Rear End Failure

[hbalek]

I'm wondering if this is some kind of alignment issue (or rather misalignment) of the drive shaft , diff mounts, etc, basically everything connected to the diff. Unless you won the worst lottery and got two terribly defective rear diffs I'm at a loss. Where the bearings screwed at all, which could/would cause such issues.

Misalignment of the driveshaft to the diff would cause vibrations, noise, premature failure, wear, etc

I specifically asked my service department to check my driveshaft after 2 failed PTU's and RDU's. They found nothing with that but said the RDU had the wrong gear ratio. Mine is driving great now after a 4-wheel alignment and proper gear ratio differential.

 

[musclecarman39]

My rear differential and transfer case/ptu were replaced back in early June at about 50,000 miles. The transfer case failed again just 3 months later. I think the differential is bad again too.

Just had my rear diff replaced again for a howling noise at 45 mph. My 21 has 35,000 miles on it. Only had 700 miles on the 1st rear diff replacement. Picked it up from the dealership, had a very bad vibration, jerking and "bucking". Took it back and now the transfer case is being replaced...wth

 

[cheetoduster]

I specifically asked my service department to check my driveshaft after 2 failed PTU's and RDU's. They found nothing with that but said the RDU had the wrong gear ratio. Mine is driving great now after a 4-wheel alignment and proper gear ratio differential.

They put a diff from a 2.3L Explorer in your ST because they didn't know the difference. Probably a good thing the two have different gear ratios, if they were the same the service dept probably would have sent you on your way with the smaller diff.

 

[enphor]

Just had my rear diff replaced again for a howling noise at 45 mph. My 21 has 35,000 miles on it. Only had 700 miles on the 1st rear diff replacement. Picked it up from the dealership, had a very bad vibration, jerking and "bucking". Took it back and now the transfer case is being replaced...wth

Maybe another case of them installing a diff type with the wrong "ratio". I can see that messing up the PTU, things not spinning at the right speeds when the vehicle mechanical and electrical systems expect them to be pushing things to the point of failure.

Mental note , if I ever need a new rear diff, give them the exact part number for the ST!

 

[musclecarman39]

Maybe another case of them installing a diff type with the wrong "ratio". I can see that messing up the PTU, things not spinning at the right speeds when the vehicle mechanical and electrical systems expect them to be pushing things to the point of failure.

Mental note , if I ever need a new rear diff, give them the exact part number for the ST!

That's what I was thinking too. I'm definitely going to have them check to make sure it's the correct rear diff.

 

[jwuonog]

I specifically asked my service department to check my driveshaft after 2 failed PTU's and RDU's. They found nothing with that but said the RDU had the wrong gear ratio. Mine is driving great now after a 4-wheel alignment and proper gear ratio differential.

Glad to hear you're back up and running. What dealership did you go to? Do you have any mods?

 

[hbalek]

Glad to hear you're back up and running. What dealership did you go to? Do you have any mods?

I have no mods at all and I went to Sheehy Ford in Gaithersburg, where I bought it 5 years ago.

 

[msokes9]

So after my screen issue I finally had resolved back in July, it’s back at Ford right now and informed that I need 2 rear axles replaced. I noticed for a while that there was a noticeable clicking noise coming from the rear end when I was braking and accelerating from a stop. I was putting it off for a while because of my work schedule but finally took it in yesterday to get it looked at. I have 11k miles on it at the moment.

 

[enphor]

All these rear diff stories, ugh.

I recently installed amsoil 75W-110 gear lube and Steeda Brace. I have the Steeda Bushings, Whoosh bolt, and JXB Bushing insert sitting on my bench ready to go when I have time. I'm hoping by securing up the rear diff will avoid future problems. It may be wishful thinking, only time will tell.

 

[cheetoduster]

So after my screen issue I finally had resolved back in July, it’s back at Ford right now and informed that I need 2 rear axles replaced. I noticed for a while that there was a noticeable clicking noise coming from the rear end when I was braking and accelerating from a stop. I was putting it off for a while because of my work schedule but finally took it in yesterday to get it looked at. I have 11k miles on it at the moment.

That sounds more like the widely reported issue of axle hub noise caused by the axle splines. My '23 has started making that noise any time theres an accel/decel at low speeds or put the transmission in reverse. It's the same "ting" or "ping" noise you hear in the video.

 

[jwuonog]

That sounds more like the widely reported issue of axle hub noise caused by the axle splines. My '23 has started making that noise any time theres an accel/decel at low speeds or put the transmission in reverse. It's the same "ting" or "ping" noise you hear in the video.

Yup. I have this sound on mine too. I will get around to addressing it one day...

