21 FX4 Rear Diff Whine Solutions?

[xplorre]

Just when I thought my truck was indestructible...

I have a whine that's been steadily growing louder coming from the rear. I chocked it up to the new Cooper XLT 33s i recently got, but it sounds to be a combination of that and the rear diff. Today I drained and filled with about 50% 80-90 conventional and the rest Lucas (since that's a trick Ive done successfully on my old car). The noise has diminished a bit but it's certainly still there. What I drained didnt have any discernible chunks in it, just the fine fillings you'd expect, though maybe slightly more than the last time I drained and filled.

107k of highway miles commuting to work.

Looking for options here. I referenced a thread with the part numbers for the work (https://www.ranger5g.com/forum/threads/ranger-rear-end-problems.22547/) but don't know if there's anything else I should try first. I'm willing to do basically any mechanical work myself, but driveline stuff is too specialized for me to risk messing up. If I could get a crated rear diff, I'd happily slap that thing in myself.

Looking for options: 1. Try some other combination of snake oil and wait for the truck to grenade and strand me in the middle of nowhere on my way to work. 2. Order the parts in that thread and pay a local driveline shop to install. 3. Buy a crated diff which I can't seem to find a price on.

Thoughts?

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[Stevedbvik1]

Go on car-part.com and search for a low mileage used rear axle. There’s plenty out there and quite reasonable. Swap your stuff over.

 

[k1w1t1m]

You might find someone on here that might do a wheel trade for a couple of hours to prove or disprove tire noise.

 

[xplorre]

You might find someone on here that might do a wheel trade for a couple of hours to prove or disprove tire noise.

Great idea, however I just swapped on my old set of wheels and tires that I had in the backyard, and the noise is very much still there

 

[xplorre]

This is the exploded diagram I just got from my parts guy at Ford. Apparently the items with little circle attached to them come as a group, and the ring and pinion come as a group as well.

Curious to hear from anybody who has spent some time inside the diff to let me know what I should expect to find before I go tearing it apart.

 

[xplorre]

Just got a quote from a reputable local shop, they will do new complete guts for the differential for $1400 to $1,500

 

[Indy650]

Just when I thought my truck was indestructible...

I have a whine that's been steadily growing louder coming from the rear. I chocked it up to the new Cooper XLT 33s i recently got, but it sounds to be a combination of that and the rear diff. Today I drained and filled with about 50% 80-90 conventional and the rest Lucas (since that's a trick Ive done successfully on my old car). The noise has diminished a bit but it's certainly still there. What I drained didnt have any discernible chunks in it, just the fine fillings you'd expect, though maybe slightly more than the last time I drained and filled.

107k of highway miles commuting to work.

Looking for options here. I referenced a thread with the part numbers for the work (https://www.ranger5g.com/forum/threads/ranger-rear-end-problems.22547/) but don't know if there's anything else I should try first. I'm willing to do basically any mechanical work myself, but driveline stuff is too specialized for me to risk messing up. If I could get a crated rear diff, I'd happily slap that thing in myself.

Looking for options: 1. Try some other combination of snake oil and wait for the truck to grenade and strand me in the middle of nowhere on my way to work. 2. Order the parts in that thread and pay a local driveline shop to install. 3. Buy a crated diff which I can't seem to find a price on.

Thoughts?

I just spent 5 grand replacing the entire rear end and drive shaft in my 2019. Mechanic said it's common with the Rangers. Count yourself lucky mine went out at 73000 and it's mostly easy highway miles. I found low mileage complete axles on ebay for way cheaper than what I paid but with my disability I can't wrench anymore so 5G loss it is. I'm not very happy with this truck after losing a rear end after 70k but the rest of the truck has been good for the most part. Also they claim my 32" Mickey Thompsons didn't help but since when can't you put a set of 32s on a light truck?

 

[xplorre]

I just spent 5 grand replacing the entire rear end and drive shaft in my 2019. Mechanic said it's common with the Rangers. Count yourself lucky mine went out at 73000 and it's mostly easy highway miles. I found low mileage complete axles on ebay for way cheaper than what I paid but with my disability I can't wrench anymore so 5G loss it is. I'm not very happy with this truck after losing a rear end after 70k but the rest of the truck has been good for the most part. Also they claim my 32" Mickey Thompsons didn't help but since when can't you put a set of 32s on a light truck?

Oof, well thanks for the heads up. Did the diff totally grenade itself? Is that why all of that needed replacing?

 

[xplorre]

So here's a heads up. I just picked up my truck from a diff shop nearby, 1,500 bucks to replace the ring and pinion and rebuild the carrier with Yukon parts. Pinion bearings were shot and carrier bearings were on their way out. I had them do the ring and pinion just because they were in there.

Here's what I wanted to pass on, they said that their recommendation for anybody with a d44, especially if you do a lot of highway driving, is to change out the diff fluid every 10 to 15,000 mi.

I plan on doing that from now on

For reference, my truck has 33s and the OME lift

 

[2023 Ranger]

Just when I thought my truck was indestructible...

I have a whine that's been steadily growing louder coming from the rear. I chocked it up to the new Cooper XLT 33s i recently got, but it sounds to be a combination of that and the rear diff. Today I drained and filled with about 50% 80-90 conventional and the rest Lucas (since that's a trick Ive done successfully on my old car). The noise has diminished a bit but it's certainly still there. What I drained didnt have any discernible chunks in it, just the fine fillings you'd expect, though maybe slightly more than the last time I drained and filled.

107k of highway miles commuting to work.

Looking for options here. I referenced a thread with the part numbers for the work (https://www.ranger5g.com/forum/threads/ranger-rear-end-problems.22547/) but don't know if there's anything else I should try first. I'm willing to do basically any mechanical work myself, but driveline stuff is too specialized for me to risk messing up. If I could get a crated rear diff, I'd happily slap that thing in myself.

Looking for options: 1. Try some other combination of snake oil and wait for the truck to grenade and strand me in the middle of nowhere on my way to work. 2. Order the parts in that thread and pay a local driveline shop to install. 3. Buy a crated diff which I can't seem to find a price on.

Thoughts?

I have a 23' with only 27,000 miles and have noticed a whine from the rear end as well. Mine only does it when I'm going around 40 mph or faster and only when I let off the gas and it's not under load. When I press the gas the whine goes away. Is this what yours was doing?

 

[Av8or1]

This is the exploded diagram I just got from my parts guy at Ford. Apparently the items with little circle attached to them come as a group, and the ring and pinion come as a group as well.

Curious to hear from anybody who has spent some time inside the diff to let me know what I should expect to find before I go tearing it apart.

So the good news is that our Ranger has probably the most common rear axle on the planet. A Dana 44 is used in most every vehicle of this size. If you want to dig around YouTube I'm sure there are plenty of good tutorials on rebuilding this diff. If you wanted to be fancy now would be a good time to change the diff to a different style if you were interested, i.e limited slip or air locker etc.

The bad news is with a drain plug like that, I would guess you need to get this addressed ASAP and it is currently in-process of grenading. Some metal shaving are normal, but usually just a very very thin surface amount on the plug. That looks to be pretty excessive, especially if you've already changed the fluid.

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