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Does your automatic lug your motor?

4K views 41 replies 24 participants last post by  Ajaxxx 
#1 ·
I wish I had stuck with my gut instinct and bought a manual. I have a fairly stock 2012 JK with 33’s and 3.73’s. I’m running slightly larger tires than stock but 33’s and 3.73’s aren’t too bad. However, I always feel like the transmission is in a gear higher than it should be, or doesn’t downshift when it should, it’ll just hold the taller gear and lug the motor up a hill, and I either have to push the gas nearly to the floor at which point, it downshifts, the vehicle surges forward, and then I have to let up and then it’ll just upshift again and lug, or I have to manually downshift. Very annoying. The problem is not unique to my JK. I have a 2014 WK2 now which drives fine, but before that I had a 2010 WK and it would do the same thing, the transmission would just lug the motor.

Other than shifting manually all the time, what is the solution to this? It’s very frustrating. I guess I could regear but I don’t think this is an issue with the 33’s since I have experienced it both on my JK and my WK. The power is there, the transmission just always seems to hold at a gear too tall.

Your thoughts are welcome and appreciated.
 
#2 ·
Just tap the stick to the left when you think it should downshift, and to the right when you think it should return to the higher gear.

Even though they call it an automatic, it has a control lever so you can make it do what you want.
 
#7 ·
This is what I'm doing, I'm just curious as to why I have to do it, the automatic should be "smarter" than it is. Climbing steep hills in 4th gear and the engine is lugging at 1200 rpm? Come on, shouldn't it know to downshift on its own? I know I can tap the lever, but I feel like I shouldn't have to...
 
#8 ·
Did you have the upsized tires programmed in to correct the speedo and shift points? Even the small increase can make a difference in the situation you're describing.
Good point, but I already thought of this. My 2010 WK was bone stock and still suffered from the same thing. When I drove my 2012 JK stock, it did the same thing, putting 33's on has merely amplified the problem, but the problem was always there. I know the power is adequate, the car just tends to hold a taller gear than is practical at any given time.
 
#11 ·
My jeep is the same way. Brutal shift points. Hold gears for ever I need to let off has for it to switch gears.

2010 with 33's and 3:73 gears. Going uphill I need to floor it. And merging on the highway is brutal. I should regear and do the pro cal but no money
 
#14 ·
My jeep is the same way. Brutal shift points. Hold gears for ever I need to let off has for it to switch gears.

2010 with 33's and 3:73 gears. Going uphill I need to floor it. And merging on the highway is brutal. I should regear and do the pro cal but no money
Not the same.

Mine is 012 jkr auto 4:1 35"s. Even with procal the trans and motor if left in Drive will try to keep the rpms low IF you are not on the right foot. BUT you need recalibrate the tires size.

I can be doing 45-50mph and it will still go to 5th and rpms can be in the 1200rpm range. Its trying to save you on fuel. IF we could reprogram the shift points it would be better to have the trans extend all shift points a bit as the tires get bigger/jeep gets heavier and move that low point up. But no one I have heard of can crack the trans to motor module at least not enough to even be able to program a 4speed atlas wont work in all 012+ W580autos.

with 35"s up steep grades mine shifts early if left in cruise control it shifts much sooner than if I am at the pedal, never an issue with that and 35"s going up hills . But 1-4 if you are light on the gas it will attempt to shift much to soon even with the two step gears that the w580 has.
 
#12 ·
I'm still rolling stock, but I've never had a lugging problem. This auto has actually been the most precise on gear selection I've ever owned.
 
#13 ·
Thanks everyone for your feedback. The general feeling seems to be that these automatics are all across the board. Some say it's the best shifting transmission ever and some seem to deal with the same issues I'm having. When it's in the proper gear, the Jeep feels great with plenty of power. However, for whatever reason, my transmission seems hell bent on a mission to not let my motor rev above 1500 rpm. I'll have to look into the ProCal, or maybe I'll just regear it in anticipation of 35's anyway. I just hate to do that because it's not a lack of power, it's the stupid transmission always holding a taller gear than it should.

Frustrating, but good to know that I'm not alone in this. Thanks again everyone.
 
#15 ·
2013 JKU running 35s with 3.73 and reprogrammed with a Procal, no lugging. ATs holding a gear and having to fluctuate the skinny pedal to control shifting is something I've been used to and doing since my first car, a 442. So I could be doing without conscious thought. older trans were more likely to kick down, new ones seem more likely to hold higher gears.
 
#17 ·
My 2012 doesn't seem to have this problem.

Your description really does sound like an issue with the ECU still thinking you have smaller tires.
I hope this is the case, the reason I have my doubts is because my 2010 WK lugged as well. My fear is that this is the new reality where manufacturers have to wring every bit of efficiency out of every drop of gasoline to the point where they have programmed transmissions to upshift as soon as possible.

I shoulda boughta manual. :mad:
 
#18 ·
Something to think about... My daughter has an 09 JK which was a dealer demo and actually only driven by the dealerships family members. At some point the transmission was reprogrammed by some knowledgable tech because this JK shifts like no other JK whether 3.8 or 3.6 that I have driven. Un programmed with 35" tires this JK shifts like all JKs should. The slightest touch of the throttle downshifts and it holds gear until the right speed and rpm to maintain momentum.
The downside, this 2 door that shifts so perfectly is harder on gas then my JKU with the same tires.
 
