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Rear Main Seal Leak Fixed..I think???

11853 Views 18 Replies 10 Participants Last post by  bigblockfairlane
3
First I would like to thank waycool jr for posting this thread..http://460ford.com/forum/showthread.php?t=135753&referrerid=25042
I recently built a 514 stroker and have a little less than 200 miles on her and I started to develop a rear main leak..I found this thread and decided to pulled my motor since things like this would drive me crazy plus I have WAY to much money in this motor for it to leak any kind of fluid.. I pulled the main caps and slightly pryed the end of the crank up slightly so it would be easier to install and remove the seal..I first inspected the rear main cap bearing..Here is a photo..



As you can see the rear main seal was not letting the bearing seat all the way down on the crank..Next I inspected the old seal which I removed from the block and cap..I noticed that the back half of the seal was starting to separate right down the middle..The rubber was cracked right down the middle..Here is a photo..



I first measured the stick out of the seal with the other end flush in the main cap..The old seal in the cap measured .060 thousand with my digital micrometer..Yup differently a problem.. :( Next I did the same with the seal the was in the block..it measured .080 thousands with the micrometer..A total of .140 thousands..Way Cool Jr stated in his thread that a TOTAL of .020 to.030 was acceptable..I was .110 thousands to MUCH!!!!

I purchased a new FORD Motorsports rear main seal from my for deal for $17.00 bucks including shipping..The old seal was the Felpro $40.00 dollar seal that I purchased through Summit Racing..There was a small part number on both seals..Do you want to guess that it was the same number..Yup it sure was..Save my self $22.00 bucks plus..:)

Well I go and measure the NEW seal in the cap first..It measured .074 thousands!!! WOW.. If I just slapped that new seal in, I be back to square one...I then measured the New Block seal..It measured .105 thousands!!! A total of .179 thousands..The new seal is .149 thousands to much..I used a piston ring filer to get the the desired .020 thousands total..

I have not installed the engine yet but I am hoping that this will cure the dreaded DRIP, DRIP and DRIP leak I had..Once again thanks Wacooljr for posting the the thread on his problem or I might have been pulling my engine a total of six times to finally cure the problem..Here is a picture of my beast..:)

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What brand valve covers are those? I like them and want a pair. Thanks, Frank.
What brand valve covers are those? I like them and want a pair. Thanks, Frank.
Yeah that's what everybody says until they find out the price. They are made by Blue Thunder and will cost a little over $300.00 with shipping..Just F.Y.I. :)
Who makes that accessory drive kit if I might ask?
Who makes that accessory drive kit if I might ask?
Concept One Pulleys..A little over 2K with every thing you see..Not cheap but works well..Like I said I have a LOT of money in this motor..Took 5 years of savings to build it..
Damn.... thanks, too much $$$ I just want brackets and the crank pulley cause its a very clean setup.
we want photos or video of that FFR roadster smoking the tires.:D
Still no leak ALL is good..Info is great on this site!
I think that have been the 351 Windsor small block seal that was put in by mistake. I would say that would give you a heck of a leak!
I think that have been the 351 Windsor small block seal that was put in by mistake. I would say that would give you a heck of a leak!
Nope..460 two piece rear main seal from Ford Racing
tank and oil leak

your coolant tank is it homemade .because i running mine this weekend 532 in a ff that has a rear main leak that i tried every thing eccept a crank and a block.
Nope..460 two piece rear main seal from Ford Racing
I'd say that's what you ordered but not what you got....
I'd say that's what you ordered but not what you got....
I had two seals. The old and the new one..Measured out about the same..Both had the same part number on both and were made by Fel Pro..Unless I am unlucky twice I highly doubt that there was a mix up..
oil leak

