Grinding Sound from Rear End During Low-speed Take-off

[20bigblue19ram]

I'm very interested in this discussion as well. My truck makes a grinding noise and I can feel vibration when I take a right at slow speeds as well. I took it to the dealership and they told me the problem was my electric power steering rack. They said there is a TSB on it, however they said mine was up to date. They ordered the part for me (back ordered for 4 weeks of course), and will install it once it gets there. I'm wondering now reading through this post if this will actually be the problem, or if I will still have the issue. Good thing for me is they were able to replicate it when they drove it.

 

[bpwj76]

I'm very interested in this discussion as well. My truck makes a grinding noise and I can feel vibration when I take a right at slow speeds as well. I took it to the dealership and they told me the problem was my electric power steering rack. They said there is a TSB on it, however they said mine was up to date. They ordered the part for me (back ordered for 4 weeks of course), and will install it once it gets there. I'm wondering now reading through this post if this will actually be the problem, or if I will still have the issue. Good thing for me is they were able to replicate it when they drove it.

Did you click on the link I posted at the beginning of this thread and watch the video of the noise mine makes?

 

[cj7]

So the parts didn't arrive until today. They are telling me now that they aren't replacing the whole axle assembly. Just the carrier bearings. The SA also said the tech told her that my Airlift 1000 airbags would normally alter my warranty. But I guess they are going to "look the other way". Has anyone else been told that airbags would "alter" their warranty?

So, where they lying the first time they told you what they were doing, or ignorant? I have like no patience for that sh-t.

Also, the tech has absolutely no say in what’s covered by the warranty. And “alter the warranty”? That is meaningless gibberish - god how I hate dealing with the FCA dealer service departments.

Good luck, friend - I’m afraid you might need it...

 

[bpwj76]

The normal SA was out sick and I got a call from someone filing in for her who said I was getting a complete axle assembly. When she came back and called me to tell me about the carrier bearings, I asked what the heck was actually being installed. She said the guy filling in for her was mistaken. Par for the course in my experience dealing with FCA service departments. Right hand doesn't know what the left hand is doing.

Good point about the tech not having any say in what's covered or not. That thought/opinion should have been kept to himself. Yeah, meaningless gibberish, LOL!

The SA also texted me this: "He (the tech) told me to let you know to be careful with whatever you are towing. There are lots of wear marks where it seems to be a heavy load binding down on the bearings. I told him to save it so we can show you."

Ok, what I am towing is well under the limits of the truck in payload, towing, and GCWR. I have Cat Scale tickets to prove it. So either the previous owner (I bought it with 15k miles) overloaded it or the truck can't actually handle what it was desinged for.

 

[cj7]

The normal SA was out sick and I got a call from someone filing in for her who said I was getting a complete axle assembly. When she came back and called me to tell me about the carrier bearings, I asked what the heck was actually being installed. She said the guy filling in for her was mistaken. Par for the course in my experience dealing with FCA service departments. Right hand doesn't know what the left hand is doing.

Good point about the tech not having any say in what's covered or not. That thought/opinion should have been kept to himself. Yeah, meaningless gibberish, LOL!

The SA also texted me this: "He (the tech) told me to let you know to be careful with whatever you are towing. There are lots of wear marks where it seems to be a heavy load binding down on the bearings. I told him to save it so we can show you."

Ok, what I am towing is well under the limits of the truck in payload, towing, and GCWR. I have Cat Scale tickets to prove it. So either the previous owner (I bought it with 15k miles) overloaded it or the truck can't actually handle what it was desinged for.

LoL....

It could be the previous owner, who knows. But yeah, I’m sure the tech has training in identifying the difference between bearing scar from overload vs defect vs lube failure vs improper install...

Definitely post a pic of what the “tech” thinks is heavy load binding!

 

[bpwj76]

LoL....

It could be the previous owner, who knows. But yeah, I’m sure the tech has training in identifying the difference between bearing scar from overload vs defect vs lube failure vs improper install...

