Effective rear main oil seal in a '57 283?

[G B.]

Okay... I admit it. I've never been able to stop '57 Chevy engine blocks from leaking oil at the rear main oil seal. Go ahead and laugh if you want. But, if you can help me, I'll take all the verbal abuse that may go with your advice.

The stock rope seals work for months, but never more than a year or two. Recently I've been installing the two-piece neoprene seal that's supposed to be a direct replacement for the rope. However, the last three of those (installed on different blocks) have leaked from the get-go. I just lived with it.

I'm now faced with another leaking rear seal in a "548" block that was just rebuilt by a local machine shop. They used a Fel-Pro one-piece oil pan gasket and a Best #3711X neoprene rear main oil seal. Sure enough, I've got a 4" diameter oil spot on the floor that forms beneath the clutch inspection cover after I return from a 20 mile drive. If I could tell the shop what to do differently, I would, but every friggin' '57 283 I've owned over the last 50 years has eventually been a "weeper" at the rear.

Here's some 2014 advice from a 55 - 57 Chevy website that I'll try unless dissuaded here. "When I install the 2 piece gaskets I rotate the parting lines slightly so they do not line up with the parting line of the block and cap. Then I clean the tips where the seal halves meet with brake cleaner then superglue the halves together around the crank and use Permatex sealer on the metal to metal machined surfaces of the cap and then install the cap and torque."

If any of you has a running '57 283 block that has not leaked oil at the rear main seal during the last few years, I'd sure appreciate hearing how you achieved that.

Thanks for any help you can give me. Really.

Ah, the heck with it. I'll just install one of those huge plastic diapers like they put underneath new cars.

Jerry

[Edward M.]

Re: Effective rear main oil seal in a '57 283?

Jerry;

Some thoughts on this topic from others on the forum....

Also be sure to check the trifive.com forum

Link:
https://www.corvetteforum.com/forums...main-seal.html

Link to Paragon seal:
https://www.paragoncorvette.com/p-35...-seal-kit.aspx

Post1:
'57 and early '58 283's used the rope. In mid '58 it changed to rubber 2 piece. I don't know if they interchange, but a GOOD (read OLD) parts man will be able to find out. The older catalogs should show if the early and late model '58 seals will interchange.

Post2:
No, the later 2-piece rear main seal doesn't interchange with the early "rope" seal; however, Paragon sells an updated elastomer replacement for the "rope" seal that works great (their #4340K, $25.00). I put one in my '57 when I restored it five years ago, and not a drop after 4,000 miles since.

Post3:
YES!!!!!!!!!!!!!!!!!! There is a Santa Clause and a GOD!!!!!!!!!!!
And there is also a replacement FOUR (4) piece seal conversion for the early small blocks which originally used a rope seal.
I have bought them from the Late Great Chevy folks. Their part number is 26-51. And their phone number is 800-683-1961.
The "kit" consists of 2 seal halves and 2 pieces of HEAVY wire to back up the seal halves. IT IS CRITICAL THAT ALL PIECES BE CORRECTLY INSTALLED! As you probably know, when installing a 2 piece rubber seal, it is recommended to install the halves offset about a 1/4in or so from the block/cap mating surfaces. With this seal conversion for the early V-8s, I also install them offset and then I install the backup wire offset on the OTHER side. This way the joints of the seal and wire halves are not together.

THIS SEAL CONVERSION IS THE GREATEST THING TO COME ALONG SINCE SLICED BREAD! IT WORKS GREATTTTTTTTTTTT!!!!!!!!!!

Post4:
DZAUTO- Is it remotely possible to install this while the engine is in the car?

