[Durangutan]

Thanks Admins for repairing the thread! I am re-opening it now and consolidating the other one I opened into this one. Appreciate it! (And anyone not visiting earlier today will have no idea what I'm talking about.)

 

[mnunes]

Any update on your situation? Sounds like we are in a similar boat. Really not wanting to replace the trans just to see it happen again. Wonder how close our build dates are to eachother.

Yesterday, dealership performed the U06 recall (they had to, otherwise FCA likely wouldn't advise them further on the downshift issue). Upon test driving after the recall, downshift issue still there. So today, dealership is replacing the valve body and transmission fluid. Waiting to hear back. Have a STAR case now

So I can confirm the U06 recall does not cause the downshift issue (since my vehicle had the issue before the recall) nor does it solve the issue (since it still occurred immediately after the recall work). Unfortunately now i have to deal with the stupid autopark functionality.

One possibility is the U65 recall (which i had done on May 23, 2018) although the downshift problem really didn't begin until colder weather this past November/December 2018 (post #36).

I had to cancel the appointment I had so I haven't been back to the dealer since. The problem hasn't gotten any better, after some 2000 miles and about 4 months, including a 1000 mile road trip (all highway) which is very unusual for me - I thought that changing my driving might make a difference. If anything, the 2>1 downshift has gotten rougher in that time, too.

Can anyone confirm that the problem goes away if you paddle shift instead of let the transmission automatically downshift? I've done this countless times at the exact same speed and rate of deceleration. When it's in "D" it's rough but when I paddle shift it's perfectly smooth. This tells me that it's a programming issue rather than a mechanical one since it proves that the transmission *can* downshift smoothly at the same speed.

 

[mnunes]

Thanks Admins for repairing the thread! I am re-opening it now and consolidating the other one I opened into this one. Appreciate it! (And anyone not visiting earlier today will have no idea what I'm talking about.)

Many thanks!

 

[thkbaron]

I had to cancel the appointment I had so I haven't been back to the dealer since. The problem hasn't gotten any better, after some 2000 miles and about 4 months, including a 1000 mile road trip (all highway) which is very unusual for me - I thought that changing my driving might make a difference. If anything, the 2>1 downshift has gotten rougher in that time, too.

Can anyone confirm that the problem goes away if you paddle shift instead of let the transmission automatically downshift? I've done this countless times at the exact same speed and rate of deceleration. When it's in "D" it's rough but when I paddle shift it's perfectly smooth. This tells me that it's a programming issue rather than a mechanical one since it proves that the transmission *can* downshift smoothly at the same speed.

Granted I've had mine (well my wife's) only a few days but I putzed around town with it tonight using paddle shifts and it's just fine. I'm currently dealing with a possible lifter problem already. Thank god I have a warranty still.

 

[Iowa RT]

I had to cancel the appointment I had so I haven't been back to the dealer since. The problem hasn't gotten any better, after some 2000 miles and about 4 months, including a 1000 mile road trip (all highway) which is very unusual for me - I thought that changing my driving might make a difference. If anything, the 2>1 downshift has gotten rougher in that time, too.

Can anyone confirm that the problem goes away if you paddle shift instead of let the transmission automatically downshift? I've done this countless times at the exact same speed and rate of deceleration. When it's in "D" it's rough but when I paddle shift it's perfectly smooth. This tells me that it's a programming issue rather than a mechanical one since it proves that the transmission *can* downshift smoothly at the same speed.

Yes I can confirm no downshift issue when using paddle shifters. I agree it is a program issue, but its an issue that is causing mechanical damage if there are shavings reported in fluid. It is also something i believe specific to the durango/maybe JGC as i've never heard of this reported in 4th gen Rams and many of those are on the road. I think it must be something that cannot be fixed with a flash or adaptive resit, which is concerning. Unless once your trans is damaged from an original program issue it cannot recover.

I've also thought I've felt some slipping in light acceleration in 3rd/4th gears when coming from a rolling stop. Like the engine is reving slightly more and it takes a bit for the trans/vehicle speed to match what i'd expect the acceleration/engine RPM to be. But it may just be because i'm hyper focused on the transmission behavior right now.

Anxiously awaiting the call from the dealer reporting fluid condition (was it low, burnt, any shavings?) but i surprisingly did not receive a call yesterday....I may call them.

 

[Iowa RT]

I have a theory, based on this document:
https://docplayer.net/45447397-Tran...5447397-Transmission-control-module-tcm-adaptation-8hp45-845re-8hp70-8hp90.html

Issue is clutch B, and how it is fast fill adapting (or not) on the fly. A 5-4 downshift involves clutch B and D i think. Conditions under which clutch B will fast fill adapt is coasting with throttle at 0 position between gears 6-5. That often precedes a 5-4 downshift.