Definitely post a pic of what the “tech” thinks is heavy load binding!

Man, this is pure gold. What you said about the difference between scars from overload vs defect vs lube failure vs improper install. I never would have thought of those things. I am going to bring that up when he tries to "show me what I did."

Thanks!!!

 

[bpwj76]

Picked it up just now. I asked him how he could tell the parts were damaged by "overloading" and not by improper installation, defect, or fluid breakdown. His reply was basically that in his 30 years of experience, the markings he saw on those bearings are from overloading. I still don't know how he can know that for sure unless he was witness to said overloading.

Anyway, he showed me the old parts and said the scoring or black marks on the rings should not be there. The gear in the first pic looked good. No damage that either one of us could see and he said there was nothing out of the ordinary in the fluid and the magnet at the bottom of the diff housing was clean. He said he had to change the diff fluid again and he made sure it was all the way full. No chance it was under-filled to cause the problem some others on here have noted with their diffs.

This seems to have resolved my issue. All I can do from this point is make sure I'm towing safely and within the limts and get that fluid changed every 30k miles.

 

[cj7]

Picked it up just now. I asked him how he could tell the parts were damaged by "overloading" and not by improper installation, defect, or fluid breakdown. His reply was basically that in his 30 years of experience, the markings he saw on those bearings are from overloading. I still don't know how he can know that for sure unless he was witness to said overloading.

Anyway, he showed me the old parts and said the scoring or black marks on the rings should not be there. The gear in the first pic looked good. No damage that either one of us could see and he said there was nothing out of the ordinary in the fluid and the magnet at the bottom of the diff housing was clean. He said he had to change the diff fluid again and he made sure it was all the way full. No chance it was under-filled to cause the problem some others on here have noted with their diffs.

This seems to have resolved my issue. All I can do from this point is make sure I'm towing safely and within the limts and get that fluid changed every 30k miles.

Thx for the follow-up. Before saying anything, one question to be sure: are the photos with the black marks showing the outer circumference of the outer race of the differential carrier bearings (Pic 2 blue arrows) ?




Seems like that is what they were saying was replaced.

Before I say that “tech” is more full of sh-t than a backed up toilet at a greasy burrito restaurant , I wanna be sure...

 

[Drivinfast247]

Thx for the follow-up. Before saying anything, one question to be sure: are the photos with the black marks showing the outer circumference of the outer race of the differential carrier bearings (Pic 2 blue arrows) ?

View attachment 104417
View attachment 104422

Seems like that is what they were saying was replaced.

Before I say that “tech” is more full of sh-t than a backed up toilet at a greasy burrito restaurant , I wanna be sure...

Sure looks like the outside of the outer race. Was it spinning in the housing?

 

[cj7]

OK, couldn’t hold my breath too long...

This is from Timken’s Bearing Damage Analysis Reference Guide, 2020.

It is possible the bearing outer ring rotated (slipped) inside the diff case, likely from housing (differential case) bearing seat machining issues. I would guess you would see more wear than the pic shows, but can’t be sure.



Also possible is bearing damage from the carrier bearing seat having a minor machining defect that causes a high spot (slightly out of round), where the diff case presses a little harder on the bearing outer race (aka outer ring) than everywhere else. This and housing machining issues are known causes of reduced bearing life.



Other possibility is inept bearing removal (likely the cause of the middle pic). Less likely, but possible, is inept bearing installation. Just guessing...

Unlikely to be truck loading or towing caused. You’d see that on the insides of the axle bearing, where load is carried and metal moves against metal, not diff carrier bearing, and certainly not on the outside of the bearing. The bearing part in those two pics is pressed into the diff case, not supposed to move, and thus not a wear area.

You should be good for a while. It’s possible the removal and installation of a new bearing reduced the problem, and you’re good to go.

If it happens again, ask that another tech inspect the diff case carrier bearing seats...

 

[bpwj76]

Yes, the marks were on the outer circumference.

