rear end fluid?

SirmodSirmod Posts: 15Member
I've just bought a 1930 Hudson Super 8 and I'm in the process of dusting off the cobwebs.  Part of that is changing all the fluids.  Would somebody please tell me what I should use in the differential?  

Comments

  • GeoffGeoff Posts: 4,462Senior Contributor
    140 gear oil
    If you're stuck in a hole, stop digging.
  • ToddhToddh Posts: 276Member
    GL-1 won’t damage any brass/bronze thrust bearings in your differential.  
  • GeoffGeoff Posts: 4,462Senior Contributor
    There are no bronze components in this rear end.
    If you're stuck in a hole, stop digging.
  • SirmodSirmod Posts: 15Member
    What about using 80/90 extreme pressure hypoid gear oil?  I have a 48 Chrysler and that's what is recommended for it and since I have about 3 quarts of it, would it be ok to use that?
  • GeoffGeoff Posts: 4,462Senior Contributor
    Should be okay, but you may have leakage if  you still have the original felt seals.
    If you're stuck in a hole, stop digging.
  • SirmodSirmod Posts: 15Member
    I'll be checking on that soon.  I've noticed a fair bit of wetness on one of the backing plates so I'm guessing a wheel seal is leaking.  
  • SirmodSirmod Posts: 15Member
    So I've got both axle out now and I have a couple questions. 
    Before I pulled off that retainer housing. ( not sure of the proper name) I checked the axle end play.  According to the "instruction book"  that I have for 1931, it says there should be between .005 and .010 end play.  I have, right axle .067 left axle .066.  On the right side axle there was only a couple thin home made gaskets.  On the left side there was one home made gasket and one shim (.003)  I put the retaining housing back on without anything on both sides and I'm down to .039 and .038.   So the only variable that I can see that can be altered is to drive the axle bearing down closer to the taper end of the axle about .050 th.  Then by the time I add a gasket and a home made shim I should be within tolerance.  Which direction is that bearing put on to the axle?  Is it up against a lip?  It looks to me there is a straight section on the axle close to a quarter inch, before it starts to taper down, so my method would work, assuming the bearing will move in that direction and there wouldn't be a lip stopping it.  Of course my obvious question is why is there so much end play in the first place?

    Another question I have is in regards to that felt seal that is in the retainer housing.  Is that still available?  I have some felt that is about that thickness ( 1/4")  so I might make my own.  But is it important to get the inside diameter to a particular dimension in relationship to the axle diameter?  Do I need to prelube the felt with anything?  
  • GeoffGeoff Posts: 4,462Senior Contributor
    You are barking up the wrong tree!   The axle bearing has a tapered centre, hence there is no way you can drive it further on.  You will have to build up the inner thrust buttons with hardcraft, and re-grind flat, then set the end play shims under the bearing caps..  It is essential that you have both wheels off the ground for doing this.   Yes, you can cut new felts, or better, go to a bearing and seal shop and get a modern seal to replace the flat one.
    If you're stuck in a hole, stop digging.
  • SirmodSirmod Posts: 15Member
    So when you say to build up the thrust button with "hardcraft"  are you basically talking about using a mig welder to add on to the end of the button?

    As for the felts, I'm guessing just make the ID of the replacement felt a very tight fit, right?  When you speak of using a modern seal, do you have something specific in mind?  A regular style of seal won't work obviously since the area it needs to go in is U shaped.  So it would have to be a solid rubber/neoprene so it could bend and be pushed into that U recess.  Does someone make such a seal? 
  • GeoffGeoff Posts: 4,462Senior Contributor
    Hardcraft is an arc welding rod, very hard and wear resistant.  Could use stainless too.    The recess in the housing is round, not U-shaped.  You need to measure the outside of the original retainer, and the axle  diameter, and get a modern seal that fits.  
    If you're stuck in a hole, stop digging.
  • SirmodSirmod Posts: 15Member
    This is what the one on my car looks like.
  • GeoffGeoff Posts: 4,462Senior Contributor
    That is the outer seal.  it is the inner one you need to pay attention to.  The outer one you can certainly cut a new felt. 
    If you're stuck in a hole, stop digging.
  • SirmodSirmod Posts: 15Member
    Geoff said:
    That is the outer seal.  it is the inner one you need to pay attention to.  The outer one you can certainly cut a new felt. 
    Yep, I've already ordered the inner seals a couple days ago. 
  • Jon BJon B Posts: 7,420Administrator
      Geoff, I don't mean to hijack the thread, but when did Hudson begin using (or did they ever use) bronze components in the rearend.  I have a '37, and had recently changed to GL-4 gear oil, not wishing to destroy any bronze bushings.  Maybe I was worrying for nothing....
  • GeoffGeoff Posts: 4,462Senior Contributor
    From the first Terraplane, they used bronze cup thrust washers in the back ends.   When they changed to the Dana rear end in '53 they used all steel components.  
    If you're stuck in a hole, stop digging.
  • GeoffGeoff Posts: 4,462Senior Contributor
    Most Penrite oils will state if they are safe for copper-based components. 
    If you're stuck in a hole, stop digging.
  • Jon BJon B Posts: 7,420Administrator
    Geoff, would the rear end have had bronze components in 1937?  (As I said, I am using a GL-4 type of lubricant, just to be on the safe side, but I'd still be curious.)
  • GeoffGeoff Posts: 4,462Senior Contributor
    Yes, all Hudson and Terraplane from 1932 thru 1952 had bronze cup washers in  the spider gears.
    If you're stuck in a hole, stop digging.
  • Jon BJon B Posts: 7,420Administrator
    Thanks for confirming that, Geoff.  I don't recall using GL-4 type rear end oil over the past 42 years (since my rear-end was rebuilt after a catastrophic failure on a long-distance trip).  I hope I haven't damaged the cup washers.  We'll see....
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