FYI FORD - MustangSteve's Ford Mustang Forum
The Internet's Most Knowledgeable Classic Mustang Information
IF YOU HAVE A QUESTION ABOUT CLASSIC FORD MUSTANGS, YOU HAVE COME TO THE RIGHT PLACE!
MustangSteve has over 30 years of Mustang experience, having owned 30 of them and restored several others. With the help of other Mustangers, this site is dedicated to helping anyone wanting to restore or modify their Mustang.... THERE ARE NO DUMB QUESTIONS!!!!!
Visit MustangSteve's web site to view some of my work and find details for:
FYIFORD Contributors' PICTURES - Power Brake Retrofit Kits for 65-66 Stangs - Classic Mustang FAQ's by MustangSteve - How to wire in a Duraspark Ignition - Mustang Ride Height Pictures and Descriptions - Steel Bushings to fit Granada Spindles to Mustang Tie Rods - Visit my EBAY store MustangSteve Performance - How to Install Granada Disc Brakes MustangSteve's Disc Brake Swap Page - FYIFORD Acronyms for guide to all the acronyms used on this page - FYIFORD Important information and upcoming events

You are not logged in. Would you like to login or register?

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  » Rear main seal?

    • 1 of 1

       

    7/02/2024 7:03 PM  #1

    Rudi
    Senior 24-7 FYI Addict

    Offline

    From: Stuck in the 50's Welland Ca
    Registered: 4/01/2013
    Posts: 3,944

    Rear main seal?

    I have developed a small seepage at the rear of the oil pan and from the best I can determine it’s the rear seal. I am using 5w-40 synthetic and have 55 # oil pressure cold, 45 # hot.
    I hate any kind of leak and usually try to correct them toot sweet.
    Now the leak is not all that bad and at this time  there is no way I am replacing it, it’s an 86 5.0  block  and quite sure a one piece seal.
    My question is should I use some Blue Devil seal repair in the oil or just live with it till winter shut down.

    Last edited by Rudi (7/02/2024 8:17 PM)

    Good work ain't cheap, Cheap work ain't good!   Simple Man
     

    7/02/2024 11:54 PM  #2

    Ron68
    Senior 24-7 FYI Addict

    Offline

    From: Mukilteo, Washington
    Registered: 4/01/2013
    Posts: 1,541

    Re: Rear main seal?

    Got a rear main seal leak on a Jeep Grand Cherokee 4.7L that was a long block rebuild. Put in a bottle of Blue Devil. That was seven years and 24K miles ago and no leaks. Sealed up within just a couple of days and been good ever since.

    68 coupe - 351W, 4R70W, 9" 3.25 -- 65 convertible - 289 4v, C4, 8" 3.00
     

    7/03/2024 5:32 AM  #3

    TKOPerformance
    Hyper FYIFORD ADDICT

    Offline

    From: Newark, DE
    Registered: 12/15/2014
    Posts: 7,433

    Re: Rear main seal?

    A buddy of mine has a truck he bought used and it had a RMS leak.  He put some Blue Devil in it and the leak went away.  He was telling me about it when he was over at my house.  When he left I noticed a decent sized oil spot on my driveway.  The next day I told him about it.  It was leaking again.  No idea how long it worked for, but IMO those types of fixes are designed for the guy selling his vehicle.  They generally work for a while, but eventually fail. 

     

    7/03/2024 6:37 AM  #4

    BobE
    Senior 24-7 FYI Addict

    Offline

    From: White Plains, NY
    Registered: 4/04/2013
    Posts: 2,574

    Re: Rear main seal?

    Suggest verifying the leak is not from the valve covers, the intake manifold to china wall area, or a oil pan bolt before changed the rear main seal. 

    65 Fastback, 351W, 5-speed, 4 wheel discs, 9" rear,  R&C Front End.
     

    7/03/2024 7:17 AM  #5

    Toploader
    Senior 24-7 FYI Addict

    Offline

    Registered: 4/15/2013
    Posts: 1,640

    Re: Rear main seal?

    For a few years, I was convinced that I had a rear main seal leak and just lived with it, as much as I hated it.
    I recently changed my sump plug and washer and discovered there was no more leaking.
    I no longer have any drops of oil.

    1964-1/2 D Code Coupe - 289 V8, 4 Speed Toploader, 3.00 ratio rear, Autolite 4100 Carb, 15" tires, Pertronix ignition
     

    7/03/2024 7:58 AM  #6

    Steve69
    Senior 24-7 FYI Addict

    Offline

    From: Madison Wisconsin
    Registered: 4/01/2013
    Posts: 2,727

    Re: Rear main seal?

    Check your oil pan bolts too.  Maybe they have loosened a bit causing the leak.  

     

    7/03/2024 9:23 AM  #7

    Rudi
    Senior 24-7 FYI Addict

    Offline

    From: Stuck in the 50's Welland Ca
    Registered: 4/01/2013
    Posts: 3,944

    Re: Rear main seal?

    Other  than the sump plug I checked all the usual suspects before I posted.
    The engine has about 30,000 miles on it.
    I wonder how the rest of the seals in the engine would react to the Blue Devil elixir?

    Last edited by Rudi (7/03/2024 9:25 AM)

    Good work ain't cheap, Cheap work ain't good!   Simple Man
       •Thread Starter
     

    7/03/2024 9:58 AM  #8

    6sally6
    Hyper FYIFORD ADDICT

    Offline

    From: Surfside Beach,SC
    Registered: 4/02/2013
    Posts: 6,770

    Re: Rear main seal?

    I'm sorta hesitant to use the "mechanic-in-a-can" stuff......I've used it butt.
           Rudi...after all it IS A FORD and like Harleys they like to mark their territory !
           Cat litter is your friend until winter and then........if you haven't accepted the fact...pull the engine...replace the seals...install a radical roller cam (you only live once!)...a set of AFR heads (to take advantage of the superior breathing!)...make plans to drive it to MB to cruise it...come give me a ride....park it in my driveway...and vidit and enjoy life this winter !
    NOW  THERE'S A PLAN !!!
    6sally6

    Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
     

    7/03/2024 10:27 AM  #9

    Rudi
    Senior 24-7 FYI Addict

    Offline

    From: Stuck in the 50's Welland Ca
    Registered: 4/01/2013
    Posts: 3,944

    Re: Rear main seal?

    Sounds like a great idea Mike, if only I was up to the task.

    Good work ain't cheap, Cheap work ain't good!   Simple Man
       •Thread Starter
     

    7/03/2024 10:37 AM  #10

    MS
    Forum Originator

    Offline

    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 12,172

    Re: Rear main seal?

    I used that stuff on my 427 a long time ago.  Seemed to help for a while but eventually put a new seal and crankshaft sleeve in it.

    I highly recommend the FelPro crankshaft repair sleeves, even if there is no apparent damage to the crank.  Never had any seepage after installing a sleeve.  I even put one in my brand new 331 crank for the 65.

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    7/04/2024 8:40 AM  #11

    Rudi
    Senior 24-7 FYI Addict

    Offline

    From: Stuck in the 50's Welland Ca
    Registered: 4/01/2013
    Posts: 3,944

    Re: Rear main seal?

    Other than dropping the transmission can a one piece seal be r&r , oil pan in place?
    How about the Fel Pro sleeve at the same time?

    Good work ain't cheap, Cheap work ain't good!   Simple Man
       •Thread Starter
     

    7/04/2024 2:40 PM  #12

    MS
    Forum Originator

    Offline

    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 12,172

    Re: Rear main seal?

    That is the beauty of the one piece seal. Remove flywheel and block plate. 
    Drive a #6 nail into the seal body. Remove nail and put a 1” long sheet metal screw in the hole. Grab screw with vise-grips. Pry out the old seal.

    The FelPro sleeve requires a special tool, about $30, made of plastic.  If you know a good machinist (!!!), they could probably make one.  I can send you the dimensions.

