NJSAHRA

Ok I know this sounds odd and some will say its in my head but it's not.

My uncle and I both bought our 2012 JKU Saharas at the same time almost identical BOTH AUTO's.

Ok heres what's driving me nuts. I feel like my uncle's JK has a lot more power from 0-30 MPH. When you put any vehicle in Drive and let off the brake you get that slow roll well when I put his in Drive/reverse his rolls fast almost as if his engine had a higher Idle RPM Settting. BOTH Vehicles have the 3.21 I triple checked to make sure his did not have the 3.73's when I noticed the difference.

The only way I could explain this would be to say its like his has 4.10's in it. Where I start to go nuts is both vehicles are IDENTICAL Mechanicly.

Has anyone driven a Friends/Family Pentastar and noticed anything like this or any differences?

Don't get me wrong mine has tons of power an fast for a Wrangler and smooth as can be I just wanna know why the low end difference??

Thanks

P.S. SORRY for the long post!!

ronjenx

What did you do that qualifies as triple checked?

Did you jack up a tire, spin it two revolutions, and count drive shaft turns, on both vehicles?

sq-pa

My friend and I bought '11 JKU Rubi's at the same time, but manuals. I drove a CJ way back in the day and my JK trans kind of shifts the same way my old beast did-hard, jumpy, wanting to stall in 1st if you didn't either punch it or finesse it, and a bit quick, albeit with limited horses (although I'm a torque guy anyway but that's another discussion). I didn't drive my friends identical JK until about a month ago, but he and another friend kept saying that it was a very easy manual to drive, and after driving it his Rubi is much easier and smoother to drive. Mine is not easy-trying to teach my wife to drive a stick has not been easy and I don't blame her. I kinda like the way mine rides because I feel like his rides soft. But for two what-should-be identical Jeeps, they drive way differently. It's about the same RPM's but I haven't spun the tires or anything like that.


I’m bringing mine to the dealer this week just to make sure the trans is ok because I’m putting a lift and bigger tires on in the next couple of weeks and want to make sure my trans isn’t messed up beforehand (ie, get warranty stuff repaired before I perhaps void it…). I’ll let you know. I too almost feel like I have different gears on my Jeep than his. But I don’t want them to soften mine up. I actually want to gear up if 35's are going to spin slow in high gears, but I've gone to sleep at night dreaming that I accidentally got better gears on my rig...

I’ll let you know my findings but I’d be interested to hear opinions.

scouter4life

Let me start with I have the 3.8 and a manual, however I'm guessing the times you've driven his the engine was cold or at least cooled down and your used to driving yours more and most starts from stopped are with a warm engine.

Where I'm going with this is when my engine is cooled off, my RPM's are higher (2000-2500, if I recall correctly) as soon as I let go of the clutch, this is with no accelerator, strictly in gear. At these times I go way faster than after a few minutes when I stop at a light, then let go of the clutch and it barely moves, I have to give it gas and the RPM's are down (900-1200).

My guess is you are experiencing the same thing, but with an Auto, as I would imagine the computer does the same thing. If that is not the case, then my guess would be computer programming may be different for some reason. Though you purchased them about the same time, what are the build dates, that might tell you if they made a change.

sq-pa

Sorry for the delay in reply. First up, thanks for the advice. I actually drove his Jeep from Boston to the Philly area, so I drove it hot, cold, fast, in NY area traffic, etc., and I swear they are two different vehicles, or at least two different models. But like I said, I don't particularly dislike mine: it feels a bit like my old CJ and his feels kinda like my mom's manual Accord I used to drive in high school (ok, not quite that bad...), and I didn't finally buy a Jeep again to have an easy driving car, and I like a little jerk in her. I just want to make my trans/engine/drivetrain is ok before I put a lift on and, if something is not ok now and something comes up after a few mods, the dealer doesn't say it was my fault.

I couldn't bring it in this week because of work, but I'll let you know as soon as I get it in.

Thanks for the advice again.

NJSAHRA

Thanks for the replies!!