Rear differential whine

[Boostedbus]

Well I finally decided to take my 17 EL XLT in to the dealership for rear differential tip and moan whine between 50-60 mph. I tried to get them to install a whole new center section but was told Ford doesn’t even sell whole center section assemblies anymore. It has to be rebuilt by a technician piece by piece. I’m praying they get it set up right. I’ve had the noise since it was new and finally decided I wasn’t going to live with it anymore. I only have 13,000 miles on it and have a 100,000 mile/7 year warranty. I also told the service manager to have a set of lug nuts ready if they kill mine with a air gun. I’ll post results when I get it back.

 

[cmiles97]

That doesn't inspire confidence but you are covered against future problems other than the pain of having to leave it at the dealership.

I'm concerned that there is no part to replace a problem item.

 

[Black]

This is pretty much common place in regard to repairing a differential.
Sure folks will just swap out a whole differential on their own from a junkyard or something.
But a straight swap for a whole new unit vs a rebuild is very uncommon.

The housing is not the issue unless somehow it was cast wrong and won’t seal properly allowing water in.

 

[Boostedbus]

Well I got my Expy back from the dealer and the whine is still there but is a little better. The whining noise comes in only at 55 mph now and speeds above or below it’s non existent. So I’ve decided to live with it for the time being unless it starts getting worse. I can’t drive 55 anyway. They also didn’t ruin my lugs so that was a plus.

 

[Boostedbus]

Oh I forgot to mention this, on my way home from the dealer I have a very steep hill with a hairpin turn in it that I’ve got to go up. So I thought that was the perfect place to see if my limited slip traction still worked fine. I got on the hill and turned traction control off and spanked down on the throttle , and to my surprise it wheel hopped and fishtailed and then I immediately felt braking kick in like traction control. I then noticed another light illuminate on the dash right next to the traction control off light that I’m guessing was ride stability control light. This is the first time that I’ve seen this light or had it kick in. I have launched it on only 2 other occasions from a dead stop with traction control off only to find it would fishtail and spin maybe 20 feet or so before hooking up, but never kicked in the RSC. I’m guessing the uphill while turning and wheel hopping along with fishtailing was why it kicked in. I now know that at least that system works also.

 

[Black]

Did they rebuild it with new parts or did they reuse the ring and pinion??

Swap out your fluid for Amsoil Severe Gear Oil and use Ford friction modifier.
You may loose the shine completely.

My Explorer had very noticeable whine. I swapped fluid granted it was a bit milky that I drained. But with the Amsoil the rear was super smooth and quiet. A couple quarts and friction modifier will Run you about $30 and the rear is easy to swap fluid.
Worth the shot to get rid of the whine and better gear oil.

 

[Boostedbus]

Did they rebuild it with new parts or did they reuse the ring and pinion??

Swap out your fluid for Amsoil Severe Gear Oil and use Ford friction modifier.
You may loose the shine completely.

My Explorer had very noticeable whine. I swapped fluid granted it was a bit milky that I drained. But with the Amsoil the rear was super smooth and quiet. A couple quarts and friction modifier will Run you about $30 and the rear is easy to swap fluid.
Worth the shot to get rid of the whine and better gear oil.

According to the invoice they did. The friction modifier is to help the clutches slip while turning a corner. I may try a better gear oil like you say.

 

[bobmbx]

View attachment 28882
According to the invoice they did. The friction modifier is to help the clutches slip while turning a corner. I may try a better gear oil like you say.

Don't. Just use what the owners manual says to use.

 

[Black]

View attachment 28882
According to the invoice they did. The friction modifier is to help the clutches slip while turning a corner. I may try a better gear oil like you say.

Correct on the friction modifier.
Amsoil initially, still kind of does, said you don’t need to add friction modifier to their gear oil.
Some vehicles still exhibit chatter so adding a $7 bottle of friction modifier is well worth it. Amsoil makes their own called SlipLoc but no one carries it locally and Ford always has theirs in stock. So I have never used it.

