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Clunk/thunk on 6-5 coasting downshift.

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47K views 250 replies 37 participants last post by  SRTNinja  
#1 · (Edited)
I'm scheduled to have my 2015 SRT looked at by a Chrysler field tech this coming week. Has anyone else here had a problem with a rough 6-5 downshift causing a clunk/thunk noise with a jerking sensation? This will be my third visit to the dealer for this issue. The first visit involved replacing the transmission valve body which did nothing to improve the problems the second visit was to make sure all software was up to date and to tell me that all Jeep SRT's have this clunk and that it's a normal condition for this vehicle. I'm just not buying it. Why would it only do this on a 6-5 downshift?

Please help my reaffirm to myself that I'm not crazy and that this is NOT a normal condition.

I'm hoping that this Chrysler field tech brings a fresh opinion to my dealer service department and does not suffer from the "they all do this" mentality.


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R
#2 ·
FWIW mine does do this intermittently (~600 miles total, 400 of which were today driving up to San Jose on the highway), enough that I've noticed it but not enough that I am overly concerned. It's also not as severe as some have described. About 30% of the time it doesn't do it at all, and I don't tend to notice it as much under braking, or really at all when paddle shifting.
 
#4 ·
I have a 2014, and have had all the TSB's done and while it is not severe - it is a noticeable 'loading up and then release' when downshifting from 6th to 5th - especially in Auto/Eco mode.

Look in the troubleshooting section one poor chap has had a hell of a time
 
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#7 ·
I have a 2014 with 20,000km on it and it does the same. Not so much on a long slow deceleration, but some of the quicker, shorter stops, which makes it even scarier. I've had the tsb relearn as well.
From what I've read on this forum the only thing that works is disconnecting the battery for a minimum 8 hrs and then the transmission does a relearn of the driving habits. Take it easy for the next 800 miles. Don't quote me on this one folks. Haven't tried it myself.
 
#8 ·
Mine is more a problem at the slower leisurely stops. If I stop suddenly it still clunks, but not as bad. Possibly because it just goes past 5th quicker. Also my trans temp yesterday on the highway at 77mph was right at 201 degrees F. Seemed kind of high considering it was only 23 degree F. outside.


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#11 ·
Did a battery 'reset' overnight last night - didn't help my suspension issue - but the trans seems better on 6th to 5th --- but my old problem of 5th to 4th is back... FML. Maybe I will just start driving with paddles all the time...

I'm beginning to think this is just something we have to live with boys... :(re-program, re-learn and hope it isn't too bad... (but if it jars your brain, it should be fixed right... good luck to those who have it that bad!)

for the rest of us...Drive it like you stole it and the Hellcat Jeep will be out by 2017/18 and we can all upgrade and hope the trans lasts until then...
 
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#13 ·
I could live with that too, but mine does it almost every single time. I actually celebrate when it fires off a smooth 6-5 shift. My wife won't stop pointing it out too, which doesn't help with my frustration. I'm going to start leaving the keys in it with the windows down in a shady part of town. It's such a shame because it's a wonderful vehicle otherwise. That 6.4l Hemi will make you forgive a lot of sins, but the 6-5 shift is dragging me down.


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#15 ·
I've got the same thing, but it's more like the 5-4 shift for me.

I'm taking it in to Jeep in a few week so they can have a closer look. The attitude so far hasn't been encouraging.

I've also got a rough idle on cold start and my U-Connect crashes if I plug my iPhone6 in via the USB cable. So far they've told me there's nothing they can do about any of them. I LOVE the car, but unfortunately Jeep service isn't always the best. It's an unfortunate tarnish on such a great vehicle.
 
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#16 ·
I get the occasional rough idle at cold start too. I'm letting that one go. I can only imagine my device departments reply to that complaint. I'm thinking about getting the service manager a rubber stamp that says "They all do that"...I'm not kidding. If they all do it why doesn't Jeep fix it. That answer just pisses me off.


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#17 ·
I know it's a different tranny for us 12-13s but I had a similar issue with the 2nd to 3rd shift or the"bog" down issue. Might have took them 3 years to fix but ended up going to service for a transmission module update and now there's no more rough shifts or the bog down issue. Hopefully it's just a computer adjustment down the road for you guys and nothing serious.


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#19 ·
Update.

My service department is now going to push Chrysler for a new transmission and torque converter because of the awful drone I've been having the past couple hundred miles. The district manager has to sign off on it though, so it's not a done deal yet. I should know more tomorrow.

I've been having an awful drone the past couple hundred miles when the torque converter locks up at highway speeds. I brought it up with the tech today as I thought the issues may be related. Glad I did. The tech has 20 years of transmission repair experience so I'm taking his word for it. Fingers crossed will update when I hear more.


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#20 · (Edited)
Is the drone related to the 6-5 clunk or separate issue? Mine does some funky things also when coasting and then hitting the accelerator - almost feels like it's in a gear way too high for the speed, slight clunk and then Acceleration. Ours were built around the same time. Wonder if there's an issue with that batch of trannys?


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#21 ·
I believe the two are separate, but perhaps the tranny damaged the torque converter. I really don't know. It started with the clunk on 6-5 and has progressively gotten worse.

