Another rear main seal question

[nvrstuk]

The only reason why you would need to use thread sealant on a Bronco in TWO places would be the D44 ring gear bolts up front and the Ford 9" ring gear bolts if the thread sealant held for more than a few years, but thread sealant isn't reliable enough on those applications so you SHOULD wire tie all the ring gear bolts on both the front and rear especially when running lockers like ARB's.

The ring gear bolts backing out on the 9" (& the D44) is much more common than most can believe but very common on ARB applications. Wire tie those bolts. Personally I don't know of anyone who has had their D44 ring gear bolts back out but mine have... I used my ARB a lot in my D44 since I installed it in Feb of '87 - but since replaced with a D60 with or course, another ARB. Same with the 9", had the ring gear bolts back out on it also but it took years.

You follow everyone's instructions above and you're good. I've done my fair share of rope seals on early SBC's and SBF's... more than I care to remember. Clean, clean, clean with alcohol, not Brakleen. When your alcohol soaked towel is clean after wiping then it's clean enough to apply RTV to seal everything up tight.

Good luck

 

[Broncobowsher]

That reminds me, I just saw a conversion seal. 1-piece rear main that fits a 2-piece seal block. I was going to look into it more but it looks like I forgot to bookmark it. And now I can't find it. But I am finding you can machine an old block to take a 1-piece seal.

 

[jamesroney]

That reminds me, I just saw a conversion seal. 1-piece rear main that fits a 2-piece seal block. I was going to look into it more but it looks like I forgot to bookmark it. And now I can't find it. But I am finding you can machine an old block to take a 1-piece seal.

Please post a link if you can find it. I just machined a 5 bolt 260 block for a 1 piece rear main from a 5.0. Also had to machine off the slinger / flange off the crank, and polish the rope seal knurl. Would have really liked to have known of a retrofit solution.

 

[ba123]

I appreciate the detailed post, thank you sir.

I'm going to try and drive it out with a punch, lacking a better ideas.

Also, I have no reason to pull and clean the bolts, so I'll make sure they have a little oil and in they go.

Sorry, late to this party…what about a slide hammer. That would prob be the easiest.

 

[jerry]

Again, sincerely appreciate everybody's input.

Got the seal from the cap out. Whoever installed it sealed all the way around it.. But they did remove the pin. So I was able to remove that by driving it out using a straight pick, and now it's the tedious cleaning to get it as clean as I can.


I have been cleaning it with brake clean.... I'm about to go grab the isopropyl and do some more. Thank you for that tip.

 

[jerry]

Here's a photo of the stamping on the rear bearing. Interpretation appreciated, I have zero experience rebuilding an engine or interpreting this.

 

[ba123]

Again, sincerely appreciate everybody's input.

Got the seal from the cap out. Whoever installed it sealed all the way around it.. But they did remove the pin. So I was able to remove that by driving it out using a straight pick, and now it's the tedious cleaning to get it as clean as I can.


I have been cleaning it with brake clean.... I'm about to go grab the isopropyl and do some more. Thank you for that tip.

I have had really good luck with spray adhesive remover...this one:
https://www.amazon.com/gp/product/B000BQYA7W/?tag=classicbroncos-20

 

[jamesroney]

Here's a photo of the stamping on the rear bearing. Interpretation appreciated, I have zero experience rebuilding an engine or interpreting this.

It's a King Bearing, part number = M529L, construction = AM, Size = .020 under.

The M529L is listed on the BOM along with the F529 (#3 thrust bearing) for the main bearing set MB529SI. (L) is for Lower. (U) is for Upper.
AM Corresponds to King Bearing construction K-783, which is an aluminum bearing conforming to SAE 783. It is a low to medium performance engine bearing. Should be about the same as a Clevite P-series.

All you care about is that it is .020 under, which means the crankshaft has been turned at least once, and was bad enough that it needed to go .020. So if you ever rebuild that engine, just make a mental note that you will need probably need a crank. In the old days, .030 was the most you would ever cut...but there are bearing makers out there doing -0.050 nowadays.

I usually stamp the undersize crank info on the rebuild tag so that the next guy knows where I left it. No one has ever called me and said "thanks."

 

[jerry]

Status update:
Got the cap cleaned up, and a dab of black RTV in the pinhole. Decided I'd put it off long enough and got under again.

For the life of me, I can't get the top part of that seal to budge. My current weapon of choice is a nail set in a 10 mm socket, on a long extension so I can have clearance to hit it with a hammer. No dice.

Suggestions are appreciated. Frustrated but not giving up yet. . However, in the back of my mind, I'm also wondering if the best option at this point (given that I can't really pull the engine) is to to clean it up, put RTV on the ends, and hope for the best.

While I do not see evidence of it, I can't rule out that the previous mechanic may have used anaerobic gasket maker on the upper seal. He definitely did on the bottom.

Anyway, going to take a break until I hear from y'all. Thanks again, can't say enough how much I appreciate the advice.

 

[jerry]

Sorry, late to this party…what about a slide hammer. That would prob be the easiest.

