BOP 455 Rear seal Install- Step by Step

I have had a few folks ask for this, and don't mind sharing.

Once again, as I mention in every "how to" I post.. this is how I do it.. and it's been proven by dozens of installs. Someone else may have other ideas, and that's fine, I don't mind..

Step by Step:

1. Insure you have purchased the BOP RMS 02 rear seal.

2. Open the package, and discard the instructions, unless your building a Pontiac.

3. Fit the seal.. I have found the best way to do this is to use an old rear main cap from another engine, or if your careful, you can fit both halves, using the cap that goes to the engine your working on. Our parting line is right in the center of the mains on this engine, so you just use the cap to fit both.- Line one side up so it's flush with your cap, and then grind the other side so it's out about .005 to .010.. or just above the surface. I will confess that I have done this so many times, I just do it by eyeball now.. One side flush, and one side sticking up "just a little bit" is what we are after here. Do this to both halves, grind only one side of each seal.

I use a small right angle variable speed die grinder with a 2" rolock "green corps" 40 grit disc to grind the seal very carefully. Keep the ends square and straight. you can use a bench grinder, disc grinder, file board.. whatever.. Main thing is to keep it straight and square.


Now let's check our fit..

Install the rear seal so the parting line does not line up with flush with the cap.. like this:



Offset the seal half in the block so it will work with the seal as you have it installed in the cap. Now install the cap, and tighten the bolts.

Here is what we see..




What we want to observe is the seal halves coming together, with no bulging.. like this



On this seal, I actually left it a little big, to illustrate what you don't want to see.. look at the bulge here, where the halves come together..



Once you have verified that you have a good dry fit, it's time to install the sealer.

4. Use Permatex "the right stuff" in either the cheese-wiz can, or the calking tube. You want a small tip for this, so don't go hogging to much off the end of the tip. put a very small bead of sealer in the block and cap seal groove. Do not put any sealer in the area where the seal ends will come together.



Now, you can see that someone was here before me, and dimpled the block with a punch.. don't do that! I am fairly sure that the dimple hurts more than it helps.. the seal is not going to spin with the sealer on it.. in fact, you will need a pliers to pull it out someday.

But if it's been dimpled like this one.. no biggy, the sealer will save the day for us.

5. Now take a Q-tip and take most of the sealer you put in, back out.. we are looking for a thin coating, about the thickness of a sheet of paper here. It should look like this:



See-thru

Note my finger at the point where I stopped with the sealer.. this is where my seal halves will come together.





6. Now install the seal, lip pointing toward the inside of the engine. I have built many wet sump vacuum pump race motors, and never turn the seals around, and never had leaks. I limit my vacuum pumps to 11-12". Dry sump motors may be different, consult your pump manufacturer for their recommendation.

7. Now refit the main cap on the engine, and tighten the bolts.. inspect the seal to insure that no sealer is around the lip of the seal, remove any that may have squished up there, but if you followed these directions, there should be nothing.

In final assembly, lube the seal generously, and put a see thru film of the right stuff on the main cap, in the area around the seal.


___________________________


I have used this method on rear seals on 455 Buicks since the 90's, when we used to cut the Caddy seals down. Then TA found the Ford seal that works (no trim) and I bet I installed at least 50 of those No trim TA seals.. never had one leak that I am aware of. I only ever had one rear main leak, that car also leaked with the BOP seal, it had a rare issue with the crank.

Good luck, and happy sealing..

JW

 

:gp:

Wow... thanks Jim. Very good, detailed explanation. Just wish I had this info when I installed my BOP seal. But I guess I must have done it 'good enough' a couple years ago as I don't seem to have any leaks... yet. I am going to print this and save it for next time though. Thanks again!

 

Ya, it's hit or miss without the sealer.

I put in 4 or 5 of them per the instructions, without the sealer.. but had one develop that annoying little drip, so I reverted to previous procedures.

JW

 

I like that use of the Q-tip! That alone would of saved me with the recent rear main fiasco, as it was an excess of Ultra Black that came around the back side of the seal and pushed into the backside of the lip causing it to deform, then leak excessively. I've used essentially the same method on the grinding/cutting of the seal. Just a smidge of an interference fit but nothing dramatic.

