sd33 rear crank case oil seal

Discussion in 'Diesel Tech' started by zen, Mar 15, 2006.


  1. zen

    zen Farmall Cub

    Joined:
    Mar 9, 2006
    Messages:
    344
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    london
    its leaking,atleast it looks like it is,cos of where the oil drips,

    any sneaky way to change it without complete engine out and strip down??
     
  2. bbellster

    bbellster Farmall Cub

    Joined:
    Oct 8, 2004
    Messages:
    141
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Lafayette, IN
    I just replaced mine less than a week ago and its still leaking :mad: I think that it may be due to the fact that the seal did not protrude from the bearing cradle the 0.5 mm specified in the manual. I ruined the old seal taking it out and didn't have any alternative other than putting the new one in even though it was out of spec. SO, I have no idea what to tell you. I have heard of others replacing seals w/o success. :confused:
    But, in response to your question, yes it can be done in vehicle, and it is really straight forward. Just remove the pan, and rear main cap. The cap is a little tricky to get out, but you can use a slide hammer or a bar that will span the cap and some spacers between each end and the block. With a hole drilled in the appropriate spot, place a bolt through the bar and thread it into the cap. tighten the bolt to pull the cap. Once the cap is removed, you can push on one side of the upper seal, and it should slide around and out. Put in the new one in reverse order. Will it seal?? donno
    BB
     
  3. dick ardrey

    dick ardrey Binder Driver

    Joined:
    May 11, 2004
    Messages:
    907
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    nashville tn
    It has been done-- drop the crank bearings and get 1/8 + " of drop and run the top of the seal around the top of the crank.
    replace the bearing caps while doing the lower half and we used
    some kind of GREAT STUFF to seal the crack. The real fix was to releave the crankcase pressure buildup ( as we removed the draft tube) You want '0' pressure in the pan!! If you have a lot of blow by from old rings or a new turbo ect.. you will cause a rear seal leak from a pressure buildup. I would try a oil inlet, strainer, cap type (flame arrester) to increase the vent of the valve cover first.

    In my case -- we are using 2 flame arresters screwed into the valve cover and then 1/2"hoses to the air intake BEFORE the turbo (replacing the draft tube)(after 2 big air filters).

    lazer
     
  4. zen

    zen Farmall Cub

    Joined:
    Mar 9, 2006
    Messages:
    344
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    london
    thanks..real glad i asked,as was going to remove engine..:p

    i assume you pulled down crank withrods still connected,i guess it will only move a fraction anyway with the trans still connected??

    are there any mods that can be done to engine breather on side of engine.(on mine rocker cover breather has 2 pipes,one to airfilter,one to side of engine.)
    at present blowby isn't to bad,but soon to have turbo fitted,so expecting it to get worse and loose more oil??
     
  5. zen

    zen Farmall Cub

    Joined:
    Mar 9, 2006
    Messages:
    344
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    london
    oh..i assume one does the front one too at the same time??or leave it alone if fine??
     
  6. John Donnelly

    John Donnelly Administrator Staff Member Administrator Moderator

    Joined:
    Mar 5, 2001
    Messages:
    13,953
    Likes Received:
    33
    Trophy Points:
    48
    Location:
    Woodburn, Oregon
    It is not necessary to lower the crankshaft to change the seal. Leave your main bearings alone, unless when you drop the rear cap you see excessive wear, in which case you might as well do an in-frame overhaul.

    What is necessary is patience, and the correct parts. Use a genuine Nissan seal, or one recommended by Noordeman Diesel Spares. Do not use some cheapo made in China seal. All the leaky seals I have seen have been due to cheap parts.

    Leave the front crankshaft seal alone if it isn't leaking.

    Do not use RTV, "Right Stuff" or any other sealant on any of the parts when you re-assemble the engine. All sealants will do is promote leaks. If you use quality parts, and torque things properly, sealant isn't necessary.

    The SD33 is machined to aircraft tolerances when it was built. The flatness and quality of surface finish on all the parts in an SD33 is a nice sight to see.

    Hence, no goop needed.

    -John
     
  7. Marlon

    Marlon Farmall Cub

    Joined:
    Jun 19, 2003
    Messages:
    63
    Likes Received:
    0
    Trophy Points:
    6
    Location:
    Sherman, IL
    John,
    Is this job any easier with the tranny out? Thanks.

    Sincerely,
    Marlon

    1976 Traveler Diesel (1 owner)
     
  8. John Donnelly

    John Donnelly Administrator Staff Member Administrator Moderator

    Joined:
    Mar 5, 2001
    Messages:
    13,953
    Likes Received:
    33
    Trophy Points:
    48
    Location:
    Woodburn, Oregon
    No. Once you are under there, and look at it a bit more closely, you will see why. The transmission is not in the way in any fashion.

    Probably the only virtue of the IH 10-1/4" long input shaft.

    Dieselin',

    John
     
  9. BinderMark

    BinderMark Farmall Cub

    Joined:
    Mar 20, 2003
    Messages:
    67
    Likes Received:
    0
    Trophy Points:
    6
    Location:
    Louisburg, KS.
    SD33 front crank case oil seal

    What about the front seal? How hard is it to replace while the engine is in place in the truck? Does a person need a special puller to get the pulleys off and does the front cover need to come off? Does the radiator need to come out to make it easier or will it come off without that extra work. Lots of questions.
    Thanks for the help.
    Mark
     

Share This Page