Rear Main Seal Install

[dryheat]

My 64 - 383 engine is due back from the machine shop any day now so the assemble process is about to begin.

I remember years ago struggling (on a different 383 motor) with getting the rear main to seal correctly and was hoping to get some advise / instructions on the proper technique(s) for installation. Pictures would be appreciated too!!!

Thanks ...

 

[MoparMitch]

Rope seal or replacement neoprene ?

 

[dryheat]

Neoprene from a Felpro kit ... I think that is fairly easy to install as I recall ... it's those two strips on the side of the bearing cap that really irritated me.

 

[racedodge]

dont use those strips, just use silicone instead; you will be much more happy that way. Make sure you put a generous amount of silicone in the upper groove and ensure your neoprene seal's lip is facing the correct direction (see instructions on main seal kit). Do the same for the lower seal and apply a bead of silicone in between the cap and block but not so that it will dry near the lip of the seal itself.

if this is confusing, let me know, not sure I explain stuff well sometimes.

 

[Moparmatt72]

I bought the billet one from mancinni racing, its a good piece, and I stagger the rubber seal so the ends aren't right at the ends, but dip into the slot on the cap and block. On the billet one it has 2 seals on the side that lock down so they don't move when installing them.

 

[Mopars & Missiles]

I bought the billet one from mancinni racing, its a good piece, and I stagger the rubber seal so the ends aren't right at the ends, but dip into the slot on the cap and block. On the billet one it has 2 seals on the side that lock down so they don't move when installing them.

:iamwithstupid:

Yep, the newer billet style rear main seal kit is far superior to the original factory type. Does away with the fiber strips on the sides that are supposed to swell up to seal.

 

[69Bee]

Personally, I liked the seals with the side pieces. I guess you have to be an old fart to know how to install them properly. You soak them in mineral spirits, and push them in. After they swell, they will NOT leak. The Fel-Pro alternative is to gush silicone between the sides, and install a wet pipecleaner, how lame and MESSY.

 

[Mopars & Missiles]

I guess you have to be an old fart to know how to install them properly.

:argue:
Well, thanks for insulting another old fart. In fact, I've probably got a few years on you. I've been working on these cars/engines for over 40 years now and I still believe the newer style is better than the older ones. You can soakem' and swellem' all you want and any way you want to. They will still leak eventually, and by the time you finally get the old style rear seal installed, I'll have my engine all buttoned up and ready to run on the dyno. Technology does make some big improvements over time, and just in case you haven't noticed, it has been about 50 years since the original rear seal was designed. No pipecleaners and silicone involved with the seal we were talking about.

Do you still run points and reset the dwell every month too? How about your AM radio? Aren't you starting to run out of stations to listen to on that old contraption? Did you know they have something called "Satellite Radio" nowadays?

I guess we'll just have to agree to disagree on this issue.:argue:

 

[Garys1969RR]

On my 451 and a 383, we put the side strips in without soaking them. (one time we soaked them they swelled up so big there is no way they go in there) Ha Ha. They are tricky to get in with out soaking them. But after installing the seal, I put a nice bead of silicone on the OUTSIDE of the rear seal cap that goes on with the 2 bolts, where it meets the block. So any oil that leaks past the strips, will also have to get past the max oil resistant silicone I used on it. The hot engine oil is supposed to make the side strips swell I believe. Good luck!

 

[5.7 hemi]

Does anyone have pics on what is being talked about? My dads engine is going together and this would help me "visualize" the offset and different style of seals that can be used. Thanks in advance.

 

[69Bee]

:argue:
Well, thanks for insulting another old fart. In fact, I've probably got a few years on you. I've been working on these cars/engines for over 40 years now and I still believe the newer style is better than the older ones. You can soakem' and swellem' all you want and any way you want to. They will still leak eventually, and by the time you finally get the old style rear seal installed, I'll have my engine all buttoned up and ready to run on the dyno. Technology does make some big improvements over time, and just in case you haven't noticed, it has been about 50 years since the original rear seal was designed. No pipecleaners and silicone involved with the seal we were talking about.

Do you still run points and reset the dwell every month too? How about your AM radio? Aren't you starting to run out of stations to listen to on that old contraption? Did you know they have something called "Satellite Radio" nowadays?