I do have a slide hammer. What are you thinking - drill into the existing steel core of the rubber seal, insert screw, and hopefully yank it out?

 

[Wild horse 75]

Automatic or manual trans? You may have to disconnect the torque convertor or release the clutch to let the crank fall the little bit it needed. I’ve just used a pin punch to get the old one out. Then once you get it like 1/2” out use some needle nose pliers to pull it around while you rotate the crank. Don’t pull straight down though. Need to rotate it out with the crank.

 

[jerry]

Automatic or manual trans? You may have to disconnect the torque convertor or release the clutch to let the crank fall the little bit it needed. I’ve just used a pin punch to get the old one out. Then once you get it like 1/2” out use some needle nose pliers to pull it around while you rotate the crank. Don’t pull straight down though. Need to rotate it out with the crank.

Manual trans, should have stated that off the bat (and also a good thing to put in my signature, will do so now).

 

[Broncobowsher]

Loosen ALL the main bearing caps. Let the crank drop down a little bit. Don't actually remove the caps, Just a little loose at the front and a little looser at each cap toward the back. Give yourself some room to work.

The transmission will probably be holding the back up more than anything else. But there is tolerance in the parts, so room for it to gain a tiny bit of clearance.

 

[jerry]

Loosen ALL the main bearing caps. Let the crank drop down a little bit. Don't actually remove the caps, Just a little loose at the front and a little looser at each cap toward the back. Give yourself some room to work.

The transmission will probably be holding the back up more than anything else. But there is tolerance in the parts, so room for it to gain a tiny bit of clearance.

Not sure how much I loosened the very front, will double check.
And, I have yet to loosen the alt and power steering belts... My logic being that they would exert leverage and force the tail end of the crankshaft down.

 

[Broncobowsher]

Belts should be fine as is. If anything they will be levering a little in your favor. All you are trying to do is drop the back.

Realized the last one I did was on a stand. Didn't pull the heads, was just resealing the engine. Didn't have the transmission to deal with, nor did I have the timing cover (was putting on a fresh chain). Amazing how much work was needed on a 60k stock engine. Today 60k still have the factory plugs in it.

 

[jamesroney]

Loosen ALL the main bearing caps. Let the crank drop down a little bit. Don't actually remove the caps, Just a little loose at the front and a little looser at each cap toward the back. Give yourself some room to work.

The transmission will probably be holding the back up more than anything else. But there is tolerance in the parts, so room for it to gain a tiny bit of clearance.

#3 main thrust bearing will prevent the crank from tilting. Transmission input shaft will prevent the rear from falling. Timing chain will hold up the front along with then timing cover seal, and of course the v-belts.

You are at a real crossroads. There is every reason to believe that the same idiot that glued your lower seal to the main cap also glued your upper seal to the block. It will NEVER allow itself to be rotated in the block. You will need to “peel” it out of the block. That means you need to drive a shim around the circumference. Which means you need at least 1/8 to 1/4 inch of clearance between the crank and block.

That means you have to split the bell. Either the trans goes rearward, or the engine goes frontwards. I’d hang it on a hoist, and move the engine…just in case it needs to come out. I’d also remove the #3 main bearing, not just the cap, but the upper insert as well. It’s a pain to roll that upper bearing, so do it while the other mains are tight. You are trying to drop the whole back of the crank 1/4 inch.

Given all that, I’d give serious thought to putting it back together until you are ready to try it. Once you try to peel that upper seal, you are committed.

 

[PDQ]

See post #2 in this thread........I am so pulling for you to win this......but if it ends up like my deal and you want a good source for a 347ci....just let me know. But that was never my plan!

 

[bmc69]

That reminds me, I just saw a conversion seal. 1-piece rear main that fits a 2-piece seal block. I was going to look into it more but it looks like I forgot to bookmark it. And now I can't find it. But I am finding you can machine an old block to take a 1-piece seal.

Tim Meyer recently introduced a one-piece rear main seal for all Cleveland engines and the 351W. Otherwise, many a 289/302 and 351W block has been machined to accept/use the late-model 1-piece rear main seal.
https://www.tmeyerinc.com/product/1-piece-rear-main-seal-2/

 

[Broncobowsher]

Tim Meyer recently introduced a one-piece rear main seal for all Cleveland engines and the 351W. Otherwise, many a 289/302 and 351W block has been machined to accept/use the late-model 1-piece rear main seal.
https://www.tmeyerinc.com/product/1-piece-rear-main-seal-2/

That's the one. And probably why I couldn't find it. Maybe they will have the 289/302 seal out by the time I get around to building one up. Or try and find a machine shop that will do the block mod.

 

[jerry]

So... I want to thank everybody for their input and support.
I decided to "punt". Replaced the bottom half of the seal, a little RTV on the ends, and some anaerobic sealant where the factory manual said to put it.

Buttoned it up last night, will add oil Friday. I also need to remounted dipstick tube. It finally dawned on me that leaving on the inner fender, the way the previous owner had it, is not the right way to do it. So I'm going to mount either to a stud or clamp to a header.