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Discussion Starter · #1 ·
My jeep feels like it is slipping 2nd gear. When going in a straight line from a stand still or when slowed down and trans shifts down to 2nd it feels like it is slipping before it fully engages in the gear. The only time it doesn't do it is if I'm turning from a stand still. Then it shifts as should but it runs the rpms in 1st fear up to about 26-2800 before shifting. It basically happens anytime the trans shifts and rpms are under 2500. I took it to the dealer and they have reprogrammed with updates twice now to no avail. It was doing it with stock tires also. I have since lifted and regeared to 4.10. Since regearing it isn't quite as bad, but its still doing it. Its like it doesn't have the right line pressure to make the shift happen. Maybe a torque converter issue?

I'm also holding 3rd gear way to long, even on the slightest inclines. I will go to 4,000rpms and never shift. I have to completely let off the gas before it will shift.

I'm about to take it back to the dealer for the 4th time with this issue. Yes my local dealer sucks bad. Any advice anyone can give me? Is there a tsb that I haven't been ae to find through my searches? Jeep has 27k on it. Any wisdom is greatly appreciated.
 

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any check engine lights? does the transmission slip when in manual mode? Have you checked the transmission fluid? (dipstick is under the engine cover to the left near the fire wall)

Maybe get a transmission flush. The NAG1 WA580's are very sensitive to under/over filling.
 

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Discussion Starter · #3 ·
No lights. Trans fluid is at the right level and doesn't smell burned. Yes, I can replicate the slippage using the manual shift. If you shift under 2600ish rpms its going to do it, everytime!

And fyi, I know my way around the engine compartment so throw what you got at me. I'm a weekend gear head. I've got a few 350 builds and a about half rebuilt my power stroke and cummins through the years. Transmissions are their own animals though.
 

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There have been some problems in 2013 and 14 with faulty modulators. There have also been torque converter and valve body issues.
 

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No lights. Trans fluid is at the right level and doesn't smell burned. Yes, I can replicate the slippage using the manual shift. If you shift under 2600ish rpms its going to do it, everytime!

And fyi, I know my way around the engine compartment so throw what you got at me. I'm a weekend gear head. I've got a few 350 builds and a about half rebuilt my power stroke and cummins through the years. Transmissions are their own animals though.
The second part of your complaint can be normal at times, but the trans. will normally shift like that on more extreme inclines. The first part isn't normal. Owners that I know with 12+ JK auto transmissions, and the ones that I have driven, don't normally operate like you mentioned as far as that much slipping when it down shifts. It could be a faulty modulator. Whatever it might be, it should be diagnosed. Some dealers will send it to a private shop if they need a complete diagnosis. I would take it back in.
 

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There have been some problems in 2013 and 14 with faulty modulators. There have also been torque converter and valve body issues.
My 13 has all of this. Double shifts, hooting you name it. So glad I kept the stock wheels. I'm sure if I rolled in on my 35s they wouldn't even hang a ticket on the mirror.
 

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Discussion Starter · #8 ·
There have been some problems in 2013 and 14 with faulty modulators. There have also been torque converter and valve body issues.
I'm thinking this may be the issue. I'm planning to take it back in this week. I'm hoping it can be resolved without me having to get ugly with them. The good thing is, it was doing it prior to me lifting and I took it in and they reprogrammed it which helped a little but didn't resolve the problem. I've got all the paper work.
 

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I have a 2016 with 3.73s that does EXACTLY what you mentioned with the second gear slipping in all conditions except when turning.

Did you ever get this resolved? Solution?

I'm going to take it in and would like to know the posible problem beforehand.
 

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Discussion Starter · #10 ·
Good luck! I've had it at the dealer twice in the last 3 months. The transmission "expert", as they call him, has ridden with me one of the times. I drive and show him the exact symptoms, which are very obvious. He even agreed and says he sees what its doing. They keep it all day and call to tell me its ready. I get there and they say nothing is wrong. Its mind boggling. Actually, its typical dealer crap. There is another dealer in my area. I'm fixing to take it to them and see what they say about it. I've thought about taking it to a couple transmission shops to get their expert opinion on it. Then take that info with me and start talking/looking for some legal advice.

If you get a better answer, let me know. I would love to know what another dealer did to fix the problem.
 

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I have a similar issue with my 2012 JKU Arctic Edition. It has 62K miles on it now and started the issue around 58K miles. I get hard rough shifts either up or down around the 3rd gear range or 35-45 MPH. I have had it serviced numerous times and the Jeep place did replace the torque converter, flushed the transmission, and serviced the transmission. It drives mostly like new now except for that rough shift at the same speed spot. If I find out anything more I will let you know but so far everyone at Jeep is stumped. I have an open case and STAR case with no luck so far.

Regards.
 

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I'll let you know what my dealership says, but it's going to be at least a couple of weeks before I can get it in there.

I've searched high and low and found a few references to similar problems, but I have never seen a resolution. Most people seem to associate it with the torque converter clutch locking up and say it's normal. Maybe it is, but I have a hard time believing that a transmission that goes behind much more powerful engines has to slip so much in second gear in a Jeep.

I have '14 Darango that has the first year 8-speed in it that had lots of issues with the factory tune. I took that in to the same dealership I'm going to take the Jeep to and the foreman was a pretty straight shooter and did an excellent job correcting it. However, many of those problems were well documented at the time and there were TSBs addressing what to do. Regardless, I'm hopeful that he'll be knowledgeable with this one since it's been used in so many applications for quite a while.

I'll report back once I know.
 

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If the trans was slipping, the rpm will go up, but the Jeep woud loose the accel momentum, pay attention to the rpm/mph and see what it does..., i think what you're feeling is the just the torque converter locking, hopefully, it's normal, and happens in 2nd gear.

I wish i can show you what mine does when it locks, as i don't allow my verter to slip when the clutch is engaged (TCM manipulation via tuning), you can really feel when the the locking clutch is applied, (feels almost like shift on its own), is not bad though, and it helps the trans a lot, as the converter literally doesn't slip while the locking clutch is engaged.
 

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Discussion Starter · #14 ·
I'll let you know what my dealership says, but it's going to be at least a couple of weeks before I can get it in there.

I've searched high and low and found a few references to similar problems, but I have never seen a resolution. Most people seem to associate it with the torque converter clutch locking up and say it's normal. Maybe it is, but I have a hard time believing that a transmission that goes behind much more powerful engines has to slip so much in second gear in a Jeep.
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Same issue here with the research and agree about the application with other more powerful vehicles. Its not normal, nor is it suppose to happen. If is a lock out issue then the coverter is bad. With all the diesels I've owned I know what it feels like when a coverter locks out and its nothing like this.

please let us know what you find out!
 

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Here's the short answer: "It's normal." Read on for the longer version.

Although I'm a fairly competent home mechanic, the inner workings of an auto trans and its associated programming are beyond me. I'll convey what the techs told me, but I'm not vouching for whether their info is right or wrong.

I took it in about a week and a half ago and had the shop foreman ride with me so I could show him exactly what it was doing and have him feel the difference between shifts in a straight line and from a stop with the steering wheel turned. He felt and heard the same thing I did but was not concerned at all. His explanation was that the tuning is setup for "eco" shifting and that the engineers have programmed the shift points under normal load to keep the RPM's in the green zone on the tach. That green zone ends right at 2,500 rpm. You noted in your first post that that is where yours shifts from first to second under normal conditions. Mine is the same. When starting with the wheel turned, for some reason the programming allows the RPMs to build more before shifting to second.

What is happening under normal conditions in a straight line is that the gears are shifting quickly but the torque converter % engagement is happening slower and that is why we are perceiving a slipping sensation. It is clearly capable of quicker engagement at higher RPMs, as evidenced by performance off a corner or when standing on it, but it isn't tuned to do that normally. Why that is I'll never understand.

