PTU discontinued by Ford

[bigblock]

From the owners manual, the PTU should take 12 ounces (0.35 L) of "SAE 75W-140 Synthetic Rear Axle Lubricant"

 

Yep, I didnt put ATF in the PTU. The transmission leaks out some fluid when you pull the PTU.

[junehhan]

Out of curiosity, are these newer Edge and Edge Sports still as susceptible to PTU failures? Are they any easier to change the fluid? I remember looking at PTU fluid in an older Escape are marveling at how horrible the fluid looked at just 40k miles.

[WWWPerfA_ZN0W]

No issues thus far, thank goodness! I believe one member did change the PTU fluid very early on, and it looked fine.

[junehhan]

So us new Edge owners are good? When I bought my Sport last week, I had completely forgotten just how bad the older PTU setups have been. Does the PTU still need to be removed to change the fluid?

[WWWPerfA_ZN0W]

Factory manual would have you remove the PTU (in 2007-14), but it is not necessary to do so, even with the lack of a proper drain plug. Not sure on the 15+, but it looks like there is a drain plug from the fordparts.com pics:

http://www.fordparts.com/Commerce/RenderIllustration.ashx?id=390180942&f=3&n=F2GZ7A246C

Callout Name: 7A010A

Part Number Part Description Price Your Price Availability Quantity

7A010A

Auto Trans Oil Drain Plug

4WD 2.7L Dual Over Head Cam 4V DI GT V6 GAS/FFV Less Hot Weather Group Hot Weather Improvement Pack 1

 

 

[junehhan]

I will have to check it out when I take it in for service next Thursday morning. AWD systems have always scared me so I would like to replace the factory fill with a really high performance lube such as Redline or Amsoil.

[WWWPerfA_ZN0W]

Yeah, one of the biggest arguments against 4 wheel drive type vehicles is the maintenance costs. At least you can overcome a basic "flaw" in Ford's PTU design pretty easily.

[junehhan]

Well traditional 4WD or a traditional AWD setup utilizing a Torsen center diff or viscous coupling is pretty reliable and durable. It is these Haldex like systems that make me very nervous, but these are pretty standard with FWD based platforms.

[JohnCT]

I just finished installing a new PTU on my 2010 edge and thought id share some info/best practices.

 

Good work. Screwing up the courage to get this done some Sunday before it totally grenