Rear Main Seal Replacement... Now what?

JR Williams

JR Williams

Member
Aug 28, 2019
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Hope everybody is having the best Labor Day. It's a little wet down here in FLA!

So, I'm taking my 95k mile 455 out of my Birchaven for a very leaky rear main seal replacement. Not planning on rebuilding but would like to replace
everything I can while it's out. Here's where I could use some much needed advise.

What would you replace while it's on the stand? Bigger oil pump? Paint it lime green with flowers? Do you have a specific part that is a "Must Have?"
What brands? Full gasket kit? I'm not the sharpest tool but I am one! :)

I did a compression test and here's the results...
1. 170, 2. 155, 3. 165, 4. 175, 5. 175, 6. 170, 7. 165, 8. 160 (seemed strange that 2 was not above 160, don't ya think?)

Looking forward to your input.

JR
--
JR Williams
St Petersburg FL
77 Birchaven
 
If its gonna be out....i would regasket the whole thing. Pull the heads, manifold etc down to the short block just to have a peak-a-boo at the valves
etc but thats only because i can do it myself.

Chances are, if the rear main is worn out the front main is not far behind.....and if you pulling the timing cover you may as well replace the chain
and gears....in order to get the timing cover off/on you might need to remove ????......you see where im going with this right....lol.

I dont think i"d rebuild it unless the cylinder boars show heavy ridging but everyone is different so YMMV.

Or slam a rear main in it....jamb it back in and deal with the rest as it comes up because all that can be done with the motor in the coach....
--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
YES! What timing chain would you recommend? Double roller?
--
JR Williams
St Petersburg FL
77 Birchaven
 
Does a full gasket kit come with everything I would need?
--
JR Williams
St Petersburg FL
77 Birchaven
 
Depends on which kit. Matt would be whom I woudst asketh. I would recommend using a Ford 460 rear main seal in an exotic rubber type ( help Matt!)
instead of the OEM rope style seal. I would probably would pull and inspect everstuff. A good running engine is the best candidate for a soft
rebuild. Rings, mains, inserts, timing chain &gears, oil pump. Get the heads checked & freshened up. Cam and lifters. Always use quality parts.

> Does a full gasket kit come with everything I would need?

--
C. Boyd
76 Crestmont
East Tennessee
 
If your 455 is stock, it has a rope rear seal. If you have the engine out
and on a rotisserie engine stand, turn it pan side up. Put something on the
floor under it, because you are going to get a bunch of coolant from the
block and heads that didn't drain out when you took the hoses off. Probably
a bunch of oil, too. If you are not going for a complete disassemble of the
engine, clean the outside of the block and pan BEFORE you go any further.
Once your significant other says it is clean, take the pan bolts out, and
remove the pan. If it is your intention to only replace the rear seal, two
ways to go here. Replace it with a two piece neoprene seal from a 460 big
block Ford engine, or use a new rope seal.
Both will require removing the oil pump and rear main cap. Inspect both
ends of the oil pump drive shaft. Any question about its condition, replace
it. There are special tools available to replace the rope seal. They come
with instructions. Read and understand them, and follow them precisely. If
you don't, you are going to be pulling that engine again, real soon. If
your rear main bearing is in good shape, leave it alone, along with the
rest of them.
Replace the front timing cover and timing chain and sprocket set. If
you suspect any bad bearings or cylinder bores, look them over carefully
from the bottom, any scoring, rebuild time. No exceptions.
Jim Hupy
Salem, Oregon

On Mon, Sep 2, 2019, 12:36 PM jronguitar--- via Gmclist <

> Does a full gasket kit come with everything I would need?
> --
> JR Williams
> St Petersburg FL
> 77 Birchaven
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Don't SLAM ANY NEW PARTS into it. Just my opinion.
Jim Hupy

> If your 455 is stock, it has a rope rear seal. If you have the engine out
> and on a rotisserie engine stand, turn it pan side up. Put something on the
> floor under it, because you are going to get a bunch of coolant from the
> block and heads that didn't drain out when you took the hoses off. Probably
> a bunch of oil, too. If you are not going for a complete disassemble of the
> engine, clean the outside of the block and pan BEFORE you go any further.
> Once your significant other says it is clean, take the pan bolts out, and
> remove the pan. If it is your intention to only replace the rear seal, two
> ways to go here. Replace it with a two piece neoprene seal from a 460 big
> block Ford engine, or use a new rope seal.
> Both will require removing the oil pump and rear main cap. Inspect both
> ends of the oil pump drive shaft. Any question about its condition, replace
> it. There are special tools available to replace the rope seal. They come
> with instructions. Read and understand them, and follow them precisely. If
> you don't, you are going to be pulling that engine again, real soon. If
> your rear main bearing is in good shape, leave it alone, along with the
> rest of them.
> Replace the front timing cover and timing chain and sprocket set. If
> you suspect any bad bearings or cylinder bores, look them over carefully
> from the bottom, any scoring, rebuild time. No exceptions.
> Jim Hupy
> Salem, Oregon
>
> On Mon, Sep 2, 2019, 12:36 PM jronguitar--- via Gmclist <

>
>> Does a full gasket kit come with everything I would need?
>> --
>> JR Williams
>> St Petersburg FL
>> 77 Birchaven
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
 
> Don't SLAM ANY NEW PARTS into it. Just my opinion.
> Jim Hupy
>

>
> > If your 455 is stock, it has a rope rear seal. If you have the engine out
> > and on a rotisserie engine stand, turn it pan side up. Put something on the
> > floor under it, because you are going to get a bunch of coolant from the
> > block and heads that didn't drain out when you took the hoses off. Probably
> > a bunch of oil, too. If you are not going for a complete disassemble of the
> > engine, clean the outside of the block and pan BEFORE you go any further.
> > Once your significant other says it is clean, take the pan bolts out, and
> > remove the pan. If it is your intention to only replace the rear seal, two
> > ways to go here. Replace it with a two piece neoprene seal from a 460 big
> > block Ford engine, or use a new rope seal.
> > Both will require removing the oil pump and rear main cap. Inspect both
> > ends of the oil pump drive shaft. Any question about its condition, replace
> > it. There are special tools available to replace the rope seal. They come
> > with instructions. Read and understand them, and follow them precisely. If
> > you don't, you are going to be pulling that engine again, real soon. If
> > your rear main bearing is in good shape, leave it alone, along with the
> > rest of them.
> > Replace the front timing cover and timing chain and sprocket set. If
> > you suspect any bad bearings or cylinder bores, look them over carefully
> > from the bottom, any scoring, rebuild time. No exceptions.
> > Jim Hupy
> > Salem, Oregon
> >

> >
> >> Does a full gasket kit come with everything I would need?
> >> --
> >> JR Williams
> >> St Petersburg FL
> >> 77 Birchaven
> >>
> >> _______________________________________________
> >> GMCnet mailing list
> >> Unsubscribe or Change List Options:
> >> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >>
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

Hahaha....but Jim is correct....im in a unique spot with being able to do it all myself...... i would do it all when its out...its just much simpler
and makes it so much easier.

--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
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