When i think back to when this occurs and how my driving style is (early coasting to reduce brake usage and a lot of around town driving never going much above 6th gear) i think the above conditions are occurring relatively often, and clutch B is either adapting improperly or not adapting/filling correctly or the clutch is worn. To be honest i'm not sure what that means but it would make since as it almost feels like the 5-4 downshift surge could be caused by a stuck or damaged B clutch. It would also explain the light slipping i thought i felt when accelerating in the lower gears that clutch B operates (1-5 and R)

If they perform a quick learn procedure to resit the adaptive, it should resolve the issue. My guess is the issue comes back pretty soon because we either have permanent clutch B damage or clutch B is not learning to act properly under our driving conditions.

Or it could be clutch C I guess - just throwing things on the wall and seeing if someone more knowledgeable can figure this out.

 

[RedHeckle]

Yes I can confirm no downshift issue when using paddle shifters. I agree it is a program issue, but its an issue that is causing mechanical damage if there are shavings reported in fluid. It is also something i believe specific to the durango/maybe JGC as i've never heard of this reported in 4th gen Rams and many of those are on the road. I think it must be something that cannot be fixed with a flash or adaptive resit, which is concerning. Unless once your trans is damaged from an original program issue it cannot recover.

I've also thought I've felt some slipping in light acceleration in 3rd/4th gears when coming from a rolling stop. Like the engine is reving slightly more and it takes a bit for the trans/vehicle speed to match what i'd expect the acceleration/engine RPM to be. But it may just be because i'm hyper focused on the transmission behavior right now.

Anxiously awaiting the call from the dealer reporting fluid condition (was it low, burnt, any shavings?) but i surprisingly did not receive a call yesterday....I may call them.

Damn, sorry this transmission issue is still haunting you. I had seen that clutch document also (actually a very informative read). I had also noticed that using the manual paddle shifter that the shifts were smooth. I'm hoping FCA treats you right and fixes the issue. I had my transmission swapped 3,000 miles ago for the same issues. It took FCA 4 days to approve the trans swap. After that, wow, I had forgotten how smooth the shifts are. I did have one "hard" downshift (8>5)when trying to pass a car at 75mph but that was early on and I'm chalking that up to TCM learning.

Good luck!

 

[Iowa RT]

Update (not much of one)

Durango has been at the dealership going on 5 days. Day 2 they were supposed to replace fluid and valve body. Day 3 i called requesting an update. Was told they are waiting on approval to install the valve body. FCA wanted pictures and had to approve of the valve body install for some reason (they have one ready to go in). Day 4 nothing. Its now day 5.

This tells me either the issue is with the valve body or FCA is waiting to decide on a new valve body vs new transmission. Either way i'm not expecting to get it back soon. Dealership said the fluid looked good.

Now I'm curious if Durango's have a different valve body part number than Rams, to explain why similar complaints haven't occurred with Ram trucks. Or if there has been a part revision on vavle body's like there was with the water pumps.

Anyway, if others have 5-4 downshift lunges, it looks like it cannot be fixed with a reflash or a new transmission control module or an adaptive reset. It takes either new fluid and a valve body or a new transmission. I'll know soon enough

Here is a nice document, for your reading pleasure
http://perception.fcaperformanceinstitute.com/FCARepository_con/topiccontent/1588106484/0221308.pdf

 

[Iowa RT]

Seems like the valve body may be the culprit.

Here is a website has has a bunch of valve kits to resolve shifting issues
https://www.sonnax.com/parts?&categories[]=3&makes[]=20&unit_relationships[]=439&unit_relationships[]=435&unit_relationships[]=9&areas[]=4

 

[Iowa RT]

Update:
After 15 days at the dealership, got the durango back yesterday.

Replaced valve body (R8227332AB) and fluid (68218925AA), programmed TCM, and "performed drive learn"

They also performed the U06 recall which updated the TCM from 68249348AF to 68249348AG.

All covered under powertrain warranty vehicle has just over 43k miles

The valve body used to have a different part number ...AA, so the revision may have been made to correct this issue, or not. Looks to be the same one used for ram, charger, grand cherokee, and durango.

 

[RedHeckle]

Glad to hear you have your ride back finally! Hopefully that solves the issue. When they replaced my valve body back in December 2018, PN: 68227332AD was used. I think this is new versus rebuild? (Just going off information online). But that may be a mute point since they replaced the whole transmission in January 2019.

Good luck!

 

[Iowa RT]

Glad to hear you have your ride back finally! Hopefully that solves the issue. When they replaced my valve body back in December 2018, PN: 68227332AD was used. I think this is new versus rebuild? (Just going off information online). But that may be a mute point since they replaced the whole transmission in January 2019.

Good luck!

Well that's a little concerning. The service department did say they had one already... which means they had a remanufactured one R8227332AB setting on the shelf and chose not to order a new one 68227332AD.....

Or now i'm wondering if the reason had to wait so long was because they sent my original valve body/core out to get refurbished....

Their excuse was that they have a valve body setting and waiting to go in but couldn't until they got official approval through STAR or chrysler...said they asked them for pictures, etc.

I assume official verbiage in the powertrain warranty allows them to do this, as opposed to replacing with a new part.

 

[mnunes]

Improvement or placebo effect or ????

