Power loss in reverse while backing out of my driveway - 2022 Dodge Durango GT Plus AWD - Pentastar V6 - 850RE

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Thank you, and thank you, I will reach out to @clinebarger and ask for advice. I wanted to ask here for help first to go back to the dealership armed with some knowledge.


I did not because I did not have a single shift issue. ****s are perfect every time. No slipping, no shudder, nothing. It just works perfectly. The issue I described above is the only one I have.

It's a ZF 8HP50 or 850RE (IIRC they are the same thing), so checking the fluid level involves getting underneath the vehicle with the engine running and the rear lifted about a foot off the ground. Then the fill plug has to be removed while the engine is running. I did a large-capacity oil pan upgrade on the RAM 1500 with the 8HP70, so I got the entire procedure engraved in my mind as I did three drains and fills with AMSOIL ATL. Also, these particular transmissions are filled before they are assembled into the vehicle, and they are considered sealed units by the dealership. The pan on the 850RE in the Durango doesn't even have a drain plug. I plan on upgrading to a PPE aluminum pan soon and HPL Green ATF. I doubt, however, that the fluid level is off. I appreciate the suggestion as it is very much valid.

Sidenote: supposedly, the fill plug is torqued to 35NM. When I took it off the 8HP70 in the RAM 1500, I used a 3/8" ratchet with a two feet piece of copper pipe as an extension, and I still had to use a lot of leverage to loosen it. It was on there like Hercules himself installed it. When they sealed and "filled for life," I guess they mean it.


I believe it. However, as far as I know, GM manufactures their transmissions in-house, while Stellantis buys them from ZF. If fact, most of my vehicle is made by ZF, including the front and rear diffs and the braking system.

The bottom line is that I will get to the transmission soon when I upgrade the oil pan. The dealership doesn't touch the transmission. I asked about fluid changes, and I was told, and I quote: "that unit is not serviceable."

Going back to what @PontiacHO said, my gut feeling tells me that sometimes, the torque converter clutch is not disengaged when I turn off the vehicle. It's just an assumption based on the fact that these ZF 8HP transmissions are programmed to disengage it at the very last split-second when you come to a full stop. At least in Stellantis vehicles they are this way. The RAM 1500 kicks almost whenever you downcoast from second to first gear and then stop. They even have a service bulletin about that and I downloaded it from Tech Authority. If anyone is interested please send me a message, or I will publish it if that's okay.

If it happens again, I will try and turn off the engine and turn it back on, and see what happens. I will update this thread, of course.

I don't know what's wrong with your vehicle as it's too new, But the ATF fluid level should be checked regardless of what anyone thinks they know.

I've been building, repairing & diagnosing automatic transmissions for over 25 years.....Fluid level is the first thing I verify.
 
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It sounds like the dealer isn't being very cooperative. Is there another dealer in your area? Typically, the first thing a tech will do is scan all of the vehicle's computers for codes.
 

Rod Knock

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It sounds like the dealer isn't being very cooperative. Is there another dealer in your area? Typically, the first thing a tech will do is scan all of the vehicle's computers for codes.
The part about being uncooperative is true. I also left our 2017 Santa Fe for a minor repair at their body shop and they've been giving me the run around for the past two months. This is the treatment I get after buying two vehicles from them. I will post about that in another threat with pictures and everything.
 
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The part about being uncooperative is true. I also left our 2017 Santa Fe for a minor repair at their body shop and they've been giving me the run around for the past two months. This is the treatment I get after buying two vehicles from them. I will post about that in another threat with pictures and everything.
Is there another dealer within a "reasonable" distance from your house?
 
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Sounds to me like a traction control, stability control issue causing the computer to cut power to the engine, apply brakes, etc.
If its only happening in reverse it's not the torque converter, the torque converter doesn't care about which direction the output shaft is turning
 
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I know I'm repeating and probably being irritating at this point, but the dealer needs to be made to solve this eventually. It could be very expensive. I'm thinking you've got no liability regardless of what happens when a tech is driving your vehicle. He represents the mfg who has sold you an unsafe vehicle.

Our Town and Country shudders in reverse going up hill. It's a common thing with the 62TE apparently. Which was rebuilt when it started imploding with 110k miles on it.
 

Rod Knock

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Is there another dealer within a "reasonable" distance from your house?
Yes, about the exact 25 miles away as this one is, but in a different direction. I got the RAM 1500 from that dealership, and they aren't stellar either.

Sounds to me like a traction control, stability control issue causing the computer to cut power to the engine, apply brakes, etc.
If its only happening in reverse it's not the torque converter, the torque converter doesn't care about which direction the output shaft is turning
That makes sense, considering that I found a brake pad imprint on the rear left brake rotor. And I don't abuse the brakes, so that could only be from the traction control system.

I know I'm repeating and probably being irritating at this point, but the dealer needs to be made to solve this eventually. It could be very expensive. I'm thinking you've got no liability regardless of what happens when a tech is driving your vehicle. He represents the mfg who has sold you an unsafe vehicle.

Our Town and Country shudders in reverse going up hill. It's a common thing with the 62TE apparently. Which was rebuilt when it started imploding with 110k miles on it.
You're right. The dealer has to make good on it. But this time around, instead of beating around the bushes at the dealerships, I will file the appropriate complaints first so that I won't be either run off by or BS-ed by the service advisor when I go to the dealer.
 

Astro14

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Since you’ve said that you start it in neutral, and you get a flashing N, before putting it in reverse, I have to ask:

What happens when you start it in park, and then shift to reverse?

It sounds electrical - like the TCM thinks you’re still in park, hence the flashing N.

That may not throw a code.