The drone didn't start for me until a couple hundred miles ago(at about 1300mi on it) it had 1551 on it today when I dropped it off at the dealership. The drone was getting louder and happening at higher speeds. I first noticed it around 40 then it would happen from 40-63 mph then last weekend I was taking my niece home and was doing about 75-77 mph on the highway and it started doing it at that speed also. Only when the torque converter locked up at steady speed and load. As soon as I'd press on the gas or the cruise control would it would come out of lockup and smooth out. If I put the trans in sport mode it would not drone. I think because the converter doesn't lock ups? Someone correct me if I'm wrong, but I couldn't feel it lock up in sport mode. Also the trans temp would climb above 200 degrees at a steady 77mph. I'm hearing this is a normal temperature, but it seems high to me considering it was only 23 degrees F. with only my wife, niece, and myself in the vehicle. It also seemed to slam in and out of lock up a lot at steady speeds for no apparent reason. I thought at one point it was the AC compressor kicking on and off, but I turned the climate control off and it continued to do it. I also tried Eco mode at 75-77 mph and the drone/vibration was UNBEARABLE. not just slightly annoying, but nauseating. My wife gave me the look of death so I turned it off. She just shook her head. She is hating this Jeep at this point. I've had performance cars with aftermarket exhaust before so I know what drone is. This was unholy. If you want to get a terrorist to talk take him for a ride in this jeep. Water boarding has nothing on it.

Should know more tomorrow. I'll update.


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R
#22 · (Edited)
Isn't the drone you're talking about in D but not S mode at steady speed the MDS system or whatever kicking in when it drops cylinders for fuel economy? Mine does the exact same thing, and it doesn't do it in S because I understand S mode disables the MDS system, or at least greatly reduces when it comes on.

I understand MDS is completely disabled if you turn the Selec Trak dial away from Auto (like into Sport), try doing that and see if the drone ever appears?

Unrelated, but regarding the A/C compressor, it's pretty gnarly at idle with foot on the brake when it kicks in, the truck will almost jump a tiny bit when it idles up...definitely noticeable.

My 6-5 clunk remains intermittent in volume and harshness after 1300 miles (admittedly many were highway as we had to take a road trip starting with about 300 miles on the truck). I've been driving it a lot harder the last couple days and I can almost convince myself it's improving, but overall I agree the transmission in this truck is pretty jumpy.

Remaining quite interested in this thread though as we all have similar build times with this issue.
 
#23 ·
The drone is happening in D without sport shifting selected. Gets even worse if I put it in Eco mode. If I select sport shifting the drone goes away and the Eco mode is disabled.

At this point I'm wondering if the trans damaged the torque converter or if the converter damaged the transmission. I may never know. My troubles started with the 6-5 clunk at slowing downshifts and has escalated to the clunk with droning now. I don't know enough about transmissions to give an honest answer about what may have happened. I'm just being honest about my SRT's symptoms so that others may match them up to theirs and have an easier time with their fight at the dealer.


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R
#24 · (Edited)
Well having not sat in your car I can't speak to the specific volume of the droning issue you're experiencing, but I know I have a distinctly notable exhaust note change in cruise which I attribute to the activation of the MDS...in fact this was so noted by Chrysler that the 2015 models actually have the noise cancelling system with the microphones in the cab just to address the relative unpleasantness of the MDS "drone" if you will. Having not ridden in a 2014 without the noise canceling system, I can't say as to whether the drone is quieter in the 2015, but I do know that A) I definitely notice the change from MDS active to MDS off and B) it's not terribly loud or obnoxious, just noticeably different. Only does it in D to any extent, worse in Eco, and doesn't do it at all in Sport or Track mode.

Is there a reason you specifically believe the drone you're experiencing is directly related to the torque converter and not the MDS system?
 
#26 ·
I didn't have any jerky jerky behavior in my SRT, except for the 6-5 down shift. ALL other shifts were butter smooth. The 6-5 downshift just produced a clunk/thunk noise along with jerking your body forward. again, ALL OTHER shifts were butter smooth for me.

As far as the drone goes, to my knowledge there is no activation of the MDS system by default on the 2015. You have to actually press the ECO button on the center stack to engages it. When mine was new(it only has 1551mi)no drone was present when the ECO was in the default off and only a slight drone when engaged. The drone I've got now is more like a drone/vibration that your ears feel but also your butt.

There has been a steady escalation in the drone since about 1300 miles with my trip to the dealership being uncomfortable at any speed above about 40mph.

I can understand a vehicle of this nature having some exhaust drone/vibration, but mine was pretty obvious that something was wrong. It was just way to rapid of a decline.



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#29 ·
New tranny and torque converter on the way. I won't know till tomorrow when they'll have it. I may be getting it back as is until the new tranny comes in if Chrysler deems it safe to drive. I'm fine with that because the minivan rental, Enterprise set me up with smells like a Tijuana prostitute.


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#30 ·
I just got finished washing my SRT after picking her up last night and putting some miles on her today. I'm happy to tell you all the new transmission is a night and day difference. No more 6-5 clunk just a nice firm shift without jerking me forward. I put about 60 miles on it since I picked it up and it just seems to be improving. I think this tranny is actually learning to improve it's shifting, unlike the original. It acts like a completely different vehicle and I'm pleased with it. I'll put some more miles on it and report back with any issues.

The only thing I wasn't happy about, was after picking it up last night, I heard a tink, tink noise then looked behind me and saw something in the road. I thought it was a socket at first, but then doubled back to be sure. Turns out it was about a four inch long bolt, so I picked it up out of the roadway and burnt me fingers, confirming it was from my SRT. So I high tailed it back to the dealership to make it there before close. Turns out it was one of the bolts holding the exhaust to the exhaust manifold on the left side. Tech promptly reinstalled it and apologized and I was on my way.


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#31 ·
Good to know your persistence paid off. I had a serious clunk issue with my 07 years ago, so I know the feeling of decelerating and feeling like the truck just got rear-ended. Was disappointed to hear the problem still existed to some degree on the WK2's. Good luck with the new transmission.


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