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Syncromesh

Discussion in 'Early CJ5 and CJ6 Tech' started by 3b a runnin, Feb 29, 2016.

  1. 3b a runnin

    3b a runnin Active Member 2023 Sponsor 2022 Sponsor

    I know there has been a lot of discussion here about GL-4 trans oil. I have read all that I can find on this. I can't seem to find any of the specified choices.
    has anybody used Valvoline syncromesh manual trans fluid? it says it is compatible with yellow metals, has phosphorus. here is a link.
    http://content.valvoline.com/pdf/vps_manual_transmission_fluid.pdf
     
  2. BobH

    BobH Member

    This is a good question I would also like to get an answer for. The best I can find is GL4/GL5. No straight GL4.
     
  3. nickmil

    nickmil In mothballs.

    Synthetic. I've had mixed results but frequently poor with customers using synthetic oils in transmissions that were designed to use Dino oil. Don't be surprised if your transmission starts grinding going into gear if you try it.
    Synthetics have their place but these old transmissions are not one of them imho.
     
  4. colojeepguy

    colojeepguy Colorado Springs

    The general concensus seems to be Sta Lube GL4
    Available at NAPA, as well as other places.
     
    dnb71R2 likes this.
  5. Patrick

    Patrick Super Moderator Staff Member

    This is what I run in the T90 in my CJ2A. I order it through Amazon.
     
  6. 47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    Same here. Seems to be the cheapest too. I have wondered about the synchromesh fluid.
     
  7. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    I just finished a T 18 big hole rebuild with a Novak kit and was just looking through past conversations about this subject. Now am scratching by bald head trying to make a choice. Looks like I will use Sta Lube GL4, is that right? I don't remember what I put in the T 90, so I will change all of it to the same thing when I put the new transfercase in next month.
     
  8. nickmil

    nickmil In mothballs.

    Yes, you want the GL-4 specifically. It works the best assuming you aren't in an area with extreme cold.
     
  9. gotime

    gotime Sick with the car bug

    Is the GL-4 what should be used in the axles as well?
     
  10. nickmil

    nickmil In mothballs.

    Less important on the axles. GL-4 or GL-5 works fine in those. If you have a clutch type limited slip don't forget the friction modifier.
     
  11. Twin2

    Twin2 not him 2024 Sponsor 2023 Sponsor 2022 Sponsor

    me too . and buy the pump . it works
     
  12. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    Thanks guys, I just wanted to make sure which way it was, I read the thread about a month ago, but needed to hear it again. I really enjoy this forum, thanks again.
     
  13. garage gnome

    garage gnome ECJ5 welder

    I found this at tractor supply. Its GL1 and is pretty reasonable.

    [​IMG]
     
  14. Danefraz

    Danefraz Well-Known Member 2023 Sponsor 2022 Sponsor

  15. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

  16. Keys5a

    Keys5a Sponsor

    To throw in another gear oil, anyone here using Swepco gear oil? The Porsche racing folks swear by it, and my Vanagon/Subaru crowd recommend one of 4 flavors offered for their overstressed transaxles.
    I haven't tried it yet, but will be using it in the future. I understand it is dino oil as opposed to synthetic.
    -Donny
     
  17. Dave B

    Dave B Frankenjeep '67

    So, what is a good choice for cold-country? I've seen record -58 degrees and the other way to +101 degrees.

    Any recommendation for a T-98 transmission and a D-18 transfer case which would not be unusual to see -20* to +80 degrees.
     
  18. Keys5a

    Keys5a Sponsor

    Your T98 is an old truck transmission from 50 years ago, so don't expect it to shift like a modern gearbox. I would stick with a modern dino-based 85W-90 gear oil. Just expect it to be balky shifting from 30 degrees and colder.
    Modern transmissions use ATF or thinner, but have tighter tolerences. The super thin oil allows shifting in cold climates.
    -Donny
     
  19. nickmil

    nickmil In mothballs.

    Factory Service Manual calls for 80w in winter and 90w in summer, both using GL-4.
    If it shifts too hard in winter when it's reall cold you could use a 50w or 75w GL4 (ep) oil. The temp ranges you are talking about there is no oil for all conditions for these transmissions. Meaning you will be changing it from summer oil to winter oil and back again as temps change.
     
  20. BSweet

    BSweet New Member

    I used Napa brand 80w90 in my axles , trans and transfer case. All seems ok. It seems to shift the same.