Surge when letting off brakes

[91TTZ]

I have felt this as well, but I only notice it when I first start the truck for the day. I always let it sit for 30 seconds or so before I drive, but it seems to lunge forward as I pull out of my spot when letting off the brakes.

 

[FastBlackRam]

So just to clarify, I can hear my engine rev slightly when this happens. That doesn't seem like a driveshaft issue. Just saying.

 

[lamerem]

**UPDATE**
The dealer took the truck in and had no issues recreating the problem with the transmission feeling like it was going in to gear when letting off the brake. They believe the valve body within the transmission is the culprit and got it approved through Ram to replace under warranty. The valve body of course is on national back order, so who knows. I was instructed to continue driving the truck as normal, and what not. The dealer also said if this doesn't work, then they would work with Ram on replacing the transmission. He assured they would get to the root of the issue. I love my dealer, and feel bad for you guys that are mistreated by yours.

I'll update again when the work is complete.

 

[irishwake63]

I have this issue as well and I believe it is the brakes not releasing in sync a delay from rear brakes

 

[lamerem]

I have this issue as well and I believe it is the brakes not releasing in sync a delay from rear brakes

In my case it is not the brakes. It doesn't do this in Tow/Haul mode. If it was the brakes it would do it during that driving mode as well. You should check to see if yours performs the same or normal in Tow/Haul mode.

 

[StreetRossi]

I have now joined the “Sloppy Transmission” lunge forward club

Hey Everyone,
Roughly 17,000 km on my truck. 2022 Ram 1500 Sport Night Edition Crew Cab 4X4. Rear Axle Ratio: 3.21. (Non-E-Torque).

When slowing down right before a complete stop say approaching a stop sign, stop light or another car. Periodically my RPM Drops to 250 very low then jumps to 1000+ RPM.

Almost feels like the truck is going to stall out then is lunging the truck forward with the brake pedal pressed all the way down. When it lunges it’s very aggressive and clunk type noise is coming from somewhere.

It doesn’t do this all the time and definitely seems to be happening more frequently as the weeks pass. The second scenario is sometimes the same thing happens when just letting my foot off the gas pedal while driving. Clunk and surge forward.

Truck just started doing this over the past few weeks. Went to speak with my local service manager today at the dealership I got to for oil changes.

He said unfortunately they are aware of some ZF transmission issues that are affecting some customers trucks. They have a process they need to take which is understandable in order to get FCA to cover jobs and go through the proper steps.

After showing him some of the videos on my phone, they are starting with replacing the Transmission Valve Body sometime next week when the part comes in.

If that doesn’t work or damage is already done then he said we”ll be speaking about a rental, leaving my truck and a full transmission replacement. Thank god for warranty but so disappointed. So far looks like the dealership is willing to help and we’re nice about everything. They have also done a few transmission replacements already.

Truck drove like a dream the first 15,000 km. Never towed, never off-roaded. Just a fully loaded street truck that goes back and forth the work, errands and has been well looked after both inside and out. I’ll update this thread as the repairs and fixes start.

 

[lamerem]

***UPDATE***
The dealer brought the truck in back in the middle of May and replaced the rear brakes. Both calipers, brackets and hoses were replaced. There was no change in the "bump" from this procedure. They then found some "Tech to Tech" case that had the same issues. They pulled the drive shaft (I have the one piece shaft) and removed the pinion flange from the rear end. They applied anti seize to the pinion splines and reassembled. The put a new nut on the pinion and torqued to specification (unknown what that spec is).

This was done at just under 43k miles. I now have just under 49k miles and the bump has returned. So I think what is happening is the nut on the pinion spline is backing off the torque ever so slightly and allowing movement of the pinion.

Here are the parts they ordered:
6507901AA Pinion Nut
6506497AA Bolt-Hex Flange Head Locking (these are for the drive/prop shaft to pinion)

 

[irishwake63]

In my case it is not the brakes. It doesn't do this in Tow/Haul mode. If it was the brakes it would do it during that driving mode as well. You should check to see if yours performs the same or normal in Tow/Haul mode.

I notice my doesnt do it if I have my airbags filled up so I am thinking there is play in the shaft