I would try starting in Park, select drive. See if you feel the parking pawl disengage, then select reverse.

This thing is completely electrically controlled, right?

There’s a fault in there - one sensor that should show open is closed and the computer is not sure what to do. That’s my guess.

Wondering is going to drive, then reverse ends up with the same fault.
 

Rod Knock

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Since you’ve said that you start it in neutral, and you get a flashing N, before putting it in reverse, I have to ask:

What happens when you start it in park, and then shift to reverse?

It sounds electrical - like the TCM thinks you’re still in park, hence the flashing N.

That may not throw a code.

I would try starting in Park, select drive. See if you feel the parking pawl disengage, then select reverse.

This thing is completely electrically controlled, right?

There’s a fault in there - one sensor that should show open is closed and the computer is not sure what to do. That’s my guess.

Wondering is going to drive, then reverse ends up with the same fault.
Yes, the 850RE has "e-shift," just like all ZF 8HP transmissions. When a gear is flashing on the selector it means that the transmission is not in that gear.

I forgot to mention that when I turn right sharply and apply power I hear something like a buzzing or grinding. Since I changed out the gear oil, I can say for sure that the diffs were filled to the correct level. @Tman220 might be right, it might be an electronic issue related to the traction control system, and the buzzing/grinding that I hear when I turn right might be an ABS valve as they tend to be loud when engaging. I purged them on the RAM 1500 using AlfaOBD when I did the brake fluid flush last hear and they are loud when they engage.

You and @Tman220 are right, it must be an electronics-related issue. Now, I hope I can get to the bottom of it somehow.

These Durango SUVs had an ABS recall, however, I checked that, and mine wasn't part of the recall.

Thank you for your help.

[Edit]
@Astro14

In reference to this:
That may not throw a code.
The recall reads:

Chrysler (FCA US, LLC) is recalling certain 2019-2022 Ram 2500 and 2021-2022 Dodge Durango vehicles, and 2019-2022 3500 cab chassis with GVWR less than 10,000 lbs. The ABS control module software may prevent the electronic stability control (ESC) malfunction indicator light from illuminating during certain conditions.

I should drive with traction control turned off and see if it makes any noise when I sharply turn right.

Thank you again for the idea!

I have to see if I can verify if this vehicle had the recall originally and if the dealer "fixed" it before they put it up for sale. That would be a pretty big violation of the law on their part.
 
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Sounds to me like a traction control, stability control issue causing the computer to cut power to the engine, apply brakes, etc.
If its only happening in reverse it's not the torque converter, the torque converter doesn't care about which direction the output shaft is turning
Not to challenge what you are saying. Your opinion is as valid as anyone’s. The torque converter clutch applies by electronics. My thought was there may be a programming issue. I thought he said that the engine would only make 500 rpm when this situation occurred. If the converter was “free” even with park brake applied it will rev substantially more. I do realize that these systems kill rpm, apply the abs, and all but stall when there is a perceived need to “gain control” of the vehicle; ie, skid etc. You probably are on to the right area with the traction control. Good call.
 

Rod Knock

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Not to challenge what you are saying. Your opinion is as valid as anyone’s. The torque converter clutch applies by electronics. My thought was there may be a programming issue. I thought he said that the engine would only make 500 rpm when this situation occurred. If the converter was “free” even with park brake applied it will rev substantially more. I do realize that these systems kill rpm, apply the abs, and all but stall when there is a perceived need to “gain control” of the vehicle; ie, skid etc. You probably are on to the right area with the traction control. Good call.
It doesn't feel like the engine is fighting the transmission, but rather like throttle control is taken away from me and the engine is killed off.
 

OVERKILL

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I agree with much of what has been suggested thus far:
1. Check the ATF fluid level
2. This vehicle has hill start assist, correct? Try disabling that. It may not be disengaging.
3. If 1 and 2 don't work or don't yield anything useful, try, as you noted, with the traction control disabled.

Barring that, you'll have to work with your dealer, despite how much of a PITA it is. I was without my '16 SRT for quite a while after the accident and intermittently when it had a lose ground near the battery that the tech didn't find and was throwing parts at it (new alternator for example).
 

Rod Knock

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1. Check the ATF fluid level
Though I know you're absolutely right, I will leave this one for last because my driveway is not level. When I did the fluid change on the RAM 1500 I had to raise the rear on ramps and take almost all tire pressure out the driver side front and rear tires to get the transmission perfectly level to check the fluid after the third and final fill. I more than likely slightly overfilled it the first two times by about an ounce.

2. This vehicle has hill start assist, correct? Try disabling that. It may not be disengaging.
Good suggestion as I enabled that since I got the vehicle and left it like that. My driveway is slightly inclined so that might be a problem when the vehicle is nose-down.

3. If 1 and 2 don't work or don't yield anything useful, try, as you noted, with the traction control disabled.
I'll try that today when I go to take my shipments to UPS in a bit and will update this thread.

Barring that, you'll have to work with your dealer, despite how much of a PITA it is. I was without my '16 SRT for quite a while after the accident and intermittently when it had a lose ground near the battery that the tech didn't find and was throwing parts at it (new alternator for example).
I know you're right, and yes, they are. Currently, I'm trying to get our 2017 back from their body shop and probably will never set foot there again. I have a few other options, or worse case, I'll find a decent dealer in Charlotte. I'd rather drive an hour and a half each way and have this issue fixed than waste days-on-end with the current dealer.

That’s too nice a vehicle to have these issues. I’m in NC also. What dealer are you using for warranty repairs?
I'm not sure if I can publically post business names on the forum, so just to be safe, I will send you a private message with this information in a bit. I am tied up at the moment, it's been a crazy week so far.
 
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