John Z- I checked the Paragon catolog and could not find the listing you posted.
Thanks,

Post5:
YES! You can install it in the car. The 62-earlier Vettes have gobs of room to remove the pan, without ANY hassle, which is the first prerequisite (WHY, WHY, WHY DIDN'T CHEVROLET CONTINUE TO MAKE IT THIS EASY TO DROP A PAN??????). Then, of course, you need to drop the oil pump and rear main cap. I find it helpful to also loosen the other main caps and allow the crank to drop a fraction. IT IS CRITICAL TO BE SURE THAT ALLLLLLLLLLLLL OF THE OLD, UPPER HALF OF THE ROPE SEAL BE REMOVED BETWEEN THE BLOCK AND CRANK! The pkg for the seal conversion will contain instructions. It is a rather straight forward installation. When you re-install the pan, be sure ALLLLLLLLLLLLLLLL gasket surfaces are cleaned and thoroughly degreased, and be sure to thoroughly seal the front/rear pan gaskets. I like to use either the hi-temp black or Ultra copper RTV on the end rubber gaskets. The excess which squeezes out can be easily wiped off. Or, wait until it sets up and trim it with a sharp blade (razor). TAKE YOUR TIME. TAKE YOUR TIME, or,---------------------- DON'T GET IN A HURRY.

Post6:
Y2K -

You'll find it on page 15, in the Engine Gasket Section - 1955-58, #4340K, "Seal Kit, Rear Main, Neoprene w/wire supports, superior replacement for old style "rope" seal. Includes instructions. 4 pcs."

This is the same seal DZ describes above - same one I used.

[G B.]

Re: Effective rear main oil seal in a '57 283?

Thanks for responding, Ed.

Paragon no longer sells the 4-piece wire-support type seals they offered in 2001. They now sell the 2-piece design that is currently leaking on my engine, the Best 3711X. I've been unable to find a brand name for the 4-piece seal that used to be sold by the Chevy Club, Eckler's, Paragon, etc., but I'm still looking.

What would inspire me to try again is hearing an NCRS member posting under his real name say that right now, at the end of 2019, they have a running '57 Chevy 283 engine in their possession that has not leaked at the rear seal since they rebuilt it 5 - 10 years ago. Short of that, I'm going to remain skeptical that it can be done for any length of time.

Jerry

[Don H.]

Re: Effective rear main oil seal in a '57 283?

I'm in your camp Jerry, though not experienced with 283s. My thing has been 327s.
Like I wrote in this recent thread https://www.forums.ncrs.org/showthre...688#post861688 on the 40083 fuel pump, if there is no drip pan under it, it ain't a shevrolay.

[G B.]

Re: Effective rear main oil seal in a '57 283?

Don, I try real hard to keep an open mind... but it's hard. Because I can't do it doesn't always mean it can't be done by anyone.

I've read many posts (all by people using fake names in unspecified locations) that say "It's easy" and "My engine doesn't leak a drop". Maybe so, but maybe not. When an NCRS member claims something under their real name, however, I tend to believe them.

[Ian G.]

Re: Effective rear main oil seal in a '57 283?

Is the rear seal leaking problem mostly specific to the 57 "548" 283's designed for the rope seal or really any 283?

[Joe L.]

Re: Effective rear main oil seal in a '57 283?

Keep this in mind: Chevrolet did not go to the 1 piece rear seal in 1986 because the earlier rope seal or 2 piece seal worked just as well.

[Perry M.]

Re: Effective rear main oil seal in a '57 283?

OK, my name is Perry Mitchell and I live on Whidbey Island. I am a real person and have been an NCRS member since January, 1977. My membership number is 1239. Now to the question at hand. About a year ago I replaced the rope seal in my original 57 FI Nomad with the replacement two piece rubber seal that you mentioned. It did not have the two wires that the earlier seal kits had. I installed the seal while the engine was still in the car. The hardest part of the project was removing all of the original cork pan gasket. The seal, along with the one piece pan gasket that Joe L. recommended has not leaked a single drop of oil, a complete success. The one big mistake that some have made is putting the seal in backwards. Follow the advice of those that have done this on the Tri-Five forums and you shouldn't have any problems.

[G B.]

Re: Effective rear main oil seal in a '57 283?

Thanks so much for your response, Perry. I believe you.

Did you loosen all the maincap bolts before removing the upper part of the old seal?

Did you offset the new seal ends so one end was recessed in the block and one was in the cap?

Did you use any kind of lubricant or sealant anywhere?

Was the seal kit the Best 3711X?

Jerry

[G B.]

