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Auto Transmission shifting question
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=1&t=15275		 Page 1 of 1
Author:  07Latitude [ Wed Dec 06, 2006 11:35 am ]
Post subject:  Auto Transmission shifting question
Just an oddball question regarding my 07 Liberty. I've only got 500 miles on it so far, but I've found the transmission likes to go into high gear (and lock the torque converter) right at 44-45 mph in city driving. With variations in the road, it's constantly hunting between 3rd, 4th, and locked/unlocked torque converter. It's been all easy driving so far (not broken in yet). Is the computer still "learning" it's shifting/operating habits? Our 03 liberty we used to have didn't have this issue (had different shift points, and I believe the 03s had a different computer alltogether).

I'm debating whether to do the following:
A) Take it to the dealer, have them look at it and see if there is an updated computer flash for this issue for the 07
B) Drive it until it's broken in, reset the computer, and drive it with a range of easy and hard driving to try to alter shift points a little higher (more performance)
C) Reset the computer now and see if it helps

Anybody here with an 07 (anyone? bueller? :lol:) that has this issue? Or any 06ers (don't know if anything computer-related or engine-related changed; I've heard about electronic throttle control vs. a cable, that true for 07?)
Author:  wendell [ Wed Dec 06, 2006 11:50 am ]
Post subject: 
I would take it to the dealer, I bought my 06 new in the fall and has allways shifed flawlessly. Actually, it's one of the best sifting automatics that I've driven in a long time. I have the 4-speed auto, I can't speak for the 5-spedd auto, if thats what you have.
Author:  07Latitude [ Wed Dec 06, 2006 11:56 am ]
Post subject: 
Yeah, I may do that then and ask. I've made friends w/the local dealer's service manager and operations manager due to problems on another Jeep we own, so I know they'll take care of me. I just wondered if this problem might eventually go away.

The shift cable wasn't attached properly underneath the vehicle when I bought it (park was park, reverse was reverse, neutral was reverse, drive was neutral or drive, 2 was 2, 1 was 2, etc). Took them 10 mins to re-clip or re-attach the cable and then it's been great. They said the cable and the sleeve around it were both moving, instead of just the cable, preventing positive movement of the cable and stops on the shifter. Although the trans does occasionally lightly slip once, maybe twice total on very cold morning first-start upshifts, I figured it was just the vehicle breaking in. I also read that these transmissions like to warm up first before operating.

I'd ordinarily check the trans fluid, but 07s got a "for dealer use only" cap on the trans filler tube instead of a dipstick :roll:

I'll have them scope it in the next week when I get some free time.
Author:  detroit_doc [ Wed Dec 06, 2006 12:04 pm ]
Post subject: 
I read somewhere that a misadjusted shift cable will cause gear hunting on a liberty. If they drive it with a scan tool attached they can see if the PCM is reading the gear position incorrectly while the hunting is occuring.
Author:  Jeepjeepster [ Wed Dec 06, 2006 4:59 pm ]
Post subject: 
There is nothing wrong with it. There has been a few threads on this.. Push the little button on the side of the gear shift to fix it. :wink:
Author:  07Latitude [ Wed Dec 06, 2006 5:05 pm ]
Post subject: 
Jeepjeepster wrote:
There is nothing wrong with it. There has been a few threads on this.. Push the little button on the side of the gear shift to fix it. :wink:


Yeah OD off does help significantly. I was just curious as our 03 never had this problem (and it had the same trans).
Author:  Jeepjeepster [ Wed Dec 06, 2006 5:24 pm ]
Post subject: 
The tranny in your 07 is alittle different.. Its the 42 VLP tranny and you had the 42rle in your 03.. It is alittle odd that your 03 didnt do it? My 04 does it for sure.. Maybe its where your tranny is new? :?

Mine only does it if im REALLY easy on the gas. Like, under 2k rpms.. If i keep it over 2.5krpms, it seems to shift just fine.. :wink:
Author:  07Latitude [ Wed Dec 06, 2006 6:04 pm ]
Post subject: 
Jeepjeepster wrote:
The tranny in your 07 is alittle different.. Its the 42 VLP tranny and you had the 42rle in your 03.. It is alittle odd that your 03 didnt do it? My 04 does it for sure.. Maybe its where your tranny is new? :?

Mine only does it if im REALLY easy on the gas. Like, under 2k rpms.. If i keep it over 2.5krpms, it seems to shift just fine.. :wink:


Window sticker says it's a VLP 42RLE transmission...dont know what VLP stands for but it's still the same overall transmission as the 03 had, at least by name....

