Front Range 4x4 Upcoming Trail Runs - Add a New Trail Run

Results 1 to 20 of 20

Thread: AX15 trouble/questions

  1. #1
    Join Date
    Aug 2018
    Member
    #2201
    Last Online
    1 Day Ago
    Location
    Longmont, CO
    Age
    34
    4x4
    97 TJ
    Posts
    130
    User Name
    rckymtnt4r
    Real Name
    Schmitty
    Thanks Given
    86
    Thanked 41 Times in 32 Posts

    Default AX15 trouble/questions



    Having some intermittent issues with the trans on the TJ: on hot days or after driving it for a while it sometimes won't go into 1st or 2nd gear. I'll have to let the Jeep roll a little or bump into 3rd then over to 1st before it'll go into gear. I'm thinking either a syncro is toast or a dog ring needs replacement.

    One thing to note is that I recently replaced the fluid (which was very dark and dirty) with new MTF.

    I've read that rebuilding an AX-15 is better left for a shop with the proper tools and remanufactured ones cost about $1200 after core deposit. What are y'all's thoughts?

  2. #2
    Join Date
    Sep 2011
    Member
    #921
    Last Online
    7 Hours Ago
    Location
    Fort Collins
    4x4
    1990 Jeep Wrangler (YJ)
    Posts
    8,725
    User Name
    Jim
    Real Name
    Jim Williamson
    Thanks Given
    1,836
    Thanked 2,432 Times in 1,610 Posts

    Default Re: AX15 trouble/questions



    MTF - manual trans fluid?

    As you said you just changed fluid and you're now having issues. I think I'd change fluid one more time (edit: with a different fluid) and see.

    Here's what I have listed for my AX15 5-speed manual trans fluid change info:
    ATF Fluid (any type), 15-25 ft-lbs drain/fill plugs, 1-3/16" socket; Drain & Fill plugs to 20 Ft-Lbs

  3. The Following Member Says Thanks to Jim For This Post:

    rckymtnt4r (August 22nd, 2021)

  4. #3
    Join Date
    Jul 2014
    Member
    #1546
    Last Online
    10 Hours Ago
    Location
    Denver, CO
    Age
    43
    4x4
    1970CJ5-1958WillysWagon-2010Tacoma
    Posts
    3,209
    User Name
    FINOCJ
    Real Name
    James Orofino
    Thanks Given
    1,033
    Thanked 1,298 Times in 780 Posts

    Default Re: AX15 trouble/questions



    rckymtnt4r previously posted:
    "One thing to note is that I recently replaced the fluid (which was very dark and dirty) with new MTF."

    Did you use GL-5? Novak has this to say:
    The factory manuals call for 75W90 GL-3 gear oil for the AX15 transmission. This fluid is essentially obsolete; superseded by GL4, then GL5. However, many GL5 fluids have friction modifiers that are not compatible with synchronizers, so make sure to check for compatibility.

    The old transmission and TCs found in my old jeeps have this issue as well...I found StaLube gear oil from NAPA that is good for the yellow metal synchronizers and blocking rings seems to work really well....
    ___________
    James Orofino
    1970 CJ5
    1958 Willys Wagon
    2010 Tacoma TRD

  5. The Following 2 Members Say Thanks to FINOCJ For This Post:

    Jim (August 20th, 2021),rckymtnt4r (August 22nd, 2021)

  6. #4
    Join Date
    Sep 2014
    Member
    #1596
    Last Online
    7 Hours Ago
    Location
    Timnath
    4x4
    2012 Rock Ware Buggy & 2007 JKUR
    Posts
    1,444
    User Name
    newracer
    Real Name
    Michael
    Thanks Given
    151
    Thanked 609 Times in 371 Posts

    Default Re: AX15 trouble/questions



    I ran Redline MT-90 in mine, smoothed out the little crunching in 2nd I was having.