I will try to remember your recommendation about a different tech inspecting the diff case carrier bearing seats IF it happens again. I'm hoping the new parts fixed the problem for good.

There must be some sort of dealership service department book of BS to say to customers to calm their fears. In said book you will find this quote "Reassure the customer by telling them you have 30+ years of experience." I have heard this line several times before.

 

[cj7]

Yes, the marks were on the outer circumference.

I will try to remember your recommendation about a different tech inspecting the diff case carrier bearing seats IF it happens again. I'm hoping the new parts fixed the problem for good.

There must be some sort of dealership service department book of BS to say to customers to calm their fears. In said book you will find this quote "Reassure the customer by telling them you have 30+ years of experience." I have heard this line several times before.

LoL. I’m all for valuing experience. Just when it’s used out of false pride...

BTW, have you heard the story about the retired old Navy steamship master?

One day, an Navy steamer pulls into port, albeit slower than it should. Upon tying up, the Captain calls 2nd Level Support for a problem his crew has not been able to resolve. The maintenance chief tells the captain that his is one of the oldest steam plants in the fleet, and no one is left who knows steam better than Charlie, who retired and now does a bit of “consulting”. Cap says, hire him for this job, as we’ve been racking our collective brains this whole cruise.

So the Chief gets Charlie to take the task. Next day, an older guy pulls up in an even older pickup, carrying an even older wooden toolbox. Cap suppresses his doubts, and shows him around the ship personally. All the Captain gets out of Charlie, as he explains the problem and what they’ve done so far, is “ Uh-huh”. “Uh-huh”. “Uhh-huhh”.

As Cap finishes the walkthru, he asks Charlie if he can help.
”Uh-huh”.
The Captain steps aside and says “The ship is yours”.

Charlie walks purposefully a good ways, stops, seems to carefully study the maze of pipework and gauges before him, standing quietly.

”Ah-hah”.

Charlie reaches down and pulls out a knarly looking, heavily weathered and slightly rusty 2# hammer, and in one fluid, sure motion, strikes the flange of a valve.

”Pinggggg”

A gurguling sound emenates from deep in the bowels of the ship, a rumbling, then right at the area of the struck valve, a “cloingg” , “clunk”, “thunk”, “hiss”, and finally “whoosh”, and with that, the gauges all start to climb back into the green arcs, and the ship gives off a happy vibe as the machinery settles into a now regular, steady pitch.

The Captain is quiet,slightly stunned, somewhat amazed, as he realizes that the ship is now restored. Cap watches Charlie slip the sledge into the toolbox, handling the heavy tool as if it where and extension of himself, and pickup a invoice pad. The kind that had the carbon paper between each sheet. Charlie takes a pencil from somewhere, scribbles, rips the top copy off, folds it in half, and hands it to the Captain as he starts up the stairs topside.

As they approach the deck, the Captain unfolds the invoice, and sees this:
USN 12345, Steamfitting consult and maintenance, $5,001.00

Well, in this day and age, that’s a fair chunk of change, as so the Captain asks how that work could possibly justify such a bill.

Charlie lifts his head, speaking slowly but for the first time, in words, and says “One dollar for one swing of the hammer. Five thousand dollars for knowing where the hammer should strike.”

 

[y7eah]

I was having this same issue, and tow a 6k Travel Trailer. I had it in at the last oil change and they said it was "Normal" for the Limited Slip Dif. I had a 2019 with about 16k miles. I feel like it's suspicious that others also tow a travel trailer and are having the same issue. I ended up trading it in yesterday rather than starting a battle to get it fixed. My truck was 3.21 (not ideal for towing obviously) but towed fine from a power standpoint. I could feel a slight vibration and sounds like ABS kicking in from the rear, at times also felt like a loss of power when trying to pull out intro traffic.

