Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

To do rear main seal or not...

Discussion in '1982-Present GM Diesel' started by tRustyK5, Sep 4, 2006.

  1. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,169
    Likes Received:
    1,372
    Location:
    E-town baby!
    Just got my clutch and flywheel off and got a good look at the back of the pan/crank area (rear of block as well) and It doesn't appear that my rear main is leaking. Above the bell mounting area of the block is dry, so it's definitely not leaking at the back of the valve covers. The wettest part I see is where the pan meets the block directly below the centerline of the crank. Directly above this part is damp, but I don't see any telltale signs that the oil is running downwards from there. It really looks like the round seal at the back of the pan is where the leak is coming from...

    So, do I take the pro-active approach and do the rear main anyways or just get a pan set? Second Q is does anyone make a one piece rubber pan gasket set that anybody knows of? I recall having a hell of a time with my old sbc trying to get it to seal with one of those 4 piece sets...but the one piece rubber gasket was a pleasure to work with.

    Rene
     
  2. BKinzey

    BKinzey 1/2 ton status

    Joined:
    Jan 13, 2006
    Posts:
    3,145
    Likes Received:
    0
    Location:
    Hollywierd, CA
    How many miles on it.

    Naw, screw that:crazy:

    You know the drill:rolleyes::rolleyes:

    If you don't replace it you'll get a leak within 3 months:doah:

    If you do you gamble you'll find something else that "maybe" should be replaced:what: Or you'll screw up, loose, or whatever, the new gasket and find out you had the last one in North America for "At Least A Week....":haha::haha:


    Throw caution to the wind. Replace it while you are there. You know you will:D:D:bow:
     
  3. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,169
    Likes Received:
    1,372
    Location:
    E-town baby!
    Yeah, pretty much a given I'll replace it. Just lookin at the enormity of the project right now and had an insanity moment. Found it odd that it wasn't the rear main leaking though.

    Rene
     
  4. 75k10chevy

    75k10chevy Registered Member

    Joined:
    Oct 7, 2005
    Posts:
    39
    Likes Received:
    0
    Location:
    Liberty Lake, Washington
    As far as i know there is only the 4 piece oil pan gasket, I tryed to find a single piece when I changed mine but wasnt succesful. If the rear main is that pos rope type I would replace it with the rubber type while the pan is off. Mine was dumping oil out the rear main and when I went to replace it I found that a 1/4 of it was missing:doah:
     
  5. savagek5diesel

    savagek5diesel 1/2 ton status

    Joined:
    Nov 20, 2003
    Posts:
    310
    Likes Received:
    0
    Location:
    Redding California
    'bout 70% sure they do make a one peice pan gasket now, can't remember where i saw it though. I'll look for it again.
     
  6. cegusman

    cegusman 3/4 ton status

    Joined:
    Apr 25, 2001
    Posts:
    6,793
    Likes Received:
    0
    Location:
    Houston/Katy, Tx
    I don't think its a 4 piece, If I remember correctlly its a 2 piece. The main cork piece that goes allthe way around the oil pan then the rubber half moon seal ant the crank.
     
  7. colbystephens

    colbystephens 1 ton status GMOTM Winner

    Joined:
    Feb 24, 2005
    Posts:
    10,924
    Likes Received:
    20
    Location:
    Oregon
    mine wasn't cork, but it was this style. mine leaks...
     
  8. joez

    joez 1/2 ton status

    Joined:
    Oct 21, 2003
    Posts:
    2,512
    Likes Received:
    0
    Location:
    New Lenox, Illinois
    My old K5 had an all rubber 2-piece gasket like this, so they do exist.

    Rene, i dont remember, but did you change the rear main when you did the motor swap?
     