This is an interesting thread. I just got back from the PRI show in Orlando FL.
When I got there, I made a b-line to the Ford booth to ask about this very issue.
I've done every trick that I know of, done what Waycool Jr suggested, and still a rear main leak. I met a guy there that is head of Ford BB crate development.
He freely admitted that the rear main is an issue! He almost looked embarrassed as I talked about my problem.
He told me that they had gone so far as to grind the flange off the crank flywheel flange so that they could see better what was going on, and sure enough, he said in one situation they could actually see light coming through when a flashlight was held on the inside.
He also was aware of the seals being made too long, so that they need to be fitted like Waycool has done. He said that the tooling from that seal manufacturer was wrong, and they make seals under various names.
He did say that he has seen this problem regardless of year.
He also said that he would send me some seals that he had better luck with, but we'll see if he comes through, its only been a couple of days.
While I was there, I talked to a company that makes custom seals (I don't have the name right now, I have to dig though my 75 or so business cards!).
They make custom seals for problems like this, and the interesting thing is that they would make it with only one split, and you kind of thread it on the crank. They had an example there if one. I thought that was a good idea.
The price of the tooling was $1500, then the price of the actual seal depends on how many are bought.
Anybody interested in splitting up the cost of the tool? I'd invest the first $100 and just need to get 14 more. At this point, the frustration of that dam leak would be well worth the money!!
I'd like to hear what some of the other "pro builders" on this site do? Guys that build more than one BBF in a year or so. Do they see this issue too?

Sid
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It will be interesting to see what seals he sends you that he has good luck with..Please post them when they arrive..I am sure a lot of us are interested..
leak

I`m sure somebody has thought of this by now but there is a pointed tip that was used to hold the old rope seal from working out i broke mine out and using the 2piece seal with silicone alittle in the groove and on flat area between cap and block no leaks yet... just my 1 1/2 cents [recession/depression price] Bill
just use an old cleveland rope seal you can cut it to the proper length, it will seal, problem solved
This is an interesting thread. I just got back from the PRI show in Orlando FL.
When I got there, I made a b-line to the Ford booth to ask about this very issue.
I've done every trick that I know of, done what Waycool Jr suggested, and still a rear main leak. I met a guy there that is head of Ford BB crate development.
He freely admitted that the rear main is an issue! He almost looked embarrassed as I talked about my problem.
He told me that they had gone so far as to grind the flange off the crank flywheel flange so that they could see better what was going on, and sure enough, he said in one situation they could actually see light coming through when a flashlight was held on the inside.
He also was aware of the seals being made too long, so that they need to be fitted like Waycool has done. He said that the tooling from that seal manufacturer was wrong, and they make seals under various names.
He did say that he has seen this problem regardless of year.
He also said that he would send me some seals that he had better luck with, but we'll see if he comes through, its only been a couple of days.
While I was there, I talked to a company that makes custom seals (I don't have the name right now, I have to dig though my 75 or so business cards!).
They make custom seals for problems like this, and the interesting thing is that they would make it with only one split, and you kind of thread it on the crank. They had an example there if one. I thought that was a good idea.
The price of the tooling was $1500, then the price of the actual seal depends on how many are bought.
Anybody interested in splitting up the cost of the tool? I'd invest the first $100 and just need to get 14 more. At this point, the frustration of that dam leak would be well worth the money!!
I'd like to hear what some of the other "pro builders" on this site do? Guys that build more than one BBF in a year or so. Do they see this issue too?

Sid
If you set the crush height right then there is either something wrong with the block or the crank. There were some aftermarket cranks out there that leaked because the serrations were put in the wrong way. I once saw a stock crank that had the serrations missing about 1/3 of the way around it. Excessive cap cutting could lead to problems too.
seal

Don`t know if I`ve been lucky or???used a bunch of 2 piece seals never had to cut or trim ,just make sure they were staggered ,cocked whatever u call it one side sticking out of block and the other on the main cap same amt.sealer on facing and attach to block no leaks....However have turned seal wrong way that wasn`t good had to pull motor back out wasn`t enough room to drop pan now have removable center brace on my 66 fairlane I can now drop pan if i have to....JUST MY THOUGHT..........Bill
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