 

[afonda]

I am having the same issues with my 2020 2500 Power Wagon at only 16k miles. I just bought it like 3 weeks ago. I immediately noticed the sensation from the rear. Sort of like the brakes were rubbing but only at very low speed (0 to 3 mph) and worse when turning. Dealer has the truck for the last week and 1/2. They are replacing the entire carrier unit in the rear diff. After reading this thread and others, it seems like the friction plates and friction modifier are the issue. Logic dictates that the plates are wearing prematurely. Maybe they are not putting the right oil in at the original build?

Add more friction modifier??? Problem is... too much friction modifier would seem to reduce the LS capability and turn it more into an open diff. Just a thought.

 

[cj7]

I am having the same issues with my 2020 2500 Power Wagon at only 16k miles. I just bought it like 3 weeks ago. I immediately noticed the sensation from the rear. Sort of like the brakes were rubbing but only at very low speed (0 to 3 mph) and worse when turning. Dealer has the truck for the last week and 1/2. They are replacing the entire carrier unit in the rear diff. After reading this thread and others, it seems like the friction plates and friction modifier are the issue. Logic dictates that the plates are wearing prematurely. Maybe they are not putting the right oil in at the original build?

Add more friction modifier??? Problem is... too much friction modifier would seem to reduce the LS capability and turn it more into an open diff. Just a thought.

my issue cropped up about the same time. Was the oil, and completely fixed when refilled with good synthetic and proper amount of modifier.

the modifier increases static friction, and reduces shear friction. The effect is the plates stick together better until the torque exceeds shear strength, and then slide past each other easier. Kinda like making it an on-off switch, rather than gradual release or grab.

not enough modifier makes them slip too soon, and grind while slipping.

 

[Mountain Whiskey]

Yes, the marks were on the outer circumference.

I will try to remember your recommendation about a different tech inspecting the diff case carrier bearing seats IF it happens again. I'm hoping the new parts fixed the problem for good.

There must be some sort of dealership service department book of BS to say to customers to calm their fears. In said book you will find this quote "Reassure the customer by telling them you have 30+ years of experience." I have heard this line several times before.

Yes, the 30+ years of experience line is especially frustrating when they are about 35 years old....

 

[afonda]

Well, they want to replace the whole carrier on my rear diff. I am trusting they will add the right amount of friction modifier. What else can I do besides stand over their shoulder which they won't allow anyway.

 

[Rjmlax21]

Also experiencing the same thing on my 2019 RAM Limited 1500. I had the rack and pinion replaced at about 17k due to a stuttering and grinding sound in the column. I ended up finding a recall here on 5th gen ram forums so they replaced it free of charge.

Fast forward now to 44k and I now have a grinding and rubbing noise on slow speed turns that sounds concerning. It’s gotten significantly worse. It honestly sounds like metal and rubber grinding/rubbing together creating this sound on turns only. Took it two two separate techs and had to drive with them to replicate the issue/sound. They did the differential back in January and the initial tech said the noise would still be there, but only momentarily as the fluid had to work its way through the differential.

I’m about 4000 miles since that fluid change and the noise has gotten progressively worse and worse and I am now taking it back in. The new tech said he hast to take the whole rear end apart to figure out what’s going on because he can definitely hear it and he said that is not the differential.

 

[theblet]

Also experiencing the same thing on my 2019 RAM Limited 1500. I had the rack and pinion replaced at about 17k due to a stuttering and grinding sound in the column. I ended up finding a recall here on 5th gen ram forums so they replaced it free of charge.

Fast forward now to 44k and I now have a grinding and rubbing noise on slow speed turns that sounds concerning. It’s gotten significantly worse. It honestly sounds like metal and rubber grinding/rubbing together creating this sound on turns only. Took it two two separate techs and had to drive with them to replicate the issue/sound. They did the differential back in January and the initial tech said the noise would still be there, but only momentarily as the fluid had to work its way through the differential.

I’m about 4000 miles since that fluid change and the noise has gotten progressively worse and worse and I am now taking it back in. The new tech said he hast to take the whole rear end apart to figure out what’s going on because he can definitely hear it and he said that is not the differential.

There’s a TSB for this. I had the same problem. They installed the software and it fixed it.

 

[theblet]

See attached