Jeep Wrangler Forum banner
  • Hey everyone! Enter your ride HERE to be a part of JUNE's Ride of the Month Challenge!

1 - 20 of 20 Posts

·
Registered
Joined
·
334 Posts
Discussion Starter · #1 ·
I recently bought a 2012 Sahara Unlimited a little over a week ago. It's lifted with 35" tires. I expected lower than advertised MPG, however I have dipping around 11mpg city. I started noticing the Jeep not going to 5th gear so decided to try to shift manually. It goes 1-4 no problem, when I bump it over to 5th it returns to D on the cluster. Did these early 2012 come with a 4 speed by chance or did someone potentially swap a 4speed auto into it?

When I get underneath the Jeep later, where would I look at the transmission to be stamped to see what transmission it is? I decoded the VIN and it comes back as 5 speed automatic (Rubicon) which confuses me as well.

Any help is appreciated.
Thank you
 

·
Premium Member
Joined
·
2,657 Posts
2012 either had a 5 speed auto or 6 speed manual.

"All-new for 2012 is the 3.6-liter Pentastar V-6 which produces 285 hp and 260 lb-ft of torque. Also new this year is an optional five-speed automatic transmission, replacing the old four-speed unit. A six-speed manual transmission remains standard on all Wranglers."
 

·
Premium Member
Joined
·
2,475 Posts
Did it ever go into 5th? How many miles? When’s the last time the transmission was serviced? What gears are you running?
 

·
Registered
Joined
·
3,315 Posts
If you hold the shifter to the right, it will always switch into D from any manual gear, so make sure you're just bumping it and not holding it. They may not have reprogrammed the Jeep to match the tires.
 

·
Registered
Joined
·
334 Posts
Discussion Starter · #5 ·
Did it ever go into 5th? How many miles? When’s the last time the transmission was serviced? What gears are you running?
It did not go to 5th, RPMs stayed the same. Has 90k miles and I am not certain of the last service as I just got it. I have not had a chance to figure out the gears. I was trying to get it into 5th and hit 70 to get a decent idea of the gears before getting it in the air. As far as I am aware it is stock gears.

If you hold the shifter to the right, it will always switch into D from any manual gear, so make sure you're just bumping it and not holding it. They may not have reprogrammed the Jeep to match the tires.
Was aware of the holding it to the right, so I made sure a few other times to just bump it and still back to D.

I can guarantee it isn't programmed to match the tires as the speedometer is off. Would this inhibit manually shifting into 5th? I am going to call the dealer today to see about programming it.
 

·
Super Moderator
Joined
·
23,754 Posts
it is my understanding that the 2012's show D instead of 5th when using the manual mode. I may be wrong but I remember reading that.
 
  • Like
Reactions: jdinny and Bobnh

·
Registered
Joined
·
334 Posts
Discussion Starter · #8 ·
My dealer cannot program 35s but has hyper tech programmers on hand to purchase. I’ll be grabbing one of these today.
 

·
Registered
Joined
·
6 Posts
What? I thought dealers were responsible to "fix" the Jeeps they took in on trade before reselling them, unless you purchased it "as is". I would insist on them "fixing" the programing "for free" to match what was sold or replacing the 35" tires with a set of OEM tires on original OEM rims (that way you could work the cost of a re-programer for "free", should be cheaper than replacing the tires & rims with OEM's). Now, if the previous owner didn't re-program, they more than likely didn't re-gear either. You can use the vin # to find out what was the original gearing as well or at least pull the original window sticker from Jeep's web site, which should tell you what the gearing was.


Good luck and remember the ":censored:in the dealership show room gets the grease"!
 

·
Registered
Joined
·
334 Posts
Discussion Starter · #10 ·
What? I thought dealers were responsible to "fix" the Jeeps they took in on trade before reselling them, unless you purchased it "as is". I would insist on them "fixing" the programing "for free" to match what was sold or replacing the 35" tires with a set of OEM tires on original OEM rims (that way you could work the cost of a re-programer for "free", should be cheaper than replacing the tires & rims with OEM's). Now, if the previous owner didn't re-program, they more than likely didn't re-gear either. You can use the vin # to find out what was the original gearing as well or at least pull the original window sticker from Jeep's web site, which should tell you what the gearing was.