Re: Effective rear main oil seal in a '57 283?

Is the rear seal leaking problem mostly specific to the 57 "548" 283's designed for the rope seal or really any 283?

That's the only seal problem I'm asking about, but the factory-type neoprene two-piece seals I've had in other 283's and 327's have also leaked after a few months on the road.

[Perry M.]

Re: Effective rear main oil seal in a '57 283?

Jerry, I performed this repair a little over a year ago and no leaks since. The seal I used was the Best 3711X. The only cap I removed was the rear main after removing the oil pump. I followed the others recommendation of offsetting the seals ends and put a small amount of sealant on them prior to replacing the main cap. I was a little concerned with removing the rope seal but with the use of a wooden dowel and needle nose pliers, I got it out. Oil the new seal prior to rotating it around the crank. Again, be sure the seal lips are pointed to the front of the engine.

[G B.]

Re: Effective rear main oil seal in a '57 283?

Jerry, I performed this repair a little over a year ago and no leaks since. The seal I used was the Best 3711X. The only cap I removed was the rear main after removing the oil pump. I followed the others recommendation of offsetting the seals ends and put a small amount of sealant on them prior to replacing the main cap. I was a little concerned with removing the rope seal but with the use of a wooden dowel and needle nose pliers, I got it out. Oil the new seal prior to rotating it around the crank. Again, be sure the seal lips are pointed to the front of the engine.

Today I talked to the machine shop that built this long block for me. This is about the eighth or ninth Chevy engine they've rebuilt for me.

They said a couple of interesting things. The block/caps had been aligned-bored in the past. That would make the seal seat slightly egg-shaped. The Best Seal Kit contained no instructions at all. They had installed them before, including several for me, but have never used any sealant on them. The man who assembled my engine recalled that there was a good "crush" on the seal. In other words, neither half was recessed below the cap or block deck.

Paragon Reproductions sells a two-piece seal kit that I think is the Best 3711X. They offer some installation instructions on-line. Their instructions don't mention off-setting the seal ends, but do ask that the seal be lubricated and the seal seat "sidewall" have a coat of Permatex Ultra Copper (101B). That's not going to be possible for the seal seat half in the block since the crank is in the way, but I'll sure put some Permatex on the cap half.

Tomorrow I'll drain the oil, then remove the exhaust cross-over pipe, starter, oil filter, clutch inspection covers, oil pan, oil pump, and rear maincap. I'll bring the engine assembler over to inspect everything before proceeding further. I'm going to give this my best shot, but I think complete success is unlikely.

Thanks for your advice, Perry. I do appreciate hearing it.

[Mike M.]

Re: Effective rear main oil seal in a '57 283?

jerry:i've got 3 57 FI 283's and they all are leak free. I've used the 4 piece rear main seals for years( 2 neoprene along with the 2 metal wires). I got the seals years ago from gary Pronesti(got only know where gary got them). I've got a spare set I never used I'll send u if u can use it. on the cuff. regards, mike

[David G.]

Re: Effective rear main oil seal in a '57 283?

jerry:i've got 3 57 FI 283's and they all are leak free. I've used the 4 piece rear main seals for years( 2 neoprene along with the 2 metal wires). I got the seals years ago from gary Pronesti(got only know where gary got them). I've got a spare set I never used I'll send u if u can use it. on the cuff. regards, mike

I have had the same experience. I built a 265 engine for a 55 Corvette and installed the rope seal as I had done before and it leaked
like crazy. I installed one of the Pronesti seals and NOT A DROP leaked. No part number on the package though.
Take Mike up on his generous offer.
Happy New year.

[G B.]

Re: Effective rear main oil seal in a '57 283?

jerry:i've got 3 57 FI 283's and they all are leak free. I've used the 4 piece rear main seals for years( 2 neoprene along with the 2 metal wires). I got the seals years ago from gary Pronesti(got only know where gary got them). I've got a spare set I never used I'll send u if u can use it. on the cuff. regards, mike

I really appreciate your offer, Mike. Unless I find a glaring reason for the leak when I take the thing apart today, I'll take you up on it. I'll let you know this evening.

Jerry