I guess we'll just have to agree to disagree on this issue.:argue:

Sorry, didn't mean to offend you, but some old things are better than crap today. I have seen the hi-speed seal you were talking about, I was just commenting on the newer Fel-Pro solution. So, on your list:

1) Ran dual points until I got tired of setting them to get to PT in the morning.

2) I still had the AM radio in ny car, and would have installed the AM/8-track if I had the faceplate for it.

I like living in the past, it's comfy here...:sideways tongue:

 

[dryheat]

Thank you all for you wonderful input and advise ... for the record I'm an old fart, have a points distributor and an AM radio too ... also still have bias ply tires and curb feelers on the car.

Based upon my not so fond memories of replacing the seal at least twice while it was in the other car I think I'll step up and get a mancini replacement and see what happens ... as long as I can keep the wife from finding out.

Thanks again ...

 

[WileE]

Look at this... old farts calling each other old farts... at least an "old fart doesn't smell anymore " ! I refer to myself as a "seasoned citizen" ... I used to hate doing points on the /6

 

[racedodge]

dont use those strips, just use silicone instead; you will be much more happy that way. Make sure you put a generous amount of silicone in the upper groove and ensure your neoprene seal's lip is facing the correct direction (see instructions on main seal kit). Do the same for the lower seal and apply a bead of silicone in between the cap and block but not so that it will dry near the lip of the seal itself.

if this is confusing, let me know, not sure I explain stuff well sometimes.

Well now that we have all the old farts in here identifying themselves.. let me further state that the above post of mine is EXACTLY what I did with my 900 mile 383 I just put in my charger.

absolutely ZERO leaks from the rear main seal. Make sure you have your rear main seal lubricated prior to installing your crankshaft.

 

[Garys1969RR]

Question: Does this refer to putting silicone in the groove where the neoprene seal goes, or in the groove where the side seals go? Or both places.

 

[1moreproject]

I used to only resort to RTV in emergencies but I have to say I’ve been using Permatex Ultra Black more and more lately. It’s not your father’s silicone, much tougher and adheres way better than the original blue stuff from back in the day. (If remembering how poorly the blue stuff worked puts me in the old fart camp then so be it) The side grooves seem like an ideal application for Ultra Black.

 

[Mopars & Missiles]

Sorry, didn't mean to offend you, but some old things are better than crap today. I have seen the hi-speed seal you were talking about, I was just commenting on the newer Fel-Pro solution. So, on your list:

1) Ran dual points until I got tired of setting them to get to PT in the morning.

2) I still had the AM radio in ny car, and would have installed the AM/8-track if I had the faceplate for it.

I like living in the past, it's comfy here...:sideways tongue:

Nah, you didn't REALLY offend me. I was just giving you a hard time for not trying the newer seal.

Yep, LOT'S of old stuff is still better than some of todays "stuff". That's why both of us still have old Mopars. How long you had your Bee? Just wonderin'. I've had mine since '73. Also still have the 8-track player for it that I installed when I was 19, and it still works too! My AM still works as well, but I'm going to convert it to a modern digital AM/FM receiver internally. Externally it will still appear as it did in '69.

Anyway, back at ya' :sideways tongue:

 

[Mopars & Missiles]

Thank you all for you wonderful input and advise ... for the record I'm an old fart, have a points distributor and an AM radio too ... also still have bias ply tires and curb feelers on the car....

Bias ply tires? Still got those too!

Atlas H78-14's (1st pic)

Lee GT300 G70-14's (2nd pic)


Sorry, no curb feelers. But I sure know what they are!

 

[racedodge]

Question: Does this refer to putting silicone in the groove where the neoprene seal goes, or in the groove where the side seals go? Or both places.

where the neoprene seal goes and the side seals is correct. and, to verify... i use permatex RTV ultra black silicone.

 

[Malicious]

I've got a 440 on an engine stand at the moment, supposed recent rebuild. I'm going to swap the sump over anyway, should I update the rear main seal to a billet setup? I can do it without pulling the crank yeah?

I got told to avoid changing it elsewhere because of how finiky they can be. But I'd really rather not have to pull it soon after installing just to fix a rear seal, so I'm a bit torn between changing it and leaving it.

Thoughts?