Ram2500 Posi Fails !!

[Drop George]

My 21' Ram 2500 6.4L 2WD .411 RearEnd Posi Failed at 16K mi (in warranty). Any of you see such a problem/tendancy, or am I just "Cursed" ! Thanks, George D

 

[Travelin Ram]

Failed how?

Clutch? Bearing? Gears?

 

[Drop George]

Thanks, As it's in a service depatment, it's hard to get details. As the driver, I spotted a "hopping" and tire shake during cornering ONLY. Straight away was fine. No gear or driveline noise at ALL. I just assumed it must be the clutches packett or spider LSD "case" that is the failure mechanism. I could turn left or right, and observe/feel the tire hop while
s l o w l y rolling and actually walking next to the vehicle. (did have vehicle in drive with driver of course). Hope this helps. Let me know what you think....

 

[Daw14]

Sounds like it needed some friction modifier added to the lube. Are you going to upgrade to a tru-trac ? If I recall correctly there was a bunch of trucks that left the factory with their differentials short of gear oil.

 

[Travelin Ram]

Locking the clutches is not a common failure I’ve heard of. Usually just chattering or groaning.

16k miles there’s no reason to believe an additive will fix it; it’s not like someone changing the lube and forgetting that yesterday.

Be persistent and require detailed information from the service department. They owe you that, even if it is a warranty repair. It’s still YOUR truck.

 

[Drop George]

Thanks Guys! Any other input a member has would be appreciated. I will bird-dog this.

 

[Riccochet]

Locking the clutches is not a common failure I’ve heard of. Usually just chattering or groaning.

16k miles there’s no reason to believe an additive will fix it; it’s not like someone changing the lube and forgetting that yesterday.

Be persistent and require detailed information from the service department. They owe you that, even if it is a warranty repair. It’s still YOUR truck.

True. But draining and filling the diff with fresh gear oil and friction modifier won't hurt either. Hell, just adding some friction modifier might quiet it down. Some LSD's require more than others.

 

[2020PW]

2500 doesn’t have clutch packs, it has helical gear assembly in all HD’s. Doesn’t require friction modifier as the 1500.

 

[Travelin Ram]

2500 doesn’t have clutch packs, it has helical gear assembly in all HD’s. Doesn’t require friction modifier as the 1500.

That used to be true, -and I’ve said it myself- however a few years back I was corrected and found out HD trucks had gone to clutch LSD. More or less about the introduction of gen 5 IIRC.

(Not true of the PW, but that’s not relevant for the OP)

 

[2020PW]

That used to be true, -and I’ve said it myself- however a few years back I was corrected and found out HD trucks had gone to clutch LSD. More or less about the introduction of gen 5 IIRC.

(Not true of the PW, but that’s not relevant for the OP)

No

They are made by AAM,

 

[Drop George]

Geo Here, THANKS!
So I understand, I've got a .411 RearEnd (2021 6.4L).
What's your best guess on it's type? (don't think it's "Trac-Rite").
Funny, with all the DIY Automotve work I've done (OBDII/Can bus, blah, blah,)
I've never had to worry about this #$$%....

 

[Travelin Ram]

You will find a clue if you read page 366 of your manual. Especially if you compare the fluid recommendations to earlier years.

Or you could go to the shop and look at it while it’s apart. Or speak to the dealership parts staff.

Just look at the document someone is promoting that illustrates no application to your 2021 HD.

There are resources in other forums, and I’m pretty sure posting a link here will get a post moderated.

Digital arguments over things that are easily examined in the real world are just not a good use of time, so I’ll move along and comment no further.

 

[1 MEAN66]

In writing would be best. Then there should be no future ( that's not what we said) issues.

 

[HEMIMANN]

Better double check - word was axles were changed from AAM to another vendor, maybe back to Dana which they used to use.

AAM axles were trouble-free. I got one on my 2017 2500 4x4. Also is all gear torsen anti-spin (different wording than limited slip). Word also was new axles were back to cheaper clutch pack limited slip - not LOCKING like all gear torsen. Look at the axle casting for the manufacturer's stamp.

The change was reportedly made as a cost reduction by FCA (Fiat). Higher profit. They're milking Ram to death and didn't reinvest for years.

 

[Drop George]

Ram2500 Posi Fails​

My update:

After several “unnatural acts”, and armed with a set of shop manuals and a bad attitude (it's been almost 2 mo.) I finally sat with the shop foreman and argued every point. Even went to the service bay and was allowed to inspect the vehicle and reviewed everything with the tech. Was amazed that he had set all preloads & backlash on the American .411 11.5” TruTrac diff.

Thanks for all the input on this forum.
I'll "Live Happily Ever After" Now (I can dream can't I?)......

Drop George

 

[HEMIMANN]

Ram2500 Posi Fails​

My update:

After several “unnatural acts”, and armed with a set of shop manuals and a bad attitude (it's been almost 2 mo.) I finally sat with the shop foreman and argued every point. Even went to the service bay and was allowed to inspect the vehicle and reviewed everything with the tech. Was amazed that he had set all preloads & backlash on the American .411 11.5” TruTrac diff.

Thanks for all the input on this forum.
I'll "Live Happily Ever After" Now (I can dream can't I?)......

Drop George

Well, I'll be damned - you do have a anti-spin AAM torsen TracRite GT all gear axle. I thought they quit using these?

TracRite Differential Portfolio | American Axle & Manufacturing | Aftermarket OE Parts

AAM Aftermarket brand products provides an array of Locking or Limited Slip Differentials for those applications where traction enhancement is a must. The TracRite® Series of limited slip a

www.demandaam.com

 

[Drop George]

Had a Friend (at a Chryser shop) look up my VIN. He old me it was "AAM 11.5 Truetrac" You got me questioning myself now.. It DOES have helical gears (no clutch plates) it IS a .411 11.5" Limited Slip. Honestly, I haven't research the subtleties between the two.

 

[HEMIMANN]

Had a Friend (at a Chryser shop) look up my VIN. He old me it was "AAM 11.5 Truetrac" You got me questioning myself now.. It DOES have helical gears (no clutch plates) it IS a .411 11.5" Limited Slip. Honestly, I haven't research the subtleties between the two.

TrueTrac is Eaton, not AAM. AAM is TracRite

https://www.eaton.com/us/en-us/catalog/differentials/eaton-detroit-truetrac-differential.html

 

[Drop George]

OOPs, and to think i JUST downloaded the PDF from AAM telling me that!
You should see me try to speak right now..... Thx