Rear end locked up

[dkelly3103]

So I was driving 55-60mph on my way to work when I started hearing a whining sound when letting off the throttle and coasting, fast forward a couple miles and I hear a banging under the truck and the engine just revved and would not accelerate anymore, and the tires locked up. Got over to the side of the road and found a mess of broken parts under the truck. The driveshaft was about 100ft behind me in the middle of the road, the transfer case is cracked and missing a large chunk of the case on the passenger side, and the differential is locked up 100% as well as the pinion bearing completely destroyed and the pinion nut/flange ripped off and still attached the to the driveshaft. My theory is the differential locked up, broke the ujoints and threw off the driveshaft and cracked the transfer case in the process of the driveshaft banging around underneath. What I don’t understand is how the differential locked within a few miles of making noise. It does have 190k on it but I just changed the fluid in it probably 2000 miles ago and the old fluid that came out wasn’t terrible and there wasn’t a ton of metal shavings on the magnet. Any ideas on what could have happened and how I should proceed? Would I be better off looking for used or reman parts?

 

[dkelly3103]

 

[dkelly3103]

 

[crash68]

OUCH!
2010 I think is the last year that rear end was used before switching to the ZF version.
I'd search on www car-part.com to see what's available.

 

[Wild one]

View attachment 491699

Do you know if your truck was one of the early trucks that had the pinion nut recall,and if it was,did it ever go in for the recall.Looks almost like the pinion nut backed off,and that could cause alot of your issues. You have the earlier AAM diff,but the later ZF diff does bolt in,the only real differances are where the ABS sensors are located,on the early diffs they are on the front side of the axle tubes,and on the later ZF diffs they are on the back of the axle tube. You'll have to swap your backing plates onto the ZF diff,and grind a small notch into the axles flange so your ABS sensors will bolt back up. I swapped my ZF diff for the AAM diff several years ago,and other then the ABS sensor issue it was a direct bolt-in.

 

[Jeepwalker]

Looks almost like the pinion nut backed off.....

That's what it looks like to me. Can you see threads on the end of the pinion? If you can, the nut vibrated off.

Either way its a bummer. Open up the rear diff to see what it looks like. Inspect the axles for wear too, and then make an assessment. Probably best to rebuild the rear end if the axles are good, that way you end up with a new diff rather than a used one with unknown miles or condition. But I've replaced whole rear ends with used and personally never had a problem. Replace the transfer case or open it up and have a look. They're easy to rebuld actually, depending on the damage. Of course if you need it up and running right away and money is tight, then probably go with used stuff.

Glad you or nobody else got hurt...

 

[dkelly3103]

That's what it looks like to me. Can you see threads on the end of the pinion? If you can, the nut vibrated off.

Either way its a bummer. Open up the rear diff to see what it looks like. Inspect the axles for wear too, and then make an assessment. Probably best to rebuild the rear end if the axles are good, that way you end up with a new diff rather than a used one with unknown miles or condition. But I've replaced whole rear ends with used and personally never had a problem. Replace the transfer case or open it up and have a look. They're easy to rebuld actually, depending on the damage. Of course if you need it up and running right away and money is tight, then probably go with used stuff.

Glad you or nobody else got hurt...

I was wondering that as well, both the threads on the pinion and the nut look fine too. Thinking on it now that acually makes more sense. I was originally wondering how the driveshaft would have twisted off and gotten so damaged if it just came unbolted from the pinion but I guess that explains why the ujoints didn’t snap on the pinion side, just the slip yoke side where it was still trying to spin from. Would the pinion sliding back into the differential when it came unbolted cause it to lock up too?

 

[dkelly3103]

Do you know if your truck was one of the early trucks that had the pinion nut recall,and if it was,did it ever go in for the recall.Looks almost like the pinion nut backed off,and that could cause alot of your issues. You have the earlier AAM diff,but the later ZF diff does bolt in,the only real differances are where the ABS sensors are located,on the early diffs they are on the front side of the axle tubes,and on the later ZF diffs they are on the back of the axle tube. You'll have to swap your backing plates onto the ZF diff,and grind a small notch into the axles flange so your ABS sensors will bolt back up. I swapped my ZF diff for the AAM diff several years ago,and other then the ABS sensor issue it was a direct bolt-in.

