Rear Differential Replacement

[Cerberus]

7 hours ago, omar302 said:

Seems RDU failure are becoming more common than before. 

 

to be fair, there is an obvious fluid leak stain at the output shaft, so it probably ran dry.

If the fluid level is kept right, they last quite well.

I know i ran with mine 'dry' or effectively empty for quite a while. 

like tens of thousands of miles, and yes its shot now, but i can't help but wonder if it would in this state if it had fluid in it the whole time.

Bad mechanic (me), no donut. 😒

[honerboys]

cerberus don't beat yourself up too bad - sure you could have checked the fluid level occasionally ( i never checked mine either) - mine did have lots of fluid in there..just lots of metal also - of course Ford could have put a drain on it at almost no cost and then maybe? we would have looked at it sooner

[honerboys]

that pull & pay parts yard contacted me that a 2014 edge had just arrived in their yard - went out there and pulled the differential out - took 2 hours - jspec i took your advice and removed the entire pass side knuckle - hard to do in a yard - they don't allow you to bring in a jack so you're unbolting things under spring pressure - but it is in my garage now

 

it's an exact replacement for mine - most of the oil dumped at the yard but i set it on end in my drain pan and got out 6-7 ounces of oil - i don't see any metal in it so maybe i got lucky

 

my plan is to get new seals and flush it out - i have some 75w-90 gear oil here to flush - or should i use something like kerosene to flush it? - the seals cost almost as much as this unit - pull & pay charges a flat price for parts no matter what kind of car they come from - so a differential for a ford is the same as one from a porsche - it was $128 out the door - hopefully get this in, in the next 30 days (that's the extent of their warranty)

 

i am also planning on drilling a drain into it - anybody have a quick link to instructions for that? - that way i can make changing it's oil an every 10K mile or so job - thanks for all the advice - will check back when it's in - also going to open my bad one up and see what's what in there

[Cerberus]

Nice find.

I wouldn't do a kerosene flush, especially with the condition of the RDU and it's fluid being apparently very good.

 

I also would not drill it to create a drain, nor change the fluid every 10k.. but that's just me.

[honerboys]

reason not to drill drain? - i'm seeing online that these need an occasional oil change - the one i just got is 10 years old with it's original oil (i assume) - just curious

[Cerberus]

41 minutes ago, honerboys said:

reason not to drill drain? - i'm seeing online that these need an occasional oil change - the one i just got is 10 years old with it's original oil (i assume) - just curious

Changing fluid is good. Compromising the structural integrity of a load bearing member is unnecessary to perform the fluid change, it just makes it easier.

 

Also, if in fact the unit has the original fluid and is in as good a condition as you say, that would suggest that regular fluid changes are less necessary than you might think.

Mine ran empty for many miles and did not fail completely.. yet.

[Nancysue]

I have a 2016 Ford Edge. The car has 78,000 miles on it. The rear differential needs to be replace. I was told Ford does not have the parts needed. Has anyone else encountered this problem?

I  have been a Ford Customer for a long time. Are they abandoning their long time customers?

[Biker]

On 9/11/2024 at 9:55 PM, Cerberus said:

Changing fluid is good. Compromising the structural integrity of a load bearing member is unnecessary to perform the fluid change, it just makes it easier.

 

Also, if in fact the unit has the original fluid and is in as good a condition as you say, that would suggest that regular fluid changes are less necessary than you might think.

Mine ran empty for many miles and did not fail completely.. yet.

Very good point. When the OE puts a drain plug in, such as in my 2019, they redesign the case with a thicker bulkhead to support the drain hole. 

I think fluid level is more important than an actual change. If the level stays full, the fluid will be good for a long time. I just changed mine after 147,000 kms, and the fluid was actually in really good shape. 

It's easy enough to maintain the level with just a fill plug. 

 

I'd be more itchy to change it if it sees hard use in hot conditions.

Edited October 9 by Biker
Typo

[FBZebra]

On 10/8/2024 at 5:17 PM, Nancysue said:

I have a 2016 Ford Edge. The car has 78,000 miles on it. The rear differential needs to be replace. I was told Ford does not have the parts needed. Has anyone else encountered this problem?

I  have been a Ford Customer for a long time. Are they abandoning their long time customers?

It sure seems like it. They produce a poorly designed product and then leave us hanging. No way these should be going bad this quick. 