  7. The Following 3 Members Say Thanks to newracer For This Post:

    Jim (August 20th, 2021),rckymtnt4r (August 22nd, 2021),Steve-O (August 22nd, 2021)

  8. #5
    Join Date
    Jun 2011
    Member
    #853
    Last Online
    6 Days Ago
    Location
    Denver
    4x4
    LJ, Xterra
    Posts
    6,827
    User Name
    Paul
    Real Name
    Paul
    Thanks Given
    1,856
    Thanked 1,564 Times in 1,089 Posts

    Default Re: AX15 trouble/questions



    https://www.novak-adapt.com/knowledg...ns/manual/ax15

    They say 50w, I personally use 10w-30 Mobil 1 in everything from the engine to the axles.

  9. The Following 2 Members Say Thanks to Paul For This Post:

    Jim (August 21st, 2021),rckymtnt4r (August 22nd, 2021)

  10. #6
    Join Date
    Aug 2015
    Member
    #1761
    Last Online
    11 Hours Ago
    Location
    Englewood Co.
    Age
    61
    4x4
    91 Jeep Cherokee
    Posts
    1,186
    User Name
    JandDGreens
    Real Name
    David
    Thanks Given
    232
    Thanked 392 Times in 244 Posts

    Default Re: AX15 trouble/questions



    FINOCJ previously posted:
    "Did you use GL-5? Novak has this to say:
    The factory manuals call for 75W90 GL-3 gear oil for the AX15 transmission. This fluid is essentially obsolete; superseded by GL4, then GL5. However, many GL5 fluids have friction modifiers that are not compatible with synchronizers, so make sure to check for compatibility.

    The old transmission and TCs found in my old jeeps have this issue as well...I found StaLube gear oil from NAPA that is good for the yellow metal synchronizers and blocking rings seems to work really well...."

    What he said. I made the mistake of changing my oil. Did not know that I needed to use a specific oil. Once I bought the correct oil (Redline MT-90 not cheap!) and changed it out it was all good. I was lucky that there wasn't too much damage to the synchro's. It's been good for 4 years now.

  11. The Following Member Says Thanks to JandDGreens For This Post:

    rckymtnt4r (August 22nd, 2021)

  12. #7
    Join Date
    Jul 2020
    Member
    #2744
    Last Online
    14 Hours Ago
    Location
    Denver
    4x4
    1993 Jeep YJ (stock)
    Posts
    221
    User Name
    Steve-O
    Real Name
    Steven
    Thanks Given
    187
    Thanked 106 Times in 62 Posts

    Default Re: AX15 trouble/questions



    MT-90 in my AX-5. Good stuff!
    ___________
    Steven
    2004 Wrangler Rubicon
    1993 Wrangler S
    2015 Cherokee

  13. The Following Member Says Thanks to Steve-O For This Post:

    rckymtnt4r (August 22nd, 2021)

  14. #8
    Join Date
    Aug 2018
    Member
    #2201
    Last Online
    1 Day Ago
    Location
    Longmont, CO
    Age
    34
    4x4
    97 TJ
    Posts
    130
    User Name
    rckymtnt4r
    Real Name
    Schmitty
    Thanks Given
    86
    Thanked 41 Times in 32 Posts

    Default Re: AX15 trouble/questions



    FINOCJ previously posted:
    "The factory manuals call for 75W90 GL-3"

    That was my reference... hmm foiled for being a nerd. drats!

    I'll try what Jim suggested before investing in Redline. The best oil is clean oil.

    Thanks for all the feedback, I'll change the fluid and relay my findings.

  15. #9
    Join Date
    Sep 2011
    Member
    #921
    Last Online
    7 Hours Ago
    Location
    Fort Collins
    4x4
    1990 Jeep Wrangler (YJ)
    Posts
    8,725
    User Name
    Jim
    Real Name
    Jim Williamson
    Thanks Given
    1,836
    Thanked 2,432 Times in 1,610 Posts

    Default Re: AX15 trouble/questions



    rckymtnt4r previously posted:
    "I'll change the fluid and relay my findings."