  9. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,169
    Likes Received:
    1,372
    Location:
    E-town baby!
    Nope, when I got that motor it was dry and clean stem to stern and had not been sitting long. It stayed that way leak wise until the road trip to Moab. I think 22 hours of 2600-2700 rpm each way took it's toll, because by the time we got home it was getting wet and oily underneath. :doah:

    I'll be getting the gaskets in another week and a half or so, so if anyone has any brand names or part numbers for the better gasket sets please post up...

    Rene
     
  10. dieselponyexpress

    dieselponyexpress 1/2 ton status

    Joined:
    Jan 26, 2004
    Posts:
    220
    Likes Received:
    0
    Location:
    Germany
    maybe too late:

    there was an old article at The Dieselpage com many years ago regarding the pan seal kit. Conclusion was to use only the rubber seal from the 2 peace kit, discard the paper/cork one and using sealant instead.
    I've done it 6 years and 80.000mls ago and no leaks.

    Walter
     
  11. colbystephens

    colbystephens 1 ton status GMOTM Winner

    Joined:
    Feb 24, 2005
    Posts:
    10,924
    Likes Received:
    20
    Location:
    Oregon
    has anyone come across the rubber oil pan gasket?
     
  12. colbystephens

    colbystephens 1 ton status GMOTM Winner

    Joined:
    Feb 24, 2005
    Posts:
    10,924
    Likes Received:
    20
    Location:
    Oregon
    anyone found the rubber pan gasket out there? ... rene - what did you use and did it work well??
     
  13. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,169
    Likes Received:
    1,372
    Location:
    E-town baby!
    I got the Fel-pro pan kit. Extra heavy sorta paper gasket that worked quite well IMO. I used a gasket glue and glued the gasket down to the pan itself and let it sit overnight, then applied the same glue stuff to the engine side of the gasket, pushed the pan into place and buttoned it up. No leaks...

    Rene
     
  14. colbystephens

    colbystephens 1 ton status GMOTM Winner

    Joined:
    Feb 24, 2005
    Posts:
    10,924
    Likes Received:
    20
    Location:
    Oregon
    cool. that's what i'll do then. :) any tips on the rear main? i didn't do mine well - i think that i didn't use enough rtv on the main caps for fear of using too much. any thoughts/tips??
     
  15. CDA 455

    CDA 455 3/4 ton status

    Joined:
    Jun 2, 2006
    Posts:
    8,598
    Likes Received:
    0
    Location:
    43rd State

    Hey Colby, where are you in your Avatar?
    I'll guess AZ, and if so, where?
    That looks like a cool place :D !
     
  16. colbystephens

    colbystephens 1 ton status GMOTM Winner

    Joined:
    Feb 24, 2005
    Posts:
    10,924
    Likes Received:
    20
    Location:
    Oregon
  17. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,169
    Likes Received:
    1,372
    Location:
    E-town baby!
    The big key is to add a very thin film of sealant between the block and the rear main cap...outwards from where the two halves of the seal meet. Without that little bit of sealant there oil will weep between the block and the cap.

    You definitely want to go very thin there...

    Rene
     
  18. colbystephens

    colbystephens 1 ton status GMOTM Winner

    Joined:
    Feb 24, 2005
    Posts:
    10,924
    Likes Received:
    20
    Location:
    Oregon
    so sealant, not rtv? my haynes said rtv, so i just dabbed some next to the seal. would it be better cover the whole cap w/ a small amount of sealant?
     
  19. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,169
    Likes Received:
    1,372
    Location:
    E-town baby!
    I used sealant and it worked fine. You need to run a line of it outwards from the seal to the edges of the cap. Otherwise the seal is working fine but the oil is getting between the cap and the block.

    Rene
     
  20. colbystephens

    colbystephens 1 ton status GMOTM Winner

    Joined:
    Feb 24, 2005
    Posts:
    10,924
    Likes Received:
    20
    Location:
    Oregon
    hmmm, so i could just pull the cap, cut out the rtv, put some sealant in there and be done with it? no need to redo the rear main seal, i suppose! that would save some time. thanks for making my brain work. :D
     

Share This Page