep better, then go ahead, but use a tiny bead, and only on the outside circumference.

4) Run a dab of white grease with your finger all around the crank's surface where the seal will contact. You do not want the seal to run dry against the crank.

5) Install the seals. I have 25 years on my personal car with the ends flush with the sides, and no leaks...however I have staggered the ends 1/8 to 1/4 from the parting line as a rule for years now on customer's engines just to CYA, with similar no-leakage results. Be aware that the seal halves have a right and wrong facing direction. The seal must be installed with the lip forward, towards the oil and crankcase pressures. Installed correctly, the crankcase pressure will help force the seal against the crank's surface.

6) Prior to installing the rear main cap, I run a very thin line of silicone across both sides of the rear main cap's underside, from the seal groove out, to where the pan seal notch is. this will keep any oil from seeping out under the cap.

7) I do not use common silicone from a squeezable tube, and don't recommend the "blue" or ever the "hi-temp red". The BEST by far is Permatex's black"The Right Stuff" which is used in a 6" caulking gun form. Do not use "The Right Stuff" that comes in a squeeze tube, or the pressurized can. You can control the bead and amount using the caulking gun method and pointed tip. Once cured, the "Right Stuff' is more like vulcanized rubber and more chemical resistant than silicone. If any out there want to try a side by side test of The Right Stuff verses the common tube silicone, you'll find it's rightfully named. This is not the only place that this product is superior. When you install the intake manifold to the engine, you are going to throw away the cork, or rubber end seals that come with the intake gasket set ( YES, you are ). Using the 6" caulking gun enables you to precisely lay a perfect layer of sealant onto the block to seal the block's valley to the manifold's undersides and corners. I always set the manifold on, prior to sealing, to visually get a sense of how thick a bead will be necessary, then remove the manifold and lay the bead. Use the caulking gun of TRS to put a bead on your oil pan sides and arc seals as well. Like using a tapered- ring ring compressor, once you discover TRS in the 6' caulking gun tube, you'll wonder how you got along with anything else.

 
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