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Overdrive Problem

Discussion in 'Early CJ5 and CJ6 Tech' started by scott milliner, Nov 3, 2015.

  1. scott milliner

    scott milliner Master Fabricator

    It's a brand new Advanced Adapters Overdrive. I drove the Jeep to work today to try out how it drove. Worked great, until I drove it home. Now it pops out of direct drive. Doesn't make any sense. The instructions give a measurement how far the gear is suppose to extend out the housing. Mine is out .080" farther , but doesn't bind. Now I'm thinking it could be the Novak Main Shaft. Could it be that the Main Shaft is walking forward? Could a SM465 shaft move forward? I had the transmission professionally rebuild about a year ago. Anyone know anything about the SM465? This sucks. This is the second overdrive that did this.
    I called AA. They blame Novak.
     
  2. oddfirejeeper

    oddfirejeeper Active Member

    scott,
    i've heard that the front bearing is something to look out for?? i guess you can't go by year of the trans but by the thickness of the bearing to get the wrong one? i may run into this when i install my 465 here soon. would that wrong bearing push the shaft back creating the overdrive to not engage properly? there is a guy on ebay that has that info on his ad when buying a rebuild kit. something to look into i guess. maybe someone with some knowledge will chime in soon.
     
  3. Dave B

    Dave B Frankenjeep '67

    Is this your installation instruction you referred to? --Before assembly, you must verify the proper location of the gear assembly. This measurement of .677" is taken from the case to the top of the planetary.
     
  4. wheelie

    wheelie beeg dummy 2024 Sponsor 2023 Sponsor

    Scott, I seem remember some discussion here about excessive endplay in the transmission mainshaft possibly causing issues with an OD. Not sure where, here, I read it and it may have even been during your previous OD situation. Maybe I can find it......
     
  5. scott milliner

    scott milliner Master Fabricator

    My measurement was .757"out to far and would help with the engagement. The new overdrive does work better then the old on. The old one, I couldn't even let the clutch out with out it popping out. This one does it under heavy loads.
     
  6. nickmil

    nickmil In mothballs.

    Are you using the "thick" adapter with the spud shaft or the thin adapter with a one piece mainshaft to the transfer case?
     
  7. jeepermc

    jeepermc Active Member

    I'd inspect everything for play. Mine had the same symptoms recently. I finally fixed it last night by replacing the main bearings in the barrel gear... That's not likely your issue, but if things move around (mine was) they pop out of direct. I tried all kinds of different shims before I investigated further and found the bearing issue.
     
  8. scott milliner

    scott milliner Master Fabricator

    1" Adapter.
    I do have a thought. I'm wondering if the snap ring on the output bearing is missing. I talked to Novak and they said. The main shaft can't move that much.
     
  9. Posimoto

    Posimoto Hopeless JEEP Addict

    Don't buy AA's opinion that it's the Novak parts. AA is really great about passing the buck. I know this from personal experience with them.
     
  10. colojeepguy

    colojeepguy Colorado Springs

    But if he's had two units exhibit the same symptoms, that would lead me to look in a different direction.
     
  11. scott milliner

    scott milliner Master Fabricator

    I took the overdrive off. The synchro ring seized onto the planet hub. When I took the overdrive gear off. I found I left shims on the shaft from Herm to try to fix his faulty overdrive. There wasn't enough clearance. That's probably why it worked most of the day until it got too hot and not engage all the way. Well. Rebuild and try again. :mad:
     
  12. scott milliner

    scott milliner Master Fabricator

    Overdrive works now. It seems you need the .677 measurement for the overdrive to work. To get this I machined .030 off the Spacer Washer. That's the washer at the base of the gear, between the gear and the output shaft.
     
  13. uncamonkey

    uncamonkey Member

    I was of no help with your problem as every one of them I put on worked fine. Happy you got it working properly.
     
  14. Dave B

    Dave B Frankenjeep '67

    Good to hear you have a working OD. Glad I have OD; especially for street driving, and reverse with the granny-low T-98 transmission!
     
    Last edited: Nov 14, 2015
  15. tarry99

    tarry99 Member

    Good Job Scott...........
     
  16. lowenuf

    lowenuf New Member

    Just went through the same issue. Herm wouldnt admit it, but the machining tolerance of the square washer is garbage. His son finally sent us a used Warn washer, and no more popping out of direct drive...
     
  17. scott milliner

    scott milliner Master Fabricator

    Overdrive has been working fine. I did notice that Herms shifter rod (Bent plate) for the SM465 isn't strong enough. I had to weld a second plate to it. Now it is a 1/4" thick instead of 1/8".