308 rear main seal

Chris SmithChris Smith Expert Adviser
edited 11:54PM in HUDSON Posts: 363
Anyone know if a neoprene type rear main seal is avaliable to replace the rope seal on a 54 308 ?

Comments

  • hermherm Expert Adviser
    Posts: 227
    Criss - Dale Cooper advertises them in the WTN. (513) 821 6200. Norm
  • duncanduncan Expert Adviser
    Posts: 743
    use a seal from a 318 cu. inch Dodge v8 fits like a glove. duncal
  • onerare39onerare39 Expert Adviser, Moderator
    Posts: 912
    Hudson308 wrote:
    Anyone know if a neoprene type rear main seal is avaliable to replace the rope seal on a 54 308 ?

    I think I read here that Dale Cooper has some now... maybe someone else can confirm that.

    Oops... missed it by.... THAT MUCH! :P

    I can confirm that... I just received one from him last month.

    John
  • duncanduncan Expert Adviser
    Posts: 743
    I am sorry I should have said use a neoprene rear main seal from a 318 Dodge v8 engine.Fits like a glove duncan
  • 51hornetA51hornetA Senior Contributor
    Posts: 2,296
    Ditto on Dale's seals I got some from him as well and they are perfect fit you do not have to trim anything.
    www.hudsonmotorcar.org
  • KdancyKdancy Senior Contributor
    Posts: 2,103
    Duncan,
    What years 318?
    53 Super Wasp Coupe ready for restoration
    53 Studebaker Coupe Custom
    64 Champ pickup
    Wellborn, Fl
  • russmaasrussmaas Senior Contributor
    Posts: 558
    Basically Dale trims these down as do we. When you buy over the counter , just cut the ears off and trim with a bench grinder and make sure it sits about 1/16th above the cap and block.
  • Ken U-TxKen U-Tx Senior Contributor
    Posts: 3,223
    Aha, there was not mention of these needing to protrude 1/16Th of an inch beyond the cap and block mating surfaces......the ones I put on Kevin's car were flush or slightly below......It didn't leak when we first started up the car and ran it for awhile, but when he drove it 60 miles round trip to the Hudson meet today, it was pissing oil again when he got home. I suppose the grooves for the seal may be deeper in the cap and block on this car than what the Maas' have dealt with. Anyway, I am now in the quandary of having to redo this job on my own time and having to buy another seal. Not a happy camper right now. I also installed this seal kit in another 7X 308, and I think this one had a bit more of the seal ends protruding past the block and cap mating surfaces. I hope it is not going to leak. I may have to go back to using a rope seal on Kevin's car. Perhaps when these were modified , and ground on the bench grinder (I bought them ready to go, already trimmed) too much was ground off for this particular motor? Maybe I will be better off buying a Mopar 318 seal locally and trimming, grinding it to fit for the 1/16" protrusion?
  • Ol racerOl racer Senior Contributor
    edited January 2016 Posts: 2,263
    FYI
    Ive installed a few Mopar 318 neopreme rear seals now by trimming the tabs slightly then put a dab of the more expensive Permatex Black RTV in each corners with no problem.
  • Ken U-TxKen U-Tx Senior Contributor
    Posts: 3,223
    Hmmm, I now see that the 1993-1999 318's used a seal without the "ears" or wings.......would these be a btter choice than having to cut the "wings"  off the earlier style 318 rear main seals?
  • RL ChiltonRL Chilton Administrator, Moderator
    Posts: 5,039
    Surely so, Ken.  Especially if yo don't have to do any grinding, which can give you a variable height difference. 
    Russell http://www.52hornetvert.blogspot.com HETrlchilton52@gmail.com (drop the HET)
  • Ol racerOl racer Senior Contributor
    edited January 2016 Posts: 2,263
    FYI

    Be sure to research the later model crank Diameter... For some reason I recall something mentioned on the old Forum about using newer 318 seal, but I could be wrong...

    Also, somewhere I read of rotating Neoprene Deal slightly so not have gap in the corners

    (Maybe I shouldnt read so much)
  • Oldfarmer1947gmailcomOldfarmer1947gmailcom Expert Adviser
    Posts: 1,314
    The crank on a 318 is several .000 under sized from a big block crank.
  • Ken U-TxKen U-Tx Senior Contributor
    Posts: 3,223
    Yes, Ken C is right, the 360 uses a 2.810" main journal whereas the 318, 273 used 2.500" like Hudson.
  • Ken U-TxKen U-Tx Senior Contributor
    Posts: 3,223
    I ordered one of the old wing type seal set, and one of the newer "wingless" seal set. Will carefully measure and compare.
  • Ken U-TxKen U-Tx Senior Contributor
    edited January 2016 Posts: 3,223
    Same seals are used on the Chrysler 3.9 liter V6. The change to the wingless version was 1992. The purpose of the "wings" was to seal the gap between the rear main bearing cap and the block at the mating surfaces, as these earlier engines had a horizontal groove for the rubber wings to set in with a slight projection above the mating surface. I was told that on caps that don't have a seal between themselves and the block, that a dab of red Loctite anaerobic sealant helps prevent oil creeping between the mating surfaces of cap and block. Also is a good idea to feel for any nicks, scratches, or burrs that could allow a tiny gap for oil to weep out of. A machinist's fine de-burring stone will clean the surfaces up nicely. Using a file may be too aggressive. As the manual says: "Never file a main bearing cap."
  • FrankvintagefullflowcomFrankvintagefullflowcom Senior Contributor
    Posts: 929

