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Discussion Starter #1
I have a brand new 09 Unlimited X 4 door with 2700 miles. This past weekend the transmission popped out of first gear and into neutral when starting from a dead stop - have to immediately shift to second gear. This has happened 3 more times since. It has only happened when starting from a dead stop in first gear and depending on the RPM the popping out can be quite violent - enough to hurt your hand. First time it happened I thought someone had rear ended me. I have it scheduled at the dealer. Searching the web I have found that this seems to be a fairly common problem but I havent found the cure yet. Anyone have any insights?:mad:
 

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FWIW, mine did that a few times when it was brand new. Scared the crap outa me every time. A very loud "BANG!" Now I'm a bit over 40k and it hasn't done it a very long time. Maybe it just needs to break in a bit more?
 

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My first 08 did it in second but my hand was on the shifter and I probably had applied some pressure to it just before getting ready to shift. It was under power and when it happened, the jarring on my hand and the noise really caught me by surprise. Had to check for skid marks :D.

It didn't do it again and it hasn't happened on the Rubi.
 

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Haven't heard of that. We're at about 7k and haven't had that happen. Let us know what the dealer has to say.
 

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I have a 2009 2 Door Sahara that I purchased at the end of March. Around 1500k the transmission began popping out of 3rd gear. It was a pretty violent popping out, much like you guys described. I took it back to the dealer twice and never could get the transmission to do the same thing for them. On the third trip back it finally popped out for a tech that was riding with me. They kept the jeep and ordered new parts for the transmission that they said would "fix" the problem. The parts were on back order so I had to wait a week before they even began to work on it. After the parts were installed they called back to say that the parts did not fix the problem and they were going to put a new transmission in. I waited another week for the transmission to get there. Once it did, they put it in and called to say it was ready. I picked it up and on my way home it popped out of 1st gear!!! I immediately turned around and took it right back. They ordered another transmission and I waited another week. (i had a crappy little dodge caliber for a rental, which they paid for, this whole time...almost a month) Once this last transmission came in and was installed I finally got my Jeep back. I've had no problems since and I'm at 5500k. I hope that's the last of my troubles with my Jeep...I was starting to wonder if I had made a horrible purchase!! So, DEFINITELY take it back to the dealer and demand a new transmission!!
 

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Haven't heard of that. We're at about 7k and haven't had that happen. Let us know what the dealer has to say.
Spoke too soon! At 7,777 miles I experienced the rather violent and very loud pop out of gear from a stop. As jtmdaniels mentioned also, my wife said it seemed like someone rear-ended us. Then again about 10 miles later I experienced a smaller but similar situation when downshifting to 2nd gear.

Very bummed. I'm hoping it was an anomaly and will quietly go away but must admit a bit skeptical.
 

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I responded in another forum to a similar issue as follows:

The 1/2 synchronizer sleeve (in which the 1/2 shift fork rides) moves towards first gear sliding over the synchro hub starting the synchronization process (synchro ring will be indexed and the cone will start picking up the cone of the first gear) Once the speed is equalized the coupler teeth will engage.. These teeth flanks have a back taper to assure positive engagement lock whilst transferring torque..
JOG (jump out of gear) can be created with following main conditions...
1) not enough spline (dogteeth) back-taper on synchro ring and coupler..(Manufacturing quality)
2) not FULL engagement during the shift cycle.. (shifting too fast or shifter boot interference)
3) the first gear has a triple cone synchronizer system and the floating synchro ring might drag too much (particularly in very cold weather..)
4) shift rail detent ball springs too weak (broken or worn out)

Everything has to be in balance to avoid "hard" shifts, (you still want to shift smoothly from 1-2 etc..) on one hand and to avoid JOG on the other hand..

The negative back taper is designed to create a lock whilst torque is transferred, as soon as you coast (reduce torque) the lock becomes less and with a bump it might do a JOG .

Just do a slow shift (be sure it is fully engaged) into first and get moving, keep a constant acceleration and maintain a slight load on the shifter towards second gear.. You will feel the "bite" from the back taper...if something is not right you will detect an easy slide out..

Bring the acceleration to almost coast and try this again..with a slight force the shifter can be moved out of first..

Just trying to give some background music..
 

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Discussion Starter #9
I took it to the dealership 10 days ago and left it for the day. Unfortunately, they were unable to reproduce the problem. It happended again 2 more times this weekend. Needless to say, calling the dealership is one of my first priorities this morning.
 

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I took it to the dealership 10 days ago and left it for the day. Unfortunately, they were unable to reproduce the problem. It happended again 2 more times this weekend. Needless to say, calling the dealership is one of my first priorities this morning.
Just curious, do you have your hand on the shifter when you are accelerating from a stop? My habit is to have my hand on the shifter most all the time, so it's on the shifter when pulling out also, in anticipation of shifting to second.

Not that I should have to but I'm trying real hard keep my hand off the shifter while pulling out and then grabbing it when it's time to shift to second. I've read other places that this seemed to be when it would happen, when the hand is on the shifter.

Either way it's not right but would maybe give a little insight. Read about a few people that had to have the transmission replaced to fix the issue.
 

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Discussion Starter #11
I am quite confident that I have not accidently "pulled" it out of gear. I do tend to keep my hand on the shifter - now moreso in case I have to quickly yank it into second when merging into or crossing traffic to keep from getting in an accident.
 