  16. #10
    Join Date
    May 2019
    Member
    #2609
    Last Online
    4 Days Ago
    Location
    Littleton, CO
    4x4
    Jeep TJ, Nissan Xterra, Ford E350
    Posts
    158
    User Name
    Trevor?
    Real Name
    Trevor
    Thanks Given
    30
    Thanked 93 Times in 61 Posts

    Default Re: AX15 trouble/questions



    I have no idea what was in my AX-15 when I bought it, but it did have a hard time with 1-2 shifts until I drove it a few miles and it warmed up. I tried 10w-30 after Paul mentioned it and it does shift much better now. It does seem odd, but it appears a lot of folks out there use it.

    It took a few weeks before I started to notice an improvement. I suppose there's a chance it may revert to it's old ways once it starts to get cold again, but so far so good.

    Edit: It may help to elaborate: I would get a little clash shifting from 1 to 2.... it felt as if the syncro wasn't generating enough friction to bring the intermediate shaft to speed. Your issue sounds a bit different maybe.

  17. #11
    Join Date
    Sep 2011
    Member
    #921
    Last Online
    7 Hours Ago
    Location
    Fort Collins
    4x4
    1990 Jeep Wrangler (YJ)
    Posts
    8,725
    User Name
    Jim
    Real Name
    Jim Williamson
    Thanks Given
    1,836
    Thanked 2,432 Times in 1,610 Posts

    Default Re: AX15 trouble/questions



    This might be a good spot to show the WAY EASY method I use to fill my AX-15...

    (I do have a 3" body lift but those with standard body lift should be OK with this)

    www.JimWilliamson.net/automobile/2017-09-02--tech--ax15-fill-through-body-drain-hole/

  18. The Following 5 Members Say Thanks to Jim For This Post:

    JandDGreens (August 23rd, 2021),rckymtnt4r (August 23rd, 2021),Steve-O (August 24th, 2021),Tom (August 23rd, 2021),Trevor? (August 23rd, 2021)

  19. #12
    Join Date
    May 2019
    Member
    #2618
    Last Online
    7 Hours Ago
    Location
    Nederland, CO
    Age
    44
    4x4
    2006 Range Rover and 2011 G-Wagen
    Posts
    794
    User Name
    speedkills
    Real Name
    Shane
    Thanks Given
    405
    Thanked 326 Times in 197 Posts

    Default Re: AX15 trouble/questions



    Thatís a pretty great trick.

  20. #13
    Join Date
    Aug 2018
    Member
    #2201
    Last Online
    1 Day Ago
    Location
    Longmont, CO
    Age
    34
    4x4
    97 TJ
    Posts
    130
    User Name
    rckymtnt4r
    Real Name
    Schmitty
    Thanks Given
    86
    Thanked 41 Times in 32 Posts

    Default Re: AX15 trouble/questions



    Jim previously posted:
    "This might be a good spot to show the WAY EASY method I use to fill my AX-15..."

    Clever...

  21. #14
    Join Date
    Aug 2018
    Member
    #2201
    Last Online
    1 Day Ago
    Location
    Longmont, CO
    Age
    34
    4x4
    97 TJ
    Posts
    130
    User Name
    rckymtnt4r
    Real Name
    Schmitty
    Thanks Given
    86
    Thanked 41 Times in 32 Posts

    Default Re: AX15 trouble/questions



    Alright I ran a fresh fill of some ATF for a week, still same problem. Drained and refilled with 10w-30 Castrol conventional oil; It shifts into 1st easier and all other shifts are smoother.

  22. #15
    Join Date
    Jun 2011
    Member
    #853
    Last Online
    6 Days Ago
    Location
    Denver
    4x4
    LJ, Xterra
    Posts
    6,827
    User Name
    Paul
    Real Name
    Paul
    Thanks Given
    1,856
    Thanked 1,564 Times in 1,089 Posts

    Default Re: AX15 trouble/questions



    Someone please correct me if I am wrong, I really don't want to say the wrong thing here, but I don't think conventional oil is OK in an AX-15 due to yellow metal. I think you need to switch to synthetic or your syncros will be damaged.