Edit: VLP = Variable Line Pressure? Just a wild guess...
Author:  07Latitude [ Wed Dec 06, 2006 6:06 pm ]
Post subject: 
I should also note that it does only seem to really do it at low crusing rpms (smooth 45 mph driving). I've done a couple light WOT runs and it shifts nice and firm (more firm than the 03 ever did actually).
Author:  detroit_doc [ Wed Dec 06, 2006 6:08 pm ]
Post subject: 
Jeepjeepster wrote:
There is nothing wrong with it. There has been a few threads on this.. Push the little button on the side of the gear shift to fix it. :wink:


How can you say that without having seen it? If his new liberty is "hunting" significantly more than his old liberty then it could potentially be a problem. Especially since he has already had a problem with the shift cable once. When I drive 50 MPH over relatively flat ground it stays in overdrive with the torque convertor locked. It will never unlock the convertor or shift out of OD. Only when I hit a hill and start dipping into the throttle will it unlock the convertor. Once my TPS angle reaches about 50% it will finally kick down to 3rd. It takes a pretty noticable hill (at least to use flat-landers) to get it to drop to 3rd.

07Latitude - Ask if the dealer has an '07 demo that you can drive. See if it behaves the same as yours.
Author:  07Latitude [ Wed Dec 06, 2006 6:12 pm ]
Post subject: 
detroit_doc wrote:
Jeepjeepster wrote:
There is nothing wrong with it. There has been a few threads on this.. Push the little button on the side of the gear shift to fix it. :wink:


How can you say that without having seen it? If his new liberty is "hunting" significantly more than his old liberty then it could potentially be a problem. Especially since he has already had a problem with the shift cable once. When I drive 50 MPH over relatively flat ground it stays in overdrive with the torque convertor locked. It will never unlock the convertor or shift out of OD. Only when I hit a hill and start dipping into the throttle will it unlock the convertor. Once my TPS angle reaches about 50% it will finally kick down to 3rd. It takes a pretty noticable hill (at least to use flat-landers) to get it to drop to 3rd.

07Latitude - Ask if the dealer has an '07 demo that you can drive. See if it behaves the same as yours.


I also notice that when it finally does upshift and lockup, unless the road angle and such slows the vehicle down to below 44ish mph, the vehicle will stay put in high gear w/lockup. On flat terrain, if I push the throttle more, it doesn't tend to kick down or unlock until, I'd probably agree, 50% throttle TPS angle.

We have an 06 Grand Cherokee (4.7/545RFE) and it really short-shifted and would stay in 5th at extremely low speeds. It sorted itself out after a while. Thus my instinct on the learning curve of the Mopar computers and such.

We'll see though, I may still take it in. I need a few things from the dealer and am not that far away from there anyways...so it's no big deal to drop by. Plus I'm in good standing with the service and operations managers so....
Author:  Jeepjeepster [ Wed Dec 06, 2006 6:36 pm ]
Post subject: 
Yup, VLP=Varible line pressure. Its the same tranny though. :wink:
Author:  07Latitude [ Wed Dec 06, 2006 6:37 pm ]
Post subject: 
Jeepjeepster wrote:
Yup, VLP=Varible line pressure. Its the same tranny though. :wink:


Didn't you just say it was different? :? :lol:
Author:  psinsyd [ Wed Dec 06, 2006 7:59 pm ]
Post subject: 
07Latitude wrote:
Jeepjeepster wrote:
Yup, VLP=Varible line pressure. Its the same tranny though. :wink:


Didn't you just say it was different? :? :lol:


How do you think he got so many posts?!?! :lol:

:wink:
Author:  07Latitude [ Wed Dec 06, 2006 8:00 pm ]
Post subject: 
psinsyd wrote:
07Latitude wrote:
Jeepjeepster wrote:
Yup, VLP=Varible line pressure. Its the same tranny though. :wink:


Didn't you just say it was different? :? :lol:


How do you think he got so many posts?!?! :lol:

:wink:


:-)r that's great! haha
Author:  Jeepjeepster [ Wed Dec 06, 2006 9:40 pm ]
Post subject: 
07Latitude wrote:
Jeepjeepster wrote:
Yup, VLP=Varible line pressure. Its the same tranny though. :wink:


Didn't you just say it was different? :? :lol:


I said the tranny was alittle different. its the same tranny, but it has Varible Line pressure.. :)
Author:  07Latitude [ Wed Dec 06, 2006 9:47 pm ]
Post subject: 
Jeepjeepster wrote:
07Latitude wrote:
Jeepjeepster wrote:
Yup, VLP=Varible line pressure. Its the same tranny though. :wink:


Didn't you just say it was different? :? :lol:


I said the tranny was alittle different. its the same tranny, but it has Varible Line pressure.. :)


Ok then. Lol.

Too bad line pressure shouldn't have anything to do with my issue but really alters shift firmness and such. :?

Prob. going to take it in next week sometime and see what the dealer says. I'll also drive my girlfriend's 06 to see what hers does around 45 mph (compare my 07 to an 06 that is fully broken in for a more accurate comparison compared to our old 03).
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