    The early (Fel-Pro P91055-1 winged) and the late (FP P95482-2) versions are dimensionally identical, however, the late "wingless" one has a double lip seal to provide a dust seal on the outboard side. I think it's important to note that the ends of either version aren't cut square on both ends. In both cases, the right hand end of the upper half and the left hand end of the lower are formed with an upward angle at the lip(s), presumably to assure sealing at the interface.

    As pointed out by someone, I like to stagger the ends so that they don't align with the parting line of cap and block. It eliminates the possibility of pinching material at that point.  It looks like the Hudson seal groove is correct for the Chrysler seal but I don't have a Chrysler on hand to check it. There's a little extra room in terms of thickness but I'm sure it's not an issue.


    f

  • Ken U-TxKen U-Tx Senior Contributor
    Posts: 3,223
    Frank,
           I don't see those part numbers listed anymore, but the early rubber winged seal is now Fel-Pro BS 40245, and the later wingless one is Fel-Pro BS40181. The wingless one is @ .060" or about 1/16" larger on it's ID where it rides on the crank seal surface. I know because I just bought both, compared them, and fit them to a 308 crank I have out in the garage. So I will be using the "winged" version (Fel-Pro BS 40245) as it fits snugly around the crank seal journal, whereas the brown wingless one (Fel-Pro BS40181) shows a noticeable gap and falls off the crank seal journal. Yes the ends are formed with an angle where the upper and lower halves mate, as these seals come out of the box. However, the ones I bought from  the HET vendor were ground down somewhat with a grinder of some sort, so that may be why my installed seal set failed to seal.
  • FrankvintagefullflowcomFrankvintagefullflowcom Senior Contributor
    Posts: 929

    I'll need to chase down a Chrysler block and crank for a better comparison. I'm curious about the diameter of the Chrysler seal journal. With the seal halves laying on the bench, the later (brown) version looks to be splayed out somewhat as compared to the other, making it loose on the crank. It would be squeezed inward upon installation, taking up that apparent difference. Seal journal dia. is the key piece of the puzzle. I see ~2.640" for the Hudson.......just don't know the Chry. dim.

    I don't think we can settle for the accuracy of a "ground-down" version. I've heard that many have successfully used it but repeatability of a hand modified part (assuming that it is) is questionable. Too important to leave to chance.

    F

  • Ken U-TxKen U-Tx Senior Contributor
    Posts: 3,223
    On the National seal (Actually Federal-Mogul) website it gives 2.645" for the crank diameter for the National 5414. http://www.fme-cat.com/overlays/part-detail.aspx?pNum=5414&partType=Oil%20Seal%20Kit&brandId=NW
  • FrankvintagefullflowcomFrankvintagefullflowcom Senior Contributor
    edited January 2016 Posts: 929

    After some investigation, I realize that the Chrysler seal does need some modification to fit the Hudson block/main-cap groove. It will protrude about a sixteenth on one end if flush on the other. So.... the groove diameter must be larger on the Chrysler block/cap.

    So.....I stand corrected, in that each "half" needs to have the straight end trimmed to fit, leaving the angled end to provide some "crush" at the lip. Since the Chrysler seal journal dia. is 2.645" and I measure 2.640" on a very "experienced" Hudson crank (virtually identical), it's reasonable to assume that the difference is in the depth of the groove, that is, the Chrysler groove diameter is greater, leaving the ends protruding above flush on the smaller dia. Hudson groove.  Anybody follow that?            Hello?           Hello?            Is anyone out there? Testing....testing. (thump, thump thump) Is this mic on?

    F

  • Ken U-TxKen U-Tx Senior Contributor
    Posts: 3,223
    Hello, Yes, that is what I suspect too. Also when I measured the ID of the brown "wingless" seal Fel-Pro BS40245, it measures about 2.700",nearly 1/16" bigger than the black winged Fel-Pro BS40181.
  • FrankvintagefullflowcomFrankvintagefullflowcom Senior Contributor
    Posts: 929

    Just to finally beat this to death, I have found that the installed ID of both seals is the same. The 40245 was made to replace the original woven "rope" packing in a slightly larger groove. The 40181 was made for a groove diameter that was smaller in the late 318s.

    (I believe Ken reversed those numbers in the previous post)

    Bottom line.......The Brown 40181 won't work because the larger groove won't squeeze the OD down enough to properly contact the crank seal journal in the Hudson.

    Quote from the Fel-Pro tech guy:

    "In regards to the differences in RMB seals, the BS 40245 for the early applications is taking the place of rope seals so the seal needs to be a bit larger due to a larger groove space. Later applications came with a rubber lip seal from the factory so the groove is slightly smaller. The journal size of the crankshafts did not change through the years."