  23. #16
    Join Date
    Jul 2014
    Member
    #1546
    Last Online
    10 Hours Ago
    Location
    Denver, CO
    Age
    43
    4x4
    1970CJ5-1958WillysWagon-2010Tacoma
    Posts
    3,209
    User Name
    FINOCJ
    Real Name
    James Orofino
    Thanks Given
    1,033
    Thanked 1,298 Times in 780 Posts

    Default Re: AX15 trouble/questions



    rckymtnt4r previously posted:
    "Alright I ran a fresh fill of some ATF for a week,"

    Do you mean you ran Automatic Transmission fluid in it? IIRC the AX-15 is a 5 speed manual....I wouldn't run ATF in a manual trans.
    ___________
    James Orofino
    1970 CJ5
    1958 Willys Wagon
    2010 Tacoma TRD

  24. #17
    Join Date
    Jul 2014
    Member
    #1546
    Last Online
    10 Hours Ago
    Location
    Denver, CO
    Age
    43
    4x4
    1970CJ5-1958WillysWagon-2010Tacoma
    Posts
    3,209
    User Name
    FINOCJ
    Real Name
    James Orofino
    Thanks Given
    1,033
    Thanked 1,298 Times in 780 Posts

    Default Re: AX15 trouble/questions



    Paul previously posted:
    "but I don't think conventional oil is OK in an AX-15 due to yellow metal. I think you need to switch to synthetic or your syncros will be damaged."

    You can definitely run conventional oil in an an old manual with yellow metal - it just can't be the common modern GL-5 rating. There are a number of GL-3 and GL-4 conventional option out there - but rarely at local parts stores (although the Sta-Lube can often be found at NAPA). Another option is to run 10-30 synthetic motor oil like Mobil 1 - but be cautious of synthetic 90W gear oil as it may not do well with yellow metal either (especially if it says hypoid).
    ___________
    James Orofino
    1970 CJ5
    1958 Willys Wagon
    2010 Tacoma TRD

  25. #18
    Join Date
    Aug 2015
    Member
    #1761
    Last Online
    11 Hours Ago
    Location
    Englewood Co.
    Age
    61
    4x4
    91 Jeep Cherokee
    Posts
    1,186
    User Name
    JandDGreens
    Real Name
    David
    Thanks Given
    232
    Thanked 392 Times in 244 Posts

    Default Re: AX15 trouble/questions



    What he said. I made the mistake of changing my oil. Did not know that I needed to use a specific oil. Once I bought the correct oil (Redline MT-90 not cheap!) and changed it out it was all good. I was lucky that there wasn't too much damage to the synchro's. It's been good for 4 years now.

    Cost me aprox $70 but it fixed my issue.

  26. The Following Member Says Thanks to JandDGreens For This Post:

    Tom (3 Weeks Ago)

  27. #19
    Join Date
    May 2019
    Member
    #2609
    Last Online
    4 Days Ago
    Location
    Littleton, CO
    4x4
    Jeep TJ, Nissan Xterra, Ford E350
    Posts
    158
    User Name
    Trevor?
    Real Name
    Trevor
    Thanks Given
    30
    Thanked 93 Times in 61 Posts

    Default Re: AX15 trouble/questions



    I am under the impression that the thing to look out for with yellow metal in transmissions is using a lubricant containing sulfur compounds. Its the sulfur that is not compatible with yellow metals and gL4 and 5 oils may contain sulfur. Aside from that it seems that AX15's can be picky about the exact lubricity of the oil used. I thought this was an interesting discussion on the topic: https://forums.4wdmechanix.com/topic...sion-gear-oil/

    I think if you are getting good shifts with the 10w30 and it doesn't seem like its getting excessively hot then you are probably fine.

