JK trans woes

  • Just wanted to share my woes with the group... maybe it'll help someone, maybe not.


    My JK needs a new auto transmission. Was cruising down Limestone Rd the other night and it dropped to second gear and stayed there. Was on my way home to change into work clothes... checked the fluid when I got home and the level was fine, but it was raining and dark so I didn't check the color or smell it. Drove my 3 miles to work and it seemed ok-ish, maybe some torque converter oddities at shifts. Just before I got to work though, dropped back into 2nd gear. Reversed into my parking spot ok, then tried Drive again. Nothing... just revs. Tried reverse again, nothing. Checked on it later during the night and had a P2784 code. Cleared it and took a spin around the parking lot with no issues. On the drive home, lost gears again just before getting home. Parked, and again... no reverse or drive. Check the fluid and it was dark and smelled burnt. I think it had a P0731 code this time.


    Let it sit for a few hours and drove it to a shop. Made it almost a mile before it started acting up, seemed like the torque converter was slipping or shuddering, then only 2nd gear. I was hoping that it just needed a fluid flush, since that always fixed any issue the XJ's AW4 transmission might have. Walked into the shop and after I told them Jeep info, they immediately said it needed a new trans. Apparently it's a recurring problem with these.


    My Jeep info... a 2012 JK Rubicon with the NAG1 / W5A580 trans. 106K miles. It's hard a rough life, 4 cross-country offroad trips, 2 trips pulling a trailer and ~50K miles with 35" tires. And, 2 years as a fire police vehicle with a lot of full-throttle runs... I'm guessing it's mostly the latter responsible for the failure.


    I guess my advice is to check the trans fluid (quality, not level) every time you check the oil and change it more often than the manual recommends. For regular Jeeps, the manual suggests changing the fluid at 120,000 miles, but at 64,000 miles for "police, taxi, fleet, or frequent trailer towing".


    Anyone interested in purchasing a babied 2012 Rubicon with a 2.5" lift and a shiny new transmission? Non-smoker, never offroad. :saint:

    Jerry / Whatevah

    2020 Gladiator Mojave - 33" Falken mud tires, LoD side steps, Zroadz bed rack, Quadratec QRC winch bumper, Superwinch EPi 9.0, Kleinn on-board air, Kleinn air horns, lots of lights, Yaesu ham radio with GPS tracker.

    Gone- 2012 JK Rubicon with stuff. Long gone- Long-arm 2001 Cherokee with stuff.

  • What shop? deltrans?

    Local shop, Certified Automotive in Belvedere. They're ordering a reman trans.

    Jerry / Whatevah

    2020 Gladiator Mojave - 33" Falken mud tires, LoD side steps, Zroadz bed rack, Quadratec QRC winch bumper, Superwinch EPi 9.0, Kleinn on-board air, Kleinn air horns, lots of lights, Yaesu ham radio with GPS tracker.

    Gone- 2012 JK Rubicon with stuff. Long gone- Long-arm 2001 Cherokee with stuff.

  • Certified is a good shop, I've known the Owner Chris for years. He used to work on my personal vehicles and I also had his shop setup to do fleet maintenance on our company vehicles. Due to distance I've started using a shop closer to where I currently live.

  • hmmmm these are the same trans i have been using my SRT for years with tripple the power if not more, i find it hard to believe this thing is smoked as they are rated for 428ft-lbs of input.


    Are you sure its just not the valve body or converter?


    I have upgraded my valve body in a mater of an hour, also changed the trans out in about 3 and been back on the dyno same night lol


    Also i have the special dipstick for checking these transmissions fluid level

  • This sucks. Generally the WA580A is pretty tough. Had the trans on my 2013 go at 50,000 miles. Covered under warranty and there was a TSB for loose/improperly fitting trans dip stick boot/seal that allowed water to slowly get in. Good luck.

  • Got the Jeep back 6 days later. They said there was metal debris floating around in the trans, and I'd be better off with a reman vs rebuilding. One of those things I know absolutely nothing about, so went with their recommendations. They've been fair to me before and to my brother, so I trusted them.


    My JK does definitely get abused. Thinking about it, I've never changed the trans fluid. Oil and coolant, but never the trans... maybe that would have extended the life of it, I dunno.

    Jerry / Whatevah

    2020 Gladiator Mojave - 33" Falken mud tires, LoD side steps, Zroadz bed rack, Quadratec QRC winch bumper, Superwinch EPi 9.0, Kleinn on-board air, Kleinn air horns, lots of lights, Yaesu ham radio with GPS tracker.

    Gone- 2012 JK Rubicon with stuff. Long gone- Long-arm 2001 Cherokee with stuff.

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