I asked him to check for any programming updates and he was fine with that and he also wanted to drive one off the lot for a comparison. There was one update for the PCM to address miss-fires and general throttle response, but nothing for the TCM. We drove the new one with 50 miles on it and it performed the same way. As much as its programming erks me, it's pretty hard to argue that something's wrong when another brand new vehicle does the same thing.

So, unfortunately, I don't have an answer that will make you more comfortable. I did find some comfort in his explanation that the torque converter "clutch" is not a traditional clutch pack with discs, but rather a variable hydraulic lock between 5% and 95% lockup. So, that slipping that we're feeling is not destroying anything other than the trans fluid. All that tells me is that I have to be sure to be on top of service intervals and use good fluids. I have better than 4 years and 53k miles left in warranty, so I guess time will tell.
 

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Discussion Starter · #16 ·
Here's the short answer: "It's normal." Read on for the longer version.

Although I'm a fairly competent home mechanic, the inner workings of an auto trans and its associated programming are beyond me. I'll convey what the techs told me, but I'm not vouching for whether their info is right or wrong.

I took it in about a week and a half ago and had the shop foreman ride with me so I could show him exactly what it was doing and have him feel the difference between shifts in a straight line and from a stop with the steering wheel turned. He felt and heard the same thing I did but was not concerned at all. His explanation was that the tuning is setup for "eco" shifting and that the engineers have programmed the shift points under normal load to keep the RPM's in the green zone on the tach. That green zone ends right at 2,500 rpm. You noted in your first post that that is where yours shifts from first to second under normal conditions. Mine is the same. When starting with the wheel turned, for some reason the programming allows the RPMs to build more before shifting to second.

What is happening under normal conditions in a straight line is that the gears are shifting quickly but the torque converter % engagement is happening slower and that is why we are perceiving a slipping sensation. It is clearly capable of quicker engagement at higher RPMs, as evidenced by performance off a corner or when standing on it, but it isn't tuned to do that normally. Why that is I'll never understand.

I asked him to check for any programming updates and he was fine with that and he also wanted to drive one off the lot for a comparison. There was one update for the PCM to address miss-fires and general throttle response, but nothing for the TCM. We drove the new one with 50 miles on it and it performed the same way. As much as its programming erks me, it's pretty hard to argue that something's wrong when another brand new vehicle does the same thing.

So, unfortunately, I don't have an answer that will make you more comfortable. I did find some comfort in his explanation that the torque converter "clutch" is not a traditional clutch pack with discs, but rather a variable hydraulic lock between 5% and 95% lockup. So, that slipping that we're feeling is not destroying anything other than the trans fluid. All that tells me is that I have to be sure to be on top of service intervals and use good fluids. I have better than 4 years and 53k miles left in warranty, so I guess time will tell.
Thanks for the follow up. I got a similar answer, way less detail, than you. I'm still not buying it. I've ridden in a couple other jeeps with similar set ups and theirs feels completely different. Much firmer shift and zero slippage feel. I'm going to take mine back again here in a few weeks and see what they say again. I'll let you know if I get a different answer than I have been.
 

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Assuming FCA exposes the PIDs, you can figure this out with Torque. Monitor engine RPM, gear selected, torque converter state and torque converter slip. If I understand the issue correctly, the 1-2 shift is occuring below 2500rpm, but the torque converter is not locking until 2500rpm. All this should be visible in the data.

It may be worth a few calls to Superchips to see if you can figure out it their performance tunes turn off the eco shifting crap.

Mark

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This started for me in the last couple of months and I am now throwing P0740 code, just had fluid replaced today and after a couple of hours the same slipping occured and the code returned, I have 70k on a 2013.

I really don't want to replace the tranny this soon, I have read other threads that suggest the torque converter or valves? One local trusted shop said you can't just do the converter that most likely a tranny rebuild would have to happen?????
 
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