#19 ·
My 2013 Jku all stock with 3.21 gears does the same thing I think its the way it programmed with this Eco crap now . I was playing around with the dash and it looked like you could turn the Eco off or maybe it meant just the Eco that shows on the gauge cluster but I haven't tried it . I wanted to lift mine with 33s but I don't like the way it feels with stock tires so I might hold out until I can swap gears and just go with 35s idk

Sent from my iPhone using JeepForum
 
#25 ·
The ECO display on the dash doesn't actually do anything...its just tells you if you're driving in a relatively fuel efficient manner. Basically a skinny-pedal monitor.
 
#22 ·
I know you said you feel you shouldn't have to, (tap the shifter), but don't let that keep you from managing the transmission as you see fit. It's why the tap shift was programmed into it.

I do it with my 3.8/42RLE, and it's fine. You are way ahead with the engine/transmission in your JK.
 
#21 ·
I have a 2012 JKUS and when I had my RK 2.5" Max Travel Pro lift installed w/ 35x12.5x17R tires, "I also re-geared to 4:88 under the instruction of my mechanic", it drives a lot better than w/stock 3:73 gears and the stock tires from before. If you go up in tire size and do not re-gear or at least program for tire size, the auto trans bogging down is usually what happens.
I love my 12 JKUS with the 4:88 gears & 35's. I know it may be a little over geared but going to get some axle work & 37's when my 35's are done. I can't wait to go to NC for vacation in the mountains in October.
 
#23 ·
I fought this on two TJs with the 42rle auto,hated it.Thats why I bought the 2013 with the 6 sp. Man.That being said I didnt know much about the new 5 sp. autos.But what Ive read they are geared prefectly and kind of thought I should of went that route.So I dont know,but if you regear it will most likely shift at the same rpms.So,it will just shift faster and have a higher freeway rpm.This was my experience with my TJ autos.regeared them both 4.56 and 4.88 with33s.(2004 and 2006).I really like the 6sp. man. I have now,just hope it gives me good service over the long hall.
 
#24 ·
Butterjeep said:
I'd gladly pay more in gas to have my Jeep be more driveable.
If it's worth 14mpg highway to you, as it is us, cool. But unfortunately most anyone getting 14mpg with a 2dr would be livid. Especially when you can get 18 with a JKU on the same tires.

The alternative is to manually shift or what I find works to wake up the computer is just take it out on the freeway once in awhile and hammer it, blow some of that carbon out and relearn the computer. The throttle by wire also plays a part in the shift up/down scenario. Learn to throttle up in a steady motion and not letting up too soon as to have it kick into the next gear too soon.
We run our JKs with factory gears and OD off all the time maintaining constant 2100-2300rpm on the highway which seems to keep the engine happy. I attribute this to the fact that we don't find our JKs to be underpowered with 35s until I try and pull a trailer uphill.
My goal this fall will be to download the advanced transmission shift programming ability for the Superchips and see if I can figure out how to optimize up/down shift patterns.
 
#28 ·
Three letters: EPA

The computer is probably trying to keep your RPM's low to get better gas mileage (I know it's a Jeep, but....).
 
#29 ·
Came home, unpacked my ProCal and the install was a snap. I had already read the directions online and pre-measured my tires. Took the JK for a spin and it's better. I still feel like the transmission is lugging the motor but not as bad. This is about how it felt stock. I guess I am happy. I may experiment and program a tire that's larger to trick the computer into thinking it has taller tires which may encourage it to hold a gear a bit longer before upshifting. The only downside I can think of is that it will cause my speedometer to be slightly optimistic and register that I have slightly more miles than I actually do on the odometer but I feel that would be worth it.

I do agree that Jeep programmed the transmissions to kinda shift early in the name of gas mileage. My WK was really bad. When you're driving up a fairly steep hill and the motor is struggling at 1200 rpm and you have to nearly floor it to get the transmission to downshift, it's enough to make you trade it in for a 2014 WK2! Oh wait, I did do that...

Anyway, I'm not knockin' the ProCal, it's certainly a great product and did what it advertised to do. My issue was more with how the Jeep behaved from the factory. My next one'll be a manual!
 
#31 ·
:cool:--Gearing--Gearing--Gearing-

The ProCal is a great tool, but--

All it does is reprogram the ECU for tirespin vs speedp/odo and slight change in shift points, but--

It won't do anything for eng torque based on final drivetrain Gearing--

Simple fix and it doesn't matter if it's a TJ or JK 3.8l/3.6l--same theory-applies to tire spin vs eng. torque-

:rofl::rofl: JIMBO
 
#32 ·
:agree: Re-Gear! If that and the Pro-Cal doesn't do the trick, Mo' Power helps. I put a RIPP supercharger on mine, and it holds speed just fine, even on the hills. Yes, I re-geared to 5.38s (am on 37's), did the Pro-Cal, and added the supercharger. On long, steep hills, eventually it will downshift, but in the mean time, it holds the RPM's in the power band much longer than it did when non-sc'd.
 
#33 ·
:cool: That's all everso true--

OP, try to remember that when you pay 30k/40k fpr a vehicle--you can't alter all the performance to your satisfactions----for a dime !

Your reason for a JEEP purchase SHOULD be for it's on-road/off-road COMBO attributes and learn to accept deficits in some areas, or-

Be ready to spend X bucks to get what YOU want and that is what a lotta guys do (ME, for one) -

Good luck

:tea: JIMBO
 
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