If I get a complete diff with the abs sensors, calipers etc will the abs sensors on the ZF style plug right in or will I still have to do as you explained? I found one off of a 2016 with less than 150k miles for $300 which I thought was a great deal.

 

[Jeepwalker]

I don't know about the sensor, but obviously make sure the ratio is the same as your original...

Back to your driveshaft, the moment it became unhooked, it was spinning rapidly. Then it flogged around under your truck for a second or so until the front got thrown out of the transfer case. I'm sure it was a violent event.

 

[dkelly3103]

I don't know about the sensor, but obviously make sure the ratio is the same as your original...

Back to your driveshaft, the moment it became unhooked, it was spinning rapidly. Then it flogged around under your truck for a second or so until the front got thrown out of the transfer case. I'm sure it was a violent event.

Yep both 3:55.

It actually wasn’t as violent as you would think. I only heard some noise for maybe 2 seconds then the it was silent as the driveshaft had already fallen out. I was going around 60 so I’m sure with the speed it was rotating it didn’t take long for it to bust out of slip yoke flange.

 

[Jeepwalker]

I'd have loved to see that caught on camera!

Hey, if you do replace the transfer case with a used one, consider buying a new Mopar splined collar that connects the xfer case to the tranny. At 190k a new coupler might help tighten up the driveline 'freeplay' a little.

 

[dkelly3103]

I'd have loved to see that caught on camera!

Hey, if you do replace the transfer case with a used one, consider buying a new Mopar splined collar that connects the xfer case to the tranny. At 190k a new coupler might help tighten up the driveline 'freeplay' a little.

I will definitely look into that. Thanks for telling me about thay, I don’t have the transfer case off yet so I didn’t know there was one there.

 

[Jeepwalker]

Whoops! Don't bother. I just looked up the xfer case. The input gear has a female spline on the Ram xfer case. I probably should have looked before posting earlier.

Good luck on your swap-over project. Keep us up to speed on the project.

 

[dkelly3103]

Whoops! Don't bother. I just looked up the xfer case. The input gear has a female spline on the Ram xfer case. I probably should have looked before posting earlier.

Good luck on your swap-over project. Keep us up to speed on the project.

Will do! Going to pick up the diff tomorrow then having the driveshaft and transfer case mailed to me. Hoping to have it done by the end of this week if they come in in time.

 

[dkelly3103]

So found some more info on the pinion nut recall mentioned earlier, if I’m not the original owner and considering the truck has 193k miles is there still anything that can be done?

 

[dkelly3103]

 

[Jeepwalker]

You can check a chrylser website where you put in your vin. And you should be able to see what warranty work was done on your truck and what hasn't. I forget the site ...perhaps google for it. I don't know the exact answer to your question but you might want to see if it was 'done' on your truck first.

 

[dkelly3103]

You can check a chrylser website where you put in your vin. And you should be able to see what warranty work was done on your truck and what hasn't. I forget the site ...perhaps google for it. I don't know the exact answer to your question but you might want to see if it was 'done' on your truck first.

Well just called the FIAT Recall center and the talked to took the vin number and said my truck is covered under the recall and that it will be taken care of free of charge if that was found to be the issue. Never dealt with sort of thing before so I’ll see how it goes when I have my truck towed there.

 

[Wild one]

If I get a complete diff with the abs sensors, calipers etc will the abs sensors on the ZF style plug right in or will I still have to do as you explained? I found one off of a 2016 with less than 150k miles for $300 which I thought was a great deal.

I think they use the same sensors,but whether you'll have enough wire length to move them to the back i'm not sure.I pulled the axles ,and unbolted the backing plates and just left them hooked up to the truck. 2 reasons for doing that was my brakes and e-brake assembly were still in mint shape,plus i was doing the diff swap by myself using a floor jack,and having the axles out,meant the diffs were alot lighter and easier to man handle by myself. It was a good time to replace the axle seals at the same time.

 

[Wild one]

Well just called the FIAT Recall center and the talked to took the vin number and said my truck is covered under the recall and that it will be taken care of free of charge if that was found to be the issue. Never dealt with sort of thing before so I’ll see how it goes when I have my truck towed there.

Awright,hopefully they take care of you.