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Transmission oil for '48 Champion??

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  • Transmission: Transmission oil for '48 Champion??

    Ordered the shop manuals yesterday for my 48 champion, but in other research I've seen mention of transmission oil for this car. Didn't much consider fluids for it since it's a 3 speed manual with overdrive. Maybe this is one of the reasons for the overdrive being temperamental is oil is low.
    anyone point me in thebdirection of how to check the level and where to add fluids to it if needed(until my shop manuals arrive)? Might solve my overdrive problem

  • #2
    I don't have my manuals close at hand, so instead of answering your question, I will answer some questions which you did not ask.

    There is a separate manual for the Borg-Warner overdrive. If I remember correctly, it covers the transmission in several makes of cars, not just Studebaker.

    The oil in the overdrive is checked and filled separately from the transmission.

    There are 2 wires for the overdrive solenoid on the overdrive. They must be installed on the correct terminals. If reversed, the solenoid will try to move in the wrong direction, so the overdrive will not engage.

    When the car is driven in overdrive, the transmission "free wheels", meaning that there is no engine braking. I lock the overdrive out (pull out the dashboard knob) before driving around town, so that I do have engine braking when needed. Also think about this before going down a steep hill -- only the brakes can slow the car.

    Never, ever, even think of locking out the transmission (pull out the OD knob) while the car is moving. While it can be done IF YOU KNOW HOW, you are risking destroying the overdrive if you do it incorrectly. It is OK to engage the overdrive (push in the knob) with the car moving.

    If you can't find the 90-weight oil called for in the transmission and overdrive, you can use straight 40-weight engine oil as a substitute. I don't know how easy that is to get now. "Back in the day" this was used in highway coach engines and standard transmissions. I still have a small supply obtained from a bus company.

    You will like driving with the overdrive. It makes the difference between a city car and a highway car.

    Bill Jarvis
    Last edited by Greenstude; 06-27-2020, 12:14 PM.
    Bill Jarvis


    • #3
      The very IMPORTANT thing to look for in Manual Transmission Oil is the GL rating, it MUST be GL-1 Straight Mineral Gear Oil found at Farm Type Stores (Tractor Supply) and any NAPA Store.
      Purchase or Order a Gallon Can. It usually comes in 85/90 Wt.

      Make SURE the Main Case and the Overdrive Case have leveled and are BOTH Full to the Check Plug before re-installing either Plug. They Can flow from and to each other.

      It is likely your Oil has been in there for a VERY Long Time, so just Drain both Cases and refill with AP Rating GL-1.
      Last edited by StudeRich; 06-27-2020, 10:15 PM.
      Second Generation Stude Driver,
      Proud '54 Starliner Owner


      • #4
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        I believe your question was HOW? Notice 4 pipe plugs in above picture. Two lower ones are drain. Upper two are fill. Simple!
        Whenever I purchase a new vintage vehicle one of the first things I do is change all fluids. Who knows what previous owner put in there?


        • #5
          Thank you Bob (rbisacca) for finishing where I left off!
          I could not find my saved Word Doc. with a copy of the last SDC Forum String where the NAPA Part Number was mentioned.

          This is a Very Good thing to remember; 65-201

          I spent at least half an hour searching the NAPA Website for every Transmission Oil WORD I could think of, and NEVER found Transmission Oil.
          It seems NO Amount of Common Sense EVER works on these "gamer kid' developed Websites.
          Second Generation Stude Driver,
          Proud '54 Starliner Owner