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2013 JKU Rubi, Baby Lift-Level, Red Leather Seats, Oh La La
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Discussion Starter · #1 ·
I have 112k miles on my Jeep and I don’t think the transmission fluid has ever been flushed. (I bought it at 104k miles of light use — no off roading whatsoever). Lately the transmission (5 speed auto) keeps putting me into limp mode (where I only have 3rd (or is it 2nd??) gear until I stop and restart the vehicle and let it reset). Restarting always fixes it — but I don’t want it doing it period. Obviously.

I’m planning on flushing the transmission fluid next weekend and changing the filter. Service interval for normal driving is 120k miles, so it would make sense that it needs it. Planning to do it at 60k intervals in the future.

Has anybody else had a similar issue with their JK automatic transmission?? Does anybody have tips on flushing the fluid and changing the filter. Looks like I need to take off the exhaust to drop the pan....Jeep 🙄
 

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If you are going into limp get it diagnosed before you do anything. Unless it is low on fluid a flush won't solve your problem. If you need a valve body or internal repair the pan will come off anyway.

The NAG transmission you have is the same as what Hemi cars have used and is pretty sturdy so you probably have a sensor problem. The input and output sensors can fail on occasion and the are part of a wiring harness above the valve body.

Have you considered buying a scanner or a interface for your phone so you can pull trouble codes and see basic data. I don't think you have to pay much and they would be a great thing especially on a trip.

Dropping the pan is easiest if you lower the exhaust. But the header pipe bolts usually break so plan
On replacing them.
 

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I don't know much about the JK transmission but one of our club members's 2016 JKUR trans would not shift properly, got stuck in 2nd, and I think he had limp mode issues too. The dealer would not honor his warranty but this guy called Detroit and somehow got the dealer to rebuild his tranny on Jeeps dime. After a rebuild it still wouldn't work. Then he found out that there are many JK trannies going bad and so many that he was on a long list for a new tranny. Some how he talked to the right people, will say he has connections, and got a new tranny installed and he was able to make the EJS this year and his new tranny did well.

Anyway, I love my Jeeps capabilities, and enjoy Jeep runs with good people but hate the idea that Jeep is more concerned about next years sales than on dependability or honoring warranty promises. Excuse the rant:rolleyes:
 

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Surprised to hear the issues with that particular transmission. It has a good reputation and our JKU has had flawless transmission performance. I will say the 8-speed in the gladiator is even a better performing transmission however.
 
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Transmissions are getting more and more complex - Ford has a 10 speed (my wife's Lincoln Aviator has the 10 speed.)
 

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2013 JKU Rubi, Baby Lift-Level, Red Leather Seats, Oh La La
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55 Posts
Discussion Starter · #6 ·
Transmissions are getting more and more complex - Ford has a 10 speed (my wife's Lincoln Aviator has the 10 speed.)
I used to work at Ford..I was on the manufacturing team that implemented the 10 spd 😜. My fiancé’s F150 has the 10 spd and aside from it being a bit noisy it is stout.
I’m starting to narrow down what my problem might be it seems like when I angrily drive out of the parking lot after work is when it is triggered. So I’m willing to bet it’s a sensor thing as mentioned above....seems that cold powertrain, plus acceleration, plus tight turn = limp mode. At least that’s my working theory at the moment.
 
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