Aisin Shuddering shifting from P to D

[Hez]

Hi guys, tried searching for this but found nothing. I’m noticing in my 2021 3500 HO that I get a trans shudder from P to D. Seems like it’s getting more consistent but it absolutely does not feel normal/correct. Doesn’t matter empty or towing, Has anyone experienced this? Is there a re-flash available to fix this?

Thanks in advance!


Sent from my iPhone using Tapatalk

 

[Ostracize]

I've not heard of anything.
I'd start with transmission fluid level and color check.
Also I'd try and recreate in 4 hi and 4 lo to see if anything changes in the symptoms pattern.

 

[Ostracize]

... And try pausing in neutral for a tick in either direction. Note changes if any.

 

[Hez]

Ok we are pulling out tomorrow morning from Zion so I’ll try a few configs to see what’s what.
Truck only has 3k miles on it


‘21 3500 HO CC 4x4
Sent from my iPhone using Tapatalk

 

[JFV1134]

Mine also does this. I notice that if I hold the brake firmly it will not shudder. If I do not use the brake and go from neutral to drive it will shudder as well.

 

[boatdude1]

Hold the brakes firmly and it will be fine. Mine does that if the brakes are not held down really well.

 

[Hez]

Interesting find guys, so then are we feeling transmission shudder or brake shudder....
any thoughts as to why this is happening (internally)?


‘21 3500 HO CC 4x4
Sent from my iPhone using Tapatalk

 

[Ostracize]

Someone who knows more feel free to add or correct me but... The HO trucks have a different/larger torque converter which I would describe as very "tight".. Maybe due to higher pressures in the valve body of the aisin. I also have a '21 HO aisin and I find that if I don't pause in neutral before backing into a spot the TC doesn't have enough time to calm down from the fluid pressures causing unintended drivetrain noises. I would describe mine as a clunk from either rear-end gear lash or more likely u-joint give from the rotation change. This is normal.. As far as I've seen and I even experienced it to a much lesser degree in my previous '11 cummins 48RFE..
I just make it a habit to pause to avoid any undue mechanical stresses.

 

[JFV1134]

I have a few updates to this experience. I have noticed the shifting from Park to Drive within 5-10 seconds after starting the engine, no shudder is felt. If the engine runs for longer than that, there is almost always a shudder. If I am in Neutral and shift to Drive without touching the brakes, I still feel the shudder.