No announcement yet.

twin traction

  • Filter
  • Time
  • Show
Clear All
new posts

  • twin traction

    1963 hawk jet thrust R-1 ....I am cleaning and flushing my rear differential and I have a few questions...The number tag 45c is on my case, what does that denote?
    And when replacing the gear oil in my twin traction Hawk the manual calls for special studebaker twin traction gear oil, what should I use?
    Joe Heaney

  • #2
    45C - basically you have a twin traction. look in the shop manual for the difference between the various styles of the TT unit (that's what the tag is telling you)

    Either use a GM limited slip additive in your gear lube, or a lube like Redline that specifically states on the package that it is suitable as-is for use in limited slip differentials.


    55 Commander Starlight
    55 Commander Starlight


    • #3
      The 45C to you indicates you have a Twin Traction axle, that's it!

      To a mechanic repairing it it says that the "ramps" are 45 degrees, to get proper repair parts if needed.

      The oil should be a good brand like Valvoline etc. 85W-90 Wt. GL5 for standard and limited slip axles. You should add a 4 oz. bottle (black liquid) of friction modifier for limited slip, found at Jeep/Dodge dealers even Ford or GM will work or aftermarket parts store stuff, but I shy away from the latter if possible.

      Flushing is not recommended! If you must, be sure all traces of solvents are removed, use brake clean and dry throughly last.

      Studebakers Northwest
      Ferndale, WA
      Second Generation Stude Driver,
      Proud '54 Starliner Owner


      • #4
        I asked Garth Wilson (Stude mechanic for about 50 years)what to put in my twin traction rearend and he said 80-90 gear oil. And stressed it must say hypoid on the label. He told me to try it without friction modifiers first and if it acted funny to go ahead and put limited slip additive in. He said at the Stude dealership they found out that some needed the additive and some would act up with additives. Take it for what it's worth.


        • #5
          No big deal here...
          Most gear lubes are posi/limited slip frendly these days.

          Just as you would look at a menu at your local the info on the bottle.



          • #6
            The friction modifiers allow the clutches to slip. Hard-core road racers won't use it as all as they say it only quickens the wear & gives up some traction. If you don't use it, you'll likely get noise when the clutches break free in turns & maybe even some jerky feel in the back (like a 4WD negotating a tight turn) depending on how tight it's set up & what the break-away torque is.

            OEMs installed the friction modifier primarily for noise, comfort, etc.

            Use it or not...doesn't matter much except for noise.

            Daddy always said, if yer gonna be dumb, you gotta be tough & I'm one tough sumbitch!
            Daddy always said, if yer gonna be dumb, you gotta be tough & I\'m one tough sumbiatch!