Amsoil is far superior to Motorcraft gear oil.
Every differential I have gets their Severe gear oil in the proper weight.
All run smooth as a sewing machine.

 

[99WhiteC5Coupe]

Did they rebuild it with new parts or did they reuse the ring and pinion??

Swap out your fluid for Amsoil Severe Gear Oil and use Ford friction modifier.
You may loose the shine completely.

My Explorer had very noticeable whine. I swapped fluid granted it was a bit milky that I drained. But with the Amsoil the rear was super smooth and quiet. A couple quarts and friction modifier will Run you about $30 and the rear is easy to swap fluid.
Worth the shot to get rid of the whine and better gear oil.

I have a 2015 Expediton Limited 4x4 - purchased new.

Any tips on the changing rear differential fluid, other than the fluid use?

Thank you.

 

[TobyU]

I can’t drive 55 anyway.

One of my favorite songs!!

 

[TobyU]

Did they rebuild it with new parts or did they reuse the ring and pinion??

Swap out your fluid for Amsoil Severe Gear Oil and use Ford friction modifier.
You may loose the shine completely.

My Explorer had very noticeable whine. I swapped fluid granted it was a bit milky that I drained. But with the Amsoil the rear was super smooth and quiet. A couple quarts and friction modifier will Run you about $30 and the rear is easy to swap fluid.
Worth the shot to get rid of the whine and better gear oil.

Amsoil does make great products but for gear noises Shaeffer's might even be better.

 

[Black]

I have a 2015 Expediton Limited 4x4 - purchased new.

Any tips on the changing rear differential fluid, other than the fluid use?

Thank you.

Easy job.

Undo the fill plug at the top then the drain plug at the bottom. Reinstall drain plug. Buy the hand pump that fits the larger top amsoil bottles. The Ford friction modifier bottle is small enough to just put up to the fill hole and squeeze.

Factory uses red thread sealer on the plugs. I was unaware of this and buggered up the plug trying to get them off.
Heat them up with a torch and they will come right off and you won’t need to replace the plugs like I did. Though they are cheap if you just want to buy new ones in case.


You can see where I buggered that one up.
May as well do the front too. Only rub is you need to pump the fluid out of the front diff.
And don’t forget the transfer case but DO NOT use anything but the proper Transfer Case fluid from Ford. None of the generic multicase fluids, none!
Those plugs came out easy as pie since the TC case housing is aluminum.

 

[1955moose]

Well I got a question for all you guys? This is the first post I can remember about gear whine in a fourth edition. Why are you padding down a problem with slippery oil and friction modifier? Sounds like our op needs to pursue the original problem from Ford. Something was shimmed or assembled wrong from Ford originally. I know how critical the measurements need to be in any differential. Everythings got to be as close to perfect as possible . You might quiet it down for a while, but the misalignment is going to rear it's ugly head, that's a gimme. You might need to go to another dealer that employs a expert in differential measuring and fitment.

Sent from my N9131 using Tapatalk

 

[99WhiteC5Coupe]

Easy job.

Undo the fill plug at the top then the drain plug at the bottom. Reinstall drain plug. Buy the hand pump that fits the larger top amsoil bottles. The Ford friction modifier bottle is small enough to just put up to the fill hole and squeeze.

Factory uses red thread sealer on the plugs. I was unaware of this and buggered up the plug trying to get them off.
Heat them up with a torch and they will come right off and you won’t need to replace the plugs like I did. Though they are cheap if you just want to buy new ones in case.
View attachment 28890
View attachment 28892
You can see where I buggered that one up.
May as well do the front too. Only rub is you need to pump the fluid out of the front diff.
And don’t forget the transfer case but DO NOT use anything but the proper Transfer Case fluid from Ford. None of the generic multicase fluids, none!
Those plugs came out easy as pie since the TC case housing is aluminum.

Thank you.

Curious - what is the green plug in the fluid?

PS - What part of Kentucky? A family member lives near Burnside (Lake Cumberland area) and the road to their home had been blocked by flood waters, since last Monday. They’re at the end of a dead-end county road, and can’t get out other than by boat.