    Use red loctite on ID of sleeve.

    Lube the new seal and push it into the block, being careful to not shave off any of the OD.  A PVC fitting, 4” pipe plug works great as an install tool.  Or, whip out your lathe again…

    The block plate keeps it from coming out of the bore, along with the tight fit of the external rubber ribs.

    You know the rest of the drill.

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    7/04/2024 7:46 PM  #13

    Rudi
    Senior 24-7 FYI Addict

    Offline

    From: Stuck in the 50's Welland Ca
    Registered: 4/01/2013
    Posts: 3,944

    Re: Rear main seal?

    Thanks for that great write up,I would like the installation tool dimensions please..
    Any way to make that info a sticky?

    Good work ain't cheap, Cheap work ain't good!   Simple Man
       •Thread Starter
     

    7/06/2024 8:33 AM  #14

    Rudi
    Senior 24-7 FYI Addict

    Offline

    From: Stuck in the 50's Welland Ca
    Registered: 4/01/2013
    Posts: 3,944

    Re: Rear main seal?

    Excellent, you da man Stevo!

    Good work ain't cheap, Cheap work ain't good!   Simple Man
       •Thread Starter
     

    7/09/2024 1:14 PM  #15

    MS
    Forum Originator

    Offline

    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 12,172

    Re: Rear main seal?



    This drawing has all the needed dimensions to make the #16300 installation tool for the Fel-Pro 289/302/5.0 crankshaft repair sleeve #16250 or #21-2100

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    7/09/2024 6:39 PM  #16

    Greg B
    Senior 24-7 FYI Addict

    Offline

    Registered: 4/01/2013
    Posts: 1,676

    Re: Rear main seal?

    We need a dedicated spot for popular part numbers for seals and gaskets and such.   Googling anymore seems to bring up answers that are completely for different engines. 

    I know the tool for 351 sleeves is discontinued.    I was trying to find the part numbers for the 351 sleeve and tool and seal.   Just to keep them all in a handy location. 

    I remember Felpro recommended the regular seal line with repair sleeves and not the premium material.

    If multiple things can go wrong, the one that will go wrong will be the one that causes the most damage.
     

    7/10/2024 6:37 AM  #17

    BobE
    Senior 24-7 FYI Addict

    Offline

    From: White Plains, NY
    Registered: 4/04/2013
    Posts: 2,574

    Re: Rear main seal?

    Greg B wrote:

    We need a dedicated spot for popular part numbers for seals and gaskets and such. Googling anymore seems to bring up answers that are completely for different engines.

    I know the tool for 351 sleeves is discontinued. I was trying to find the part numbers for the 351 sleeve and tool and seal. Just to keep them all in a handy location.

    I remember Felpro recommended the regular seal line with repair sleeves and not the premium material.

    I installed a rear main seal & sleeve on my 351W in 2014, still no leaks. To my knowledge the below parts are still available.
    Sleeve: Victor Reinz # A332
    Installation Tool: Fel-Pro #16301

     

    65 Fastback, 351W, 5-speed, 4 wheel discs, 9" rear,  R&C Front End.
     

    7/10/2024 11:06 AM  #18

    6sally6
    Hyper FYIFORD ADDICT

    Offline

    From: Surfside Beach,SC
    Registered: 4/02/2013
    Posts: 6,770

    Re: Rear main seal?

    With Rudi's unlimited talents in machining... why don't we ask him to machine these parts that are no longer available ?!
    He would be compensated for his talents and we would be able to receive custom pieces that may not be available on the open market !
    (I love to "volunteer" other peeps talents !!!)
    6sal6
    This^^^ is my way of forcing Rudi and Lyn to come to Myrtle Beach this winter. He will gladly come just to punch my in the nose for my volunteering antics !! 6s6

    Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
     

     

    1 of 1

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  »  Rear main seal?

    • Board footera


    REMEMBER!!! When posting a question about your Mustang or other Ford on this forum, BE SURE to tell us what it is, what year, engine, etc so we have enough information to go on.