  28. #20
    Join Date
    May 2019
    Member
    #2609
    Last Online
    4 Days Ago
    Location
    Littleton, CO
    4x4
    Jeep TJ, Nissan Xterra, Ford E350
    Posts
    158
    User Name
    Trevor?
    Real Name
    Trevor
    Thanks Given
    30
    Thanked 93 Times in 61 Posts

    Default Re: AX15 trouble/questions



    Been doing some more reading. Maybe this is all common knowledge for some, but I found it interesting and I hope others will too.

    A good summary on different lubrication scenarios.
    https://www.machinerylubrication.com...cation-regimes

    Boundary lubrication would describe the high pressure sliding contact in a hypoid differential gearset. EP (Extreme Pressure) gear oils are designed for these applications. I believe engine oils are designed more for applications involving full film lubrication. A manual transmission is probably in-between these two applications. It should involve mostly rolling contact with helical and spur gear-sets and greater and greater pressures with increasing torque.

    "EP gear oils contain additives that prevent metal surfaces from cold welding under the extreme pressure conditions found in situations where boundary lubrication prevails.
    At the high local temperatures associated with metal-to-metal contact, an EP additive combines chemically with the metal to form a surface film that is ductile enough to prevent the welding of opposing asperities and prevent scuffing or scoring that is destructive to sliding surfaces under high loads (Figure 1). Chemically reactive compounds of sulfur, phosphorus and sometimes chlorine, are used to form these inorganic films."
    https://www.machinerylubrication.com...ur-ep-gear-oil

    Reading further it discusses chemical compatibility issues with reactive sulfur compounds and copper.

    API publication with more details on GL raiting designations:
    https://www.api.org/-/media/Files/Ce...April-2013.pdf

    It seems like GL raitings dictate performance critera but not chemical composition, however in order to meet the performance criteria most oil manufactures appear to be using reactive sulfur additives.

    It looks like Redline MT-90 and other products that claim to be safe for syncros and yellow metals are EP oils using a combination of additives with this compatibility issue in mind. There is a Pennzoil product out there too. Also one from Valvoline that appears to be priced a little better. I'm sure there are more.

    https://www.pennzoil.com/en_us/produ...ion-fluid.html
    https://www.valvoline.com/our-produc...ynchromesh-mtf

    I'm getting the feeling that the right choice for anyone is going to be dependent on application. If your jeep isn't particularly heavy and you're not driving aggressively then you're generally generating less torque in the transmission and your gear contact pressures should be lower. The 10W30 path is probably fine.... it does appear to be recommended by Mopar with their substitution of 4761839ad for 4897622aa. If you have a lot of extra weight from modifications, and if you are generating more torque from your engine and drive aggressively than you may stand to benefit from one of these EP oils. There's no clear line in the sand between these two positions.

    I'm starting to think about switching away from 10W30 if I can do so without spending MT-90 prices. That Valvoline fluid is going in the mid $7/qt range and claims to meet GL-4. The question will be if it would still make for good shifts. I may try that the next time I change that fluid.

    Also I dont know why I keep wanting to type sulfur with a ph. Cant shake that for some reason.

  29. The Following 4 Members Say Thanks to Trevor? For This Post:

    FINOCJ (2 Weeks Ago),JandDGreens (2 Weeks Ago),Jim (2 Weeks Ago),speedkills (2 Weeks Ago)

Similar Threads

  1. Jeep Trouble Codes
    By Paul in forum Tech How To
    Replies: 3
    Last Post: June 20th, 2017, 07:15 PM
  2. Having trouble getting into 4L
    By Gorden in forum Tech Help Wanted
    Replies: 20
    Last Post: June 26th, 2013, 06:12 AM
  3. trouble posting
    By Paul in forum Chat
    Replies: 12
    Last Post: September 22nd, 2012, 06:21 PM
  4. Computer trouble
    By Chris in forum Chat
    Replies: 8
    Last Post: March 25th, 2010, 08:34 AM
  5. Trouble Codes
    By Chris in forum General Topics
    Replies: 2
    Last Post: October 27th, 2009, 02:39 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
BACK TO TOP