[honerboys]

nancysue - i looked for a S-154D for my 2014 - is yours the same? - i found this (link to ford dealer) - in the details it says it replaces the S-154D - and another one...F2GZ-4000-A - $1800

 

https://www.fairwayfordparts.net/oem-parts/ford-axle-assembly-rear-mu7z4000j?srsltid=AfmBOorOZluLKIRBlwgAy_fxBffkX5KE-l3YPR8NLNjRj30YH9ih5wPl

[honerboys]

if anyone is looking for one of these in the denver area - i just got an email from the pull & pay denver location that they just received a 2014 edge AWD on the lot 

[honerboys]

The RDU saga - long post

    So I tackled the install of my “new” RDU last week – it took about 7-8 hours for the complete job – seemed too long for me – the problem was those T-50 torx bolts that hold the RDU to the front brackets – I got the drivers side loose and out easily, but the passenger side ones would not come loose – to the point that the spines in the bolt stripped out and ruined my bit – wound up just removing the entire bracket and using the air hammer and chisel to get those bolts out of the RDU – that accounts for at least an hour and a half

 

   The rest was pretty ordinary – just a lot of removing and installing bolts – one problem I encountered was the axle nut on the RR roughed up it’s threads while removing it – the edge of the nut was hammered in to lock it (I assume) – I could not see a way to release it from the threads so it flattened out the threads a bit – It went back on and torqued to specs but, if I ever have to remove it again I might need a new axle shaft - my Launch code tool coded the replacement RDU to the PCM

 

  So got it all back together and took it for a test drive – while the growling/grinding noise is gone, it clicked when turning from a stop – I disconnected the electrical connection on RDU and noise disappeared – so I’m figuring the clutch portion of the replacement RDU is defective..?? – I removed the clutch part of the replacement and it had gear oil in it – there is a seal between the two but it failed – I don’t know what the oil does to the clutch part but I’m pretty sure that’s what caused the clutch to fail

 

   To remove that seal with diff in car you have to basically destroy it – the seal on my original diff did not leak, but it to was looking rough from the removal process - I thought it a good idea to replace it and looked up the part number stamped on it – went to Ford and the one they had (same part number) was way to big – when they looked up the part number it showed the seal for the front of the clutch where it connects to drive shaft, not the seal between the diff and the clutch – they could not explain why they both have the same part number and that was that – I wound up rehabbing my original seal and reinstalling it

 

     I took the clutch portion off my original RDU and put it on the replacement RDU – removing that from the gear portion is pretty simple – the code for the clutch portion is etched into the unit (pic) – recoded my original clutch back into PCM

 

     I disassembled the gear portion of my original bad RDU – the gear set looked to be ok as did the left and right side output bearings – the growling was from the pinion bearings – these are double row ball bearings – the cage they are in is plastic – I’ve never seen that before – I don’t know what caused the bearing to fail (it was always lubricated) – it gouged up the race and balls pretty bad, so that’s where all the metal in my oil was from – I removed the race from the pinion gear with a puller – if you could find these bearings I think these units would be rebuildable – the L/R side bearings are a standard bearing (LM-501314) – the pinion ball bearings had no identity markings on them so I’m not sure if they can be obtained

 

    So the car is back on the road and the AWD seems to be operating normally – if that rehabbed seal does not leak I think it’s a good fix - total cost for this was around $500 – that includes new wheel bearings, axle shafts, the junkyard RDU, seals, and fluid – hopefully it lasts the rest of the car’s life – thanks to all for the input and advice – and I took the above advice and did not drill a drain into the RDU – I’ll change as much of the oil as I can every 20K miles or so and hope it holds

[Biker]

Great work! Nice write-up and pics. 

[ford2timer]

I have a 2015 SEL AWD 3.5L. Was going to be my last car. Owners Manual says RDU fluid doesn't need to be changed until 100K miles. So it wasn't serviced. 

Now have 80k miles and bearing area of the pinion shaft forward housing  emits major grating, grinding noise when using a stethascope device to listen to it. In the cabin it is just a noticeable hum which is load / throttle  sensitive.

I took it to a dealer when I was out of town and had the fluid changed. $200+ and only a slight change, possibly wishfull thinking.

Listening to the web I also seem to be facing a $2K waterpump change around 110- 130K miles and possibly a PTU any time now.

It all has me seriously re thinking this Ford thing. My 1st EDGE was a 2008, with same drive train, bought used at 30K miles and driven to 108K miles trouble free.

This "new and improved" version is apparently a mistake.  

PS: I use it in the desert south west and pacific coast (when AZ gets too hot), it has not been submerged or off roaded, and doesn't tow anything, only occasionally carries more than 2 people, seldom exceeds 80MPH and has been serviced by Ford dealers on the regular factory suggested schedule.

What gives and what is recommended?  Rear Difs used to go 200K mi. 

[honerboys]

hey 2timer - welcome to the forum and the world of ford bad RDU's - if your noise is from area A in the pic below your screwed and i believe your RDU is on it's way out - those are the actual pinion ball bearings - very hard to remove and i couldn't find a marking on them and so cannot find any availability for them -  if your noise is from area B, that is a readily available bearing - it is also fairly easy to remove - i think your 15 is about the same as my 14 also with about 80K on it - and yes a rear differential should last longer than the rest of the car - the inside of these is a pretty basic differential - so it seems ford has dropped the ball on these - first for not recommending fluid changes and, second for not putting a drain in them, and third for not making them better - but i guess if you believed the first you would not do the second

Edited November 15 by honerboys