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My '07 has done this intemittantly since new. But at around 30,000km it started to do it on a regular basis. When i took it to the dealership i also was told thet they could not replicate the problem. But then a couple weeks later i get a phone call saying there is a new transmission waiting to be fitted. Took it in, they fitted the trans, i picked it up, all was fine for about 1-2 weeks. Then it started doing it again, only this time it seems worse than before, and definatly does it more often than before. So back to the dealership, they still couldnt replicate it, so i strapped a video recorder to the center console and filmed it while i was driving. The dealership now has the footage, but have no idea what is going on. They are sending the film to jeep to see what they say.
 

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junk,

Welcome to WF :wavey:.
 

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sounds like there might be a potential recall or something coming up
 

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My '07 has done this intemittantly since new. But at around 30,000km it started to do it on a regular basis. When i took it to the dealership i also was told thet they could not replicate the problem. But then a couple weeks later i get a phone call saying there is a new transmission waiting to be fitted. Took it in, they fitted the trans, i picked it up, all was fine for about 1-2 weeks. Then it started doing it again, only this time it seems worse than before, and definatly does it more often than before. So back to the dealership, they still couldnt replicate it, so i strapped a video recorder to the center console and filmed it while i was driving. The dealership now has the footage, but have no idea what is going on. They are sending the film to jeep to see what they say.

In another forum I posted the following.. (Seen the fact that you got a new tranny, you might dig into this a bit further...)

"Just tell the dealer that you don't have enough positive coupler lock in first gear.. and it needs to be fixed.. I suggest you ask him to take the outer shifter boot off then realign the inner boot assembly over the shifter bracket/sled to which it is installed..I assume that the latter are add on items by the Chrysler assembly plant in their trans dress up line..I am sure this is just a bolt-on process without any positive lock (dowels etc..) My be this needs to be replaced and/or re-aligned..

With a "healthy" set-up you should feel the positive detent engagement whilst shifting in first or any gear..

This was going to be my approach.."


The above mis-alignment can/will affect any gear..

Good Luck..
 

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I responded in another forum to a similar issue as follows:

The 1/2 synchronizer sleeve (in which the 1/2 shift fork rides) moves towards first gear sliding over the synchro hub starting the synchronization process (synchro ring will be indexed and the cone will start picking up the cone of the first gear) Once the speed is equalized the coupler teeth will engage.. These teeth flanks have a back taper to assure positive engagement lock whilst transferring torque..
JOG (jump out of gear) can be created with following main conditions...
1) not enough spline (dogteeth) back-taper on synchro ring and coupler..(Manufacturing quality)
2) not FULL engagement during the shift cycle.. (shifting too fast or shifter boot interference)
3) the first gear has a triple cone synchronizer system and the floating synchro ring might drag too much (particularly in very cold weather..)
4) shift rail detent ball springs too weak (broken or worn out)

Everything has to be in balance to avoid "hard" shifts, (you still want to shift smoothly from 1-2 etc..) on one hand and to avoid JOG on the other hand..

The negative back taper is designed to create a lock whilst torque is transferred, as soon as you coast (reduce torque) the lock becomes less and with a bump it might do a JOG .

Just do a slow shift (be sure it is fully engaged) into first and get moving, keep a constant acceleration and maintain a slight load on the shifter towards second gear.. You will feel the "bite" from the back taper...if something is not right you will detect an easy slide out..

Bring the acceleration to almost coast and try this again..with a slight force the shifter can be moved out of first..

Just trying to give some background music..
WC Engineering : 5th Gear Pop-Out
 

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Glad you are fighting with your dealer...

...I have had this issue from Day 1. I have a 2009 rubicon unlimited, it has been to the dealer and is currently at the deal for this. They are unable to reproduce the problem. It has happened probably 60-100 times (in 7500miles), and they claim that they have never heard of this issue before (bull sh*t).

I did talk to the tranny tech and he let it slip that this is a "common manual transmission problem". Yet the dealer still will not fix the problem because they cannot induce it. I'm writing a letter to corporate, hoping that they will do something. Honestly i either want them to fix it or my money back.

You would expect after paying 30K+ for a automobile it would work right for at least the first year??? Plus this is the 5th issue i've had with mine so until they fix it, i will be negetive nancy. Other than that it is sweet!!!!

sorry for the rant! Please make sure to have the Dealer post the solution on there internal message boards!!!!
 

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I have some serious issues with that "general" overview..Synchro couplers have back tapers to assure positive lock whilst torque is transferred..
My previous reference was typical for the JK manual transmission..
The reference to the helical gear axial forces is correct however the effect on the synchro is minimal as this movement is all included into the design parameters...
 

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The first important job in analyzing a JOG (Jumping Out of Gear) condition is to separate the problem into two main root cause possibilities.. (assuming proper shifting techniques are applied)
1) is it shift lever interference or bad assembly..(external)
2) is it an internal transmission issue....

I am including a pic from their parts catalog to better depict how interferences can be existing between the different boot assemblies (4-5), the shifter sled bracket (8) and its position onto the transmission case..(as referred in above post #16) Any issue here will affect full engagement travel, hence setting you up for a JOG condition..

 
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