Since it seems that the whole issue has to be programming and how the transmission is learning and adapting over time, I decided to try an experiment. I've been saying for a while that when I paddle shift, the shifts are smooth. IowaRT's posts and linked transmission docs got me to thinking about ways to get the transmission to learn some smoother shifting habits.

As an experiment, I drove for a couple days where anytime I was decelerating to a stop (say, from 40mph or higher) I'd just tap the paddle once and let the transmission downshift the rest of the way on its own (which it does as your speed drops). Perfectly smooth, as expected. The downshift points are a little lower than if I was in "D" but no big deal.

The interesting thing I noticed is that when I'm driving in "D" now, the downshifts seem significantly improved. There are still some that are just as rough as before, but there seem to be plenty where I would expect it to be rough but it's not bad enough to complain about. Time will tell how this pans out, whether it learns its rough shifting again.

Or I could just experiencing the placebo effect. Or I could have adjusted my driving habits to minimize the conditions that result in rough shifting.

I'll let you know.

 

[Iowa RT]

Reporting back - the new/refurbished valve body has completely resolved the downshift issue. Also have seen an improvement to MPG.

 

[Ludakris04]

I know most of this seems to be R/T related, but I have had similar issues with my 18' SXT. I dont drive alot, and at 700 ish miles I started having an issue where it would basically "surge" when going down the road in 8th gear. Between 40-65 if I was just maintaining speed it would act like it was trying to shift, but wouldnt. RPMs didnt change. So I took it in, of course they couldnt recreate it and so they said they flashed it and it should be good. It still did it, but I started driving it more and more (longer trips), figuring it might be a learning thing. The surging stopped, but now the downshifts have started. Mine is the downshift to 5th gear. It is just as everyone else describes with the surge. Also, when I start mine up when its parked, it clunks.. like as if I put it in gear. But it is still in park.
I complained to the dealer about that and they said they could replicate it.

Our other vehicle is a 16 GC, and it has never had any issues like this with the shifting. It has low miles as well, 13K. Just kind of frustrating because it seems very apparent to me.

 

[mnunes]

Reporting back - the new/refurbished valve body has completely resolved the downshift issue. Also have seen an improvement to MPG.

Hopefully everything stays good on yours. Mine was good for about 2 weeks after the transmission was replaced, then suddenly one day it was shifting hard again.

Edit: that was about 100 miles.

 

[mnunes]

I know most of this seems to be R/T related, but I have had similar issues with my 18' SXT. I dont drive alot, and at 700 ish miles I started having an issue where it would basically "surge" when going down the road in 8th gear. Between 40-65 if I was just maintaining speed it would act like it was trying to shift, but wouldnt. RPMs didnt change. So I took it in, of course they couldnt recreate it and so they said they flashed it and it should be good. It still did it, but I started driving it more and more (longer trips), figuring it might be a learning thing. The surging stopped, but now the downshifts have started. Mine is the downshift to 5th gear. It is just as everyone else describes with the surge. Also, when I start mine up when its parked, it clunks.. like as if I put it in gear. But it is still in park.
I complained to the dealer about that and they said they could replicate it.

Our other vehicle is a 16 GC, and it has never had any issues like this with the shifting. It has low miles as well, 13K. Just kind of frustrating because it seems very apparent to me.

The 2018 V6 Durango uses a slightly different version of the 8-speed transmission (8HP45/845RE for the V6 vs. 8HP70 for the V8). Which engine is in your GC?
The variant for the V8 is beefed up a bit, not sure how similar the programming is between them. Given the differences in mechanicals, I would expect them to operate slightly differently.

 

[Ludakris04]

The 2018 V6 Durango uses a slightly different version of the 8-speed transmission (8HP45/845RE for the V6 vs. 8HP70 for the V8). Which engine is in your GC?
The variant for the V8 is beefed up a bit, not sure how similar the programming is between them. Given the differences in mechanicals, I would expect them to operate slightly differently.

Both are V6.
Everything driveline wise it the same.

2016 GC Laredo 75th Anniversary
2018 DD SXT Plus Blacktop

 

[mnunes]

As an experiment, I drove for a couple days where anytime I was decelerating to a stop (say, from 40mph or higher) I'd just tap the paddle once and let the transmission downshift the rest of the way on its own (which it does as your speed drops). Perfectly smooth, as expected. The downshift points are a little lower than if I was in "D" but no big deal.

The interesting thing I noticed is that when I'm driving in "D" now, the downshifts seem significantly improved. There are still some that are just as rough as before, but there seem to be plenty where I would expect it to be rough but it's not bad enough to complain about. Time will tell how this pans out, whether it learns its rough shifting again.

Update: just over a week and shifting is back to being consistently rough. I'll probably try this again but I'm hoping that someone's experience with a dealship fix works long-term.

 

[RedHeckle]

Update: just over a week and shifting is back to being consistently rough. I'll probably try this again but I'm hoping that someone's experience with a dealship fix works long-term.

Crap man. I had similar issues after driving 300 or so miles, after they put in a new transmission valve body. So, back to dealer, where we waited for FCA to approve a full transmission replacement. All good so far *knocks on wood* after 6000 miles. Good luck!