     F

  • Ken U-TxKen U-Tx Senior Contributor
    edited February 2016 Posts: 3,223
    Yes, I reversed the numbers, the 40181 is the brown one that doesn't work. I just installed another 40245 in Kevin's car yesterday. Upon removing the old HET parts vendor supplied (and previously modified) 40245 seal, I found that the ends were ground off almost 1/8", as such the seal was not being compressed into the groove, and the oil leaked around the perimeter of the seal and through the end gap. I put the new seal in without grinding the ends, leaving the factory < and > angled ends in. I just carefully trimmed the "wingy thingies" off. Also the supplier of the modified seal, after I questioned him, said that you need to apply back RTV silicone around the perimeter of the seal, or in the groove, to ensure oil doesn't go around it. So this time I applied the RTV around the seal perimeter. Also I installed the seal so that one end was sticking up about 3/8" on the bock side and the other diametrically opposite on the cap side, so that the mating surfaces of the seal are not even with the mating surfaces of the cap and block. This time I drove the car for 20 minutes, driving 30 mph in 2nd to get the rpms up in the 2500 rpm range for 40+PSI oi pressure. Not a drop to be seen so far........Hope it stays that way for a lonnnnnnng time!
        
  • Ol racerOl racer Senior Contributor
    edited September 28 Posts: 2,263
    F.Y.I.
    Regarding  Mopar 318 rear main seals, I have them in several motors without any drip, however, the latest one I installed really leaked. Apparently  either the Main groove is slightly larger not allowing the Seal to compress to Hudson's 2.500 Journal, or the Seal is slightly off. Going forward, I will use the BEST Brand Seal, either Neopreme or Rope.
  • Ol racerOl racer Senior Contributor
    edited October 10 Posts: 2,263
    Tip on Installing a Rope Rear Seal 'In Chassis'..My Hudson seal drip was annoying so figured simply roll in a Neoprene Seal, however, afterward dripped worse. Like I mentioned above, crank seal journal may have minute scratches, or the cap groove is slightly larger.
    After researching learned a Rope Seal is far more 'forgiving' however modern Rope Seals in gasket sets (except Best Seals) are made from inferior material & unreliable, thanks to E.P.A. Reg's.  Fortunately, I had an old Gasket Set with 'old material' Rope seal, but had to figure how to roll it up over the crank...Here is what I did...

    Simply take a 12Pt curved wrench (also called starter, hoop, or half moon wrench, but needs to be a 12Pt) then patiently loosen the three 1'4" bolts right above the crank, but do not unscrew them too far and pry back the plate slightly. I didnt have a 12Pt so I made a wrench. You need put a slight bend on handle to clear a rear Plate Bolt at 3:00 and 9:00. (Pic below)

     Next soak the Rope Seal overnight in light Oil. (Yes, need to soak old material) then form fit the Seal in the Main Cap using a large socket or Pipe. I formed it to be .029 to start in groove then remainder was .031 - .034 depth. Next, buy a cheap Sneaky Pete Tool (Lisle #27000), use the Corkscrew provided to pull the old seal out while rotating crank, then discard the 3 tiny Lisle 'grab' attachments designed to pull the new Seal up (which wont work), and instead, insert the Lisle piano wire above the crank then hook the end of the wire into the Rope Seal as far as poss & aprx 1/4" back from Seal end. Next, start the Rope Seal into the upper groove then rotate the crank while pulling on the piano wire handle. (suggest practice with pulling the old seal around). Lastly, trim the top Seal Ends flush then place a dab of Black Permatex RTV on each end and re tighten three top bolts..

    For the Cap, Fit the Seal in groove tightly and leave .015 protrude out of Cap providing a 'crush' when Cap is torqued 75 - 80lbs.

     Ive done it twice now while lying on my back with no drip.... The key thing is dont back the 1/4" screws all way out and be patient fitting the wrench on the bolts. Once get the rythm its pretty ez...This install was in Stepdown Hudson with Hydromatic.

    As a Foot Note: The Best Gasket Co Graphtite Rope Seal measured .030 before fitted in Main Cap groove so probably would pull up easier over the crank. It requires pining in the Cap so elected installing N.O.S Rope.

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  • Geoff C., N.Z.Geoff C., N.Z. Senior Contributor
    Posts: 3,286
    So you do all this from under the car, with the flywheel in place???
    If you're stuck in a hole, stop digging.
  • Ol racerOl racer Senior Contributor
    edited October 10 Posts: 2,263
    YES, I did....Actually took me longer to type process (one finger)... Shared in hopes it helps some else with annoying rear seal drip..
  • Geoff C., N.Z.Geoff C., N.Z. Senior Contributor
    Posts: 3,286
    Thanks muchly.   That's the next problem I have to tackle on my Hornet.
    If you're stuck in a hole, stop digging.
  • Ol racerOl racer Senior Contributor
    Posts: 2,263
    Attached picture showing hooking Seal to slide up over the Crank after seal compressed using Main Cap.  Note The Sneaky Pete Tool is actually reversed from theit instruction since the 'Fingers' provided slip right off.

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