1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Dana 20 Speedometer Drive Gear

Discussion in 'Intermediate CJ-5/6/7/8' started by houleyh, Sep 22, 2020.

  1. Sep 22, 2020
    houleyh

    houleyh New Member

    Quebec
    Joined:
    Jun 30, 2020
    Messages:
    42
    Hi, My speedometer has been far off since I own this Jeep. (It reads way down). Got a new cable, a new speedo. It was still down and worked for a while. Now it barely working so I decided to look on the Transfer case side of it.

    Th Driven gear is perfect. Full steel and 16 teeth
    The drive Gear is plastic, Yellow. Does not look worn from the outside. Maybe 6-7 teeth (See picture)

    The yellow plastic drive Gear almost turns freely. Sometimes turn with the driving shaft, skips aften and completely stops turning when a light pressure is applied on it wit a finger. So the drive Gear is loose.

    1- What keeps the Drive Gear tight with the output shaft other than pressure?
    2- Is the Drive Gear still available on the market?
    3- Is it easily replaceable on the car? Do we need special equipment? New seals? New Shims, Speedo Drive Gear.jpg etc.

    Thanks for helping

    2-
     
  2. Sep 22, 2020
    houleyh

    houleyh New Member

    Quebec
    Joined:
    Jun 30, 2020
    Messages:
    42
    The rest of the items to complete the puzzle are the SW 448856 driven Gear. Preliminary researches 20200922_175340.jpg on internet says that the internal gear (Drive Gear) should be 447537. How come The driven gear is full metal. Info says it was used until 71 on Dana 18 TC and I have 1 1974 with Dana 20? Thanks for helping
     
  3. Sep 22, 2020
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    Speedometer “gear sets”were manufactured as a single drive gear with various associated driven gears.
    In other words the driven gears of various ratios must be mated to a specific drive gear.

    The earliest gear sets prior to 1964 had limited ratios available.
    Some drive gear sets are more versatile than other drive gear sets.
    All speedo gear sets used in Jeeps prior to 1970’s were steel gears made by Stewart Warner.
    It is best to identify them by the SW number.
    During the 1970’s nylon gear sets came into production.
    I’m old school and prefer the steel gear sets.

    You cannot mix match earlier series of drive gear sets with later series of drive gear sets.
    You can use any matched gear sets in most any transfer case you want. Except.....
    You cannot mix IH speed gear sets with Jeep gear sets unless you also change the rear bearing cap.
    IH gear sets run in reverse direction as compared to Jeep gear sets.

    Matching a speedo gear set to your Jeep is mainly dependent on differential ratio and tire diameter.
     
  4. Sep 24, 2020
    CharlesC83

    CharlesC83 Wrench

    Lewiston Idaho
    Joined:
    Sep 2, 2020
    Messages:
    35
    The speedometer bounced on my Jeep also. My speedometer gear did that same issue yours has on my 74. The plastic portion could spin on the metal sleeve. I removed it, and it is a plastic gear bonded to a metal splined sleeve. The glue from the factory broke loose. I could not find a readily available aftermarket gear, let alone a replacement period even used online at the time. My father and I removed the gear cleaned all the oil off and cruised to the hardware store and bought strongest plastic safe glue they had. We glued the plastic gear back into place and let it dry over night. It was some sturdy stuff, it's been holding for 8years or so. Bouncing speedometer solved.

    My gear is yellow just like yours.
     
    Desert Runner likes this.
  5. Sep 24, 2020
    houleyh

    houleyh New Member

    Quebec
    Joined:
    Jun 30, 2020
    Messages:
    42
    Thanks, Makes a lot of sense. Will take it off and report. YH
     
  6. Sep 24, 2020
    Desert Runner

    Desert Runner Member 2024 Sponsor 2022 Sponsor

    Hickory, Pa
    Joined:
    Sep 11, 2005
    Messages:
    807
    Same here Speedometer bounced, and I foune the yellow gear just slipping. But I had a 2nd D20, so I swapped the tail shaft housing. I'll have to try your glue fix, so I can have a spare.
     
  7. Sep 24, 2020
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
    Joined:
    Sep 23, 2002
    Messages:
    12,529
    Can you quantify this? I’ve torn apart hundreds of Scout and Jeep 20’s, used speedo gears from both and never seen any cut reverse one from the others.
     
  8. Sep 25, 2020
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    Nick thanks for your reply.
    That statement was based on the only IH transfer case that I’ve ever dealt with a couple years back. So sorry if it’s was misleading.

    The transfer case in question was an IH Dana 20, factory twin transfer case from the late 60’s Scout 800
    It had a steel SW speedo gear set.

    I should have a pic of two in my imgur account but I can’t get into that account.
    So I’m going on old memory here but I seem to recall the SW gear set had a reverse cut and the Speedo cable entered into the rear bearing cap from the top instead of bottom as typical on a D20.

    Here : luckily I just found a scout 800 rear bearing cap on eBay: Scout II 800 Dana 20 Rear Output Shaft Housing Bearing Retainer Transfer Case | eBay
     
  9. Sep 26, 2020
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
    Joined:
    Sep 23, 2002
    Messages:
    12,529
    I didn’t look at the pics but intuition makes me think maybe you are thinking of where the speedo drive is located on the housing? Both the 18 and 20 IH Scout speedo drive is roughly 180 degrees from the Jeep versions. The gears have the same directional cuts that I’ve dealt with. As you intimated (andothers have) the tooth direction and count must match for the various axle ratio and tire size.
    We used to take 20 rear output’s and rob the yokes, speedo gears, and setup shims and toss the rest in scrap as no one wanted those parts. We would save a few housings and shafts and they would sit on the shelf for years.
    We wanted the shims before they were being reproduced. The .003” were especially needed as they were almost always damaged during disassembly.
     
  10. Sep 27, 2020
    ROBERT H SWARTOUT

    ROBERT H SWARTOUT New Member

    KALAMAZOO MI
    Joined:
    May 16, 2020
    Messages:
    20
    my 74 did the same. then started working again but speed is still off. I left it alone after searching for gears not found.
     
  11. Sep 28, 2020
    houleyh

    houleyh New Member

    Quebec
    Joined:
    Jun 30, 2020
    Messages:
    42
    Solved! The Drive Gear was loose on it's shaft. Disassembled the rear output housing, Got everything apart and Epoxyed the Gear. Works like a charm for now. Just wait to see if the Epoxy can last. Thanks to all the contributors. Put some pictures of the project. Speedo Drive Gear Loose1.jpg Speedo Drive Gear Loose2.jpg Speedo Drive Gear Now Glued.jpg
     
    CharlesC83 likes this.
  12. Sep 28, 2020
    CharlesC83

    CharlesC83 Wrench

    Lewiston Idaho
    Joined:
    Sep 2, 2020
    Messages:
    35
    Great! Mine has been glued for 10 years or so. Not a ton of miles, but a while.
     
  13. May 14, 2021
    Armando Acosta Valdés

    Armando Acosta Valdés New Member

    Baja California
    Joined:
    May 14, 2021
    Messages:
    1
    Hi, what´s the size of the socket you used to remove the speedometer sleeve? I tried to remove it with a 7/8" but i couldn´t because the thickness of the socket
     
  14. Jun 3, 2021
    leetmo

    leetmo New Member

    Northern Colorado
    Joined:
    May 1, 2021
    Messages:
    1
    It's 7/8". But you may have to sacrifice one on the bench grinder to get it to fit.
     
New Posts