JK trans woes

    • 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
      2012 Rubicon - 2.5" AEV Dualsport XT lift, 315/70/17 MTZs, JCR Dagger winch bumper and engine skid, XRC Gen 2 rear bumper, Quadratec LED headlights, ACE side steps, ham radio with GPS tracker
      gone- Long-arm 2001 Cherokee on 35s
    • Stafford wrote:

      What shop? deltrans?
      Local shop, Certified Automotive in Belvedere. They're ordering a reman trans.
      Jerry / Whatevah
      2012 Rubicon - 2.5" AEV Dualsport XT lift, 315/70/17 MTZs, JCR Dagger winch bumper and engine skid, XRC Gen 2 rear bumper, Quadratec LED headlights, ACE side steps, ham radio with GPS tracker
      gone- Long-arm 2001 Cherokee on 35s
    • New

      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.
      The only disability in life is a BAD ATTITUDE!!
      OllllO
    • New

      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