 

I realize this is an older thread, but I was wondering if these instructions would be the same using the T/A 1515 neoprene 350 rear main seal? Also T/A lists their seal as a "no trim" seal, so is the fitting step necessary? I am planning to do this in the car as I already have the transmission out of the car. With the flex plate removed it seems I have pretty good access to do the project.
Is it recommended to NOT get any sealer between the ends of the seal pieces where they meet?
Thanks,

 

Yes, I used this method with dozens of TA 350 and 455 seals, with a very low failure rate.

JW

 

Thanks for the quick response! I'll be ordering a seal kit from T/A tomorrow.

Is there any tips for getting the wedge shaped pieces into the groove on both ends of the cap?

 

I got the old seal out of the 350 today. Actually not that old, was installed in June. It was the Ford 460 seal. Discovered it was installed backwards, and the ends were not offset from the cap parting lines. Also the length hadn't been trimmed as detailed above.

Interesting note, the part #s on the 460 seal are exactly the same as on the seal I just got from T/A.

I have a question concerning the RTV sealer. Does Permatex Ultra Copper high temp work the same as the Permatex right stuff black?

 

Any comments about the RTV sealers? I don't want to have to do this project again, want to make sure I do the best possible job I can to try to insure the rear main won't leak.

Thanks,

 

Technically, any form a gasket type product should work.

JW

 

Thanks, and also appreciate the detailed write up on this project.

 

Jim, I have purchased a good running 455 and was thinking about upgrading from the old rope seal while the engine is on the stand. Would it be possible to do a decent job of installing the T/A seal without pulling the crank? The engine seems to be fairly dry as is so wondering if I should try it? Thanks in advance.

 

I would also like to add my appreciated thanks to Mr. Weise for this helpful information. I wanted to fit a 2 piece seal to my re-built Nailhead, but NONE of the manufacturers or suppliers would give me any instructions or help
Because I did not feel confident enough, went with the original rope seal. Hope it doesn't leak. At least I can refer back to this thread in the future if I ever want to retrofit the 2 piece style.

 

When I use a TA rear seal, we re-size the crank seal surface to 3.374, which is the shaft size the seal was designed for. Had very good luck doing that in the past year or so. This grinding also removes the serations for the rope seal from the factory, as well as any rust pits and provides a perfect surface for the seal.

So we do a little work to use that seal..

If it's not leaking, don't fix it, at this point it's not likely to just start.

 

So I was swapping out my tranny oil,filter and pan today and noticed this little drip. I wiped it clean and after a bit it was there again does this mean my rear seal is leaking?? Sorry for the pic being upside down.

 

Could you tell if it was engine oil or transmission fluid. It could be either based on the area. Rear main engine seal or front pump seal on the transmission. There are only 5 bolts (looks like you're missing 1 in the corner) holding that cover on. You can pull it off to inspect where the leak is coming from. Then you'll hopefully have your answer.

 

It looked like engine oil to me it wasn't red at all. Yes I noticed I was missing one of those bolts also. I guess I will pull the cover off next weekend and take a look. My car was oil coated underneath at some point in the last few years I'm hoping maybe some of that oil got up inside and when it heats up it just runs out.

 

So I got around to pulling off the flex plate/flywheel cover to inspect the oil drip. I didn't see it was coming from the rear main seal but more at the back of the pan. I checked the oil pan bolts and some were loose or not as tight as I thought they should be. So I tightened all of them up a bit,wiped everything down and fired her up!! As it was idling in park I couldn't see any oil leaking anywhere and I couldn't road test it due to consuming a few wobbly pops. What I DID notice was the flex plate didn't look like it was spinning right? I'm no rocket scientist but it shouldn't be wobbling as it's spinning right?? I've been trying to load the videos. The torque converter is spinning straight as an arrow which is the weird thing

 

This is a great post
So I guess I’m not the first rebuilding an entire 455 only to have the new rear main seal leak

question: is there any way to install the seal without pulling the engine again

inrecall back in the day there was a type of Chinese handcuff tool that you could install the upper piece Of the rope seal provided you could slide out the old one

If I have to pull the crank I should be able to leave the pistons in the block? No?

Your wisdom is appreciated

 

If you can get the pan far enough off to access the rear main cap, you can install a new rubber seal.