 

[musclecarman39]

Just had my rear diff replaced again for a howling noise at 45 mph. My 21 has 35,000 miles on it. Only had 700 miles on the 1st rear diff replacement. Picked it up from the dealership, had a very bad vibration, jerking and "bucking". Took it back and now the transfer case is being replaced...wth

Here's an update on my saga. So the original dealership replaced my transfer case and I still have the same issue, a vibration coming from the rear when I accelerate and if I keep pushing down on the accelerator it starts jerking and bucking. I can actually hear the rear ties break loose with each jerk. I asked them to make sure it was the correct rdu. They told me they can't pinpoint the issue so i took it home. Then a new problem started, a loud pop from the rear diff when starting to accelerate. So now I'm at another dealership and they found the bolts loose and actually sticking out on the transmission mount and the rear diff mounting points. Tightened those and that fixed the popping noise but still have the other 2 issues. They have now updated the pcm, awd module, transmission and transfer case strategies, made sure the rear wheel hubs are tight and no help. I've stressed to them that these 2 issues started immediately after the 2nd rear diff was installed. They pulled my receipts from the other dealership to verify the part numbers but that was end of day Friday. I'm getting really frustrated as I haven't driven my car hardly at all since the beginning of November.

 

[RusW1]

I am on my 3rd rear diff at 11700 miles. It all started with the howling noise at 65-73 mph. After my dealer replaced my rear diff the second time, along with all the other parts replaced, they contacted Ford Enginners. The second rear diff was for the 2.0 liter explorer, it was mislabeled and miscatalogued. Have your dealer verify part number on the unit not just the paperwork, and for peace of mind, do the calculation yourself to determine rear gear ratio, eg. driveshaft rotation count vs wheel rotation.

 

[musclecarman39]

I am on my 3rd rear diff at 11700 miles. It all started with the howling noise at 65-73 mph. After my dealer replaced my rear diff the second time, along with all the other parts replaced, they contacted Ford Enginners. The second rear diff was for the 2.0 liter explorer, it was mislabeled and miscatalogued. Have your dealer verify part number on the unit not just the paperwork, and for peace of mind, do the calculation yourself to determine rear gear ratio, eg. driveshaft rotation count vs wheel rotation.

I'll be talking to them again tomorrow and plan on showing them this post. I've told both dealerships it's possible the right part was ordered and the wrong one sent

 

[hbalek]

I am on my 3rd rear diff at 11700 miles. It all started with the howling noise at 65-73 mph. After my dealer replaced my rear diff the second time, along with all the other parts replaced, they contacted Ford Enginners. The second rear diff was for the 2.0 liter explorer, it was mislabeled and miscatalogued. Have your dealer verify part number on the unit not just the paperwork, and for peace of mind, do the calculation yourself to determine rear gear ratio, eg. driveshaft rotation count vs wheel rotation.

This exact thing happened to me. The wrong differential was installed and now since they put the correct one, the shuddering, grinding is gone. So in the past year, I've had 2 transfer cases and 2 differentials installed.

 

[GearHead_1]

As odd as it sounds. It could have been the wrong ratio. I believe the 2.3's all had the same 3.58 rear end as the 3.0 L ST's. That said, if I'm not mistaken the Platinum with a 3.0 L engine came with a 3.31 rear end, it would bolt right in, but if you have a 4WD, I would think it would buck like a bronco on a dry paved road and would definitely cause issues with the electronics (2WD or 4WD) as well as the transfer case on a 4WD.

 

[musclecarman39]

As odd as it sounds. It could have been the wrong ratio. I believe the 2.3's all had the same 3.58 rear end as the ST's. That said, if I'm not mistaken the Platinum with a 3.0 liter engine came with a 3.31 rear end, it would bolt right in, but I would think it would buck like a bronco on a dry paved road and would definitely cause issues with the electronics as well as the transfer case.

That's what I'm thinking because it does buck like a bronco. I'm going to the dealership again tomorrow and hopefully that's the conclusion they come to before I get there

 

[Cruising68]

That's what I'm thinking because it does buck like a bronco. I'm going to the dealership again tomorrow and hopefully that's the conclusion they come to before I get there

Bucking would be a good symptom of the wrong ratio. Bet it’s confusing the hell out of the computers


Sent from my iPad using Tapatalk

 

[musclecarman39]

To the guys that have had the wrong rear diff installed, what was the part number of the correct one that was installed? I'm getting conflicting part numbers from different dealerships? I'm being told S604D by 2 dealerships and S602D by 2 others. The S602D is currently in my ST and that's when the vibrations and bucking started.

 

[cheetoduster]

To the guys that have had the wrong rear diff installed, what was the part number of the correct one that was installed? I'm getting conflicting part numbers from different dealerships? I'm being told S604D by 2 dealerships and S602D by 2 others. The S602D is currently in my ST and that's when the vibrations and bucking started.

I thought the diffs in the 2.3 vs the 3.0 models were different ratios, but according to this they're the same. The difference is between the diff in the King Ranch/Platinum (3.31) vs the ST (3.58).

https://www.vdm.ford.com/content/da...owing/pdf/2024-Ford-Explorer-Towing-Guide.pdf

It's a small difference but enough to cause the vibrations/bucking. It looks like every Ford parts site uses the same specs no matter where you look, and they all say both part numbers are compatible with all models, so it's really confusing. But that's my guess, the S602D is for the King Ranch/Platinum.