Good luck and remember the ":censored:in the dealership show room gets the grease"!
I didn't buy it from my local Jeep dealer, I bought it from another dealership so they wouldn't have had the capability/knowledge to program it. I will buy the Hypertech today from the dealer.

Are they able to pull the information on the stock gears? I believe they were 3.21?
 

·
Registered
Joined
·
6 Posts
Still, a dealership needs to make sure the vehicle was safe and inspected (if your state has inspection, which it was not if the speedometer and transmission did not function as designed). The dealer should have shipped it off to a Jeep dealer for the work before reselling it.



If you register the Jeep's VIN with Jeep.com as the owner, you should be able to pull down all the information that Jeep has (dealer service, window sticker, recalls, etc.). If you find an "active or open recall" that is a "BIG FINE" for the dealer, regardless of what brand(s) they sell under.


If the dealer has something like a thirty (30) day return policy, I would make use of it. You paid for a safe vehicle and did not get one!
 

·
Registered
Joined
·
334 Posts
Discussion Starter · #13 ·
Still, a dealership needs to make sure the vehicle was safe and inspected (if your state has inspection, which it was not if the speedometer and transmission did not function as designed). The dealer should have shipped it off to a Jeep dealer for the work before reselling it.



If you register the Jeep's VIN with Jeep.com as the owner, you should be able to pull down all the information that Jeep has (dealer service, window sticker, recalls, etc.). If you find an "active or open recall" that is a "BIG FINE" for the dealer, regardless of what brand(s) they sell under.


If the dealer has something like a thirty (30) day return policy, I would make use of it. You paid for a safe vehicle and did not get one!
We don't have any inspections in Indiana for safety or smog. It was checked for recalls and they have been performed. Just because the speedometer is off doesn't make it an unsafe vehicle.

I will run the VIN and register it on Jeep.com as I did not know that was a thing. Thank you for that.
 

·
Super Moderator
Joined
·
23,754 Posts
again I am pretty sure on a 2012 if you are in manual mode and in 4th (displays a 4) and bump it over it displays a D not a 5. As far as the tranny decoding to a rubicon all models have the same automatic transmission whether a sport, sahara or Rubicon for a given year.
 
  • Like
Reactions: jdinny and Bobnh

·
Registered
Joined
·
334 Posts
Discussion Starter · #15 ·
again I am pretty sure on a 2012 if you are in manual mode and in 4th (displays a 4) and bump it over it displays a D not a 5. As far as the tranny decoding to a rubicon all models have the same automatic transmission whether a sport, sahara or Rubicon for a given year.
Thank you, this is what I was hoping for. Grabbing a programmer today.
 

·
Registered
Joined
·
1,846 Posts
again I am pretty sure on a 2012 if you are in manual mode and in 4th (displays a 4) and bump it over it displays a D not a 5. As far as the tranny decoding to a rubicon all models have the same automatic transmission whether a sport, sahara or Rubicon for a given year.

Pretty sure that is how my 2012 acts. Don't think i have ever seen the cluster show "5".
 

·
Registered
Joined
·
615 Posts
Use Jscan to reprogram your tire size. much less expensive and more versatile than any of the others mentioned.

http://jscan.net/
 
  • Like
Reactions: IceColeNH

·
Registered
Joined
·
3,204 Posts
it is my understanding that the 2012's show D instead of 5th when using the manual mode. I may be wrong but I remember reading that.
again I am pretty sure on a 2012 if you are in manual mode and in 4th (displays a 4) and bump it over it displays a D not a 5. As far as the tranny decoding to a rubicon all models have the same automatic transmission whether a sport, sahara or Rubicon for a given year.
This is correct!!!
Does not show 5th, goes from 4 to D
 

·
Premium Member
Joined
·
8,358 Posts
It should be easy to see if it is shifting even if the diff ratio or tires are not properly set. When you move for 4 to 5 (or D), you should see an RPM drop.
 

·
Registered
Joined
·
334 Posts
Discussion Starter · #20 ·
Thanks everyone, I was able to confirm for sure tonight that once I hit 72mph it will in fact shift to 5th. Bumping it up when manually doing it in 4th does not put it to 5th, though. It’s odd, but I’ve got a programmer coming Monday as the one local was for a JL.
 
1 - 20 of 20 Posts
Top