Driveline chunking

[Benito]

New to TDR. I have a ‘14 Laramie 4x4 CTD that I have owned from new. It has 67k miles on it now. At about 62k I started hearing a slight hum from the rear end. I took it to the dealership, (under Ram Max care coverage). They said the pinion bearing went bad which caused other damage of course. They rebuilt the rear end. The truck felt fine for a bit but recently I have noticed a chunking feeling when I back off the throttle, (more than usual) -almost like when my 5th wheel is hooked up and I back off. I have not towed since the rear was done. I live near Atlanta and commute in so most driving is highway with traffic. Any thoughts on what it could be? If it was not because I just had the rear done I would have thought it was the trans/torque converter.
I will take it back in but I would like to have a little direction before I do. I don’t have a lot of confidence in my local dealerships FYI- My truck was in for over 2 weeks for the rear end rebuild.

 

[Thump]

Does it also do this when you put it in gear or going from reverse to drive (or vice versa)?
Having had the rear end redone, it could be any number of things from driveshaft carrier bearing to gear lash.
From a gearset change out, I'd be suspicious of the pinion, again. I've not opened one of the later axles up, so I don't know if it has a crush sleeve. If not properly done, those can cause all manner of problems down the road.
Also, just saw where a buddy of mine had his 2013's T case scatter on the road, literally. Chain was just hanging down with a trail of fluid and metal bits behind him.
Don't mean to scare ya, just don't want to make light of it, either.

 

[Benito]

Thanks for the response. No issue changing to drive or reverse. I thought it was gear lash as well but does not happen all the time. The transfer case could be but don’t think so, not the way it feels. I was thinking the torque converter could be a possibility.
Merry Christmas to you.

 

[TCDiesel]

Thump yes It has a crush sleeve That requires 3/4 Drive Impact.. If the pinion bearing was bad it clunks bad and I mean loud it sound like a gun shot, when foot on service brake and put into gear..What Trans? Did you see the parts they R/R? Tip always ask to see parts. Here's how things work at dealerships , Customer drive in Makes complaint , SR writes it down, tech gets what the SR wrote down puts truck on lift, checks DL , finds additional play in DL rotation..That must be it Tears it down to fines X .. In order to get to the Pinion bearing the entire Drive member must be removed to get to the pinion shaft ,after the shaft is removed it has no noticeable wear..Now the tech starts making unprofound claims that other damage found to SR which is passed on to customer to comfort them. Other Damage means what.. did the debris reach the outer hub bearings in addition? if debris found in the center section did it miraculously affect the center section only ? You should fill out your signature BC many member's require that before they will comment.

 

[Benito]

Thanks TCD. I have the 68. I saw the parts they replaced,(at least what they told me came from my truck). They replaced everything inside the axle other than the shafts,(again, just what they told me). The feeling I get is not really a loud bang more like the driveline and the engine are fighting each other that is why I was thinking more like the torque converter was the culprit. Almost like it is staying locked or releasing late.
Thanks for the info on the signature. Still learning the site. Not sure where I need to go for that yet:-laf

 

[TCDiesel]

Yep.. the 68rfe has the symptoms You have mentioned....Transengineer is the member you want to send a link to this post.. He will chime in.

 

[TCDiesel]

I sent transengineer a Pm and link to this thread... Believe Me He will have to route to Narrow it down.

 

[Benito]

Thanks again for your time and assistance.
Merry Christmas to you.

 

[transe]

You could have a tech ride with you (with a scan tool) and monitor the TCC state and TCC slip, to see what the PCM is commanding (typically, I believe it should go to unlock or partial lock when you tip out of the throttle), and also to see if the slip value matches the commanded state (to confirm that the TCC is actually doing what the PCM commands). During closed throttle decel, I'd expect a negative TCC slip value.

 

[Benito]

Thanks. I tried to get into the dealership before the holiday but they were booked out 3+ weeks. I am hoping to be able to get in within the next week or 2. Will see what they tell me.