 

[Boostedbus]

Well I got a question for all you guys? This is the first post I can remember about gear whine in a fourth edition. Why are you padding down a problem with slippery oil and friction modifier? Sounds like our op needs to pursue the original problem from Ford. Something was shimmed or assembled wrong from Ford originally. I know how critical the measurements need to be in any differential. Everythings got to be as close to perfect as possible . You might quiet it down for a while, but the misalignment is going to rear it's ugly head, that's a gimme. You might need to go to another dealer that employs a expert in differential measuring and fitment.

Sent from my N9131 using Tapatalk

You are exactly right about the measurements being critical. Sometimes it’s hard to get them set up with all tolerances falling into place especially if the housing is made a little out of spec. That’s why I fought trying to get Ford to replace the whole unit. If some of the tolerances are out of spec on the housing itself it will be impossible to dial in the ring and pinion perfectly. If it gets worse I will pursue taking it back and fighting for total replacement including the housing.

 

[Black]

Well I got a question for all you guys? This is the first post I can remember about gear whine in a fourth edition. Why are you padding down a problem with slippery oil and friction modifier? Sounds like our op needs to pursue the original problem from Ford. Something was shimmed or assembled wrong from Ford originally. I know how critical the measurements need to be in any differential. Everythings got to be as close to perfect as possible . You might quiet it down for a while, but the misalignment is going to rear it's ugly head, that's a gimme. You might need to go to another dealer that employs a expert in differential measuring and fitment.

Sent from my N9131 using Tapatalk

Certainly would be doing the same if under warranty personally but he seems to be good just dealing with it so the Amsoil option as it has quieted down a couple rears I did not want to pay to have rebuilt.

Thank you.

Curious - what is the green plug in the fluid?

PS - What part of Kentucky? A family member lives near Burnside (Lake Cumberland area) and the road to their home had been blocked by flood waters, since last Monday. They’re at the end of a dead-end county road, and can’t get out other than by boat.

That is the plug for my oil catch pan. It has a tab inside the pan so it just unscrews but actually can’t be fully removed so one does not loose it.

I am live about an hour north of Cumberland. I have property about 40 minutes south of Cumberland as well. If we get this rain to stop I need to get down there to check on it.
Cumberland Falls is in the area and normally about a 68’ waterfall it is currently about 2’
We have had so much rain it is pretty bad in a lot of places.

 

[99WhiteC5Coupe]

Certainly would be doing the same if under warranty personally but he seems to be good just dealing with it so the Amsoil option as it has quieted down a couple rears I did not want to pay to have rebuilt.


That is the plug for my oil catch pan. It has a tab inside the pan so it just unscrews but actually can’t be fully removed so one does not loose it.

I am live about an hour north of Cumberland. I have property about 40 minutes south of Cumberland as well. If we get this rain to stop I need to get down there to check on it.
Cumberland Falls is in the area and normally about a 68’ waterfall it is currently about 2’
We have had so much rain it is pretty bad in a lot of places.

When my sons were young - we often vacationed at Lake Cumberland. Also, many visits to the Cumberland Falls Resort, staying in the lodge. My sons loved to go horseback riding there. Now taking my grandkids there - and my granddaughter loved the Big South Fork railway trip.

 

[aagitch]

Did they rebuild it with new parts or did they reuse the ring and pinion??

Swap out your fluid for Amsoil Severe Gear Oil and use Ford friction modifier.
You may loose the shine completely.

My Explorer had very noticeable whine. I swapped fluid granted it was a bit milky that I drained. But with the Amsoil the rear was super smooth and quiet. A couple quarts and friction modifier will Run you about $30 and the rear is easy to swap fluid.
Worth the shot to get rid of the whine and better gear oil.

What weight did you use. I swear the manual said 75w-85 but I can only find Amsoil 75w-90. Or does it matter even?

 

[Black]

75w-90 Severe Gear in black bottle not the silver bottle standard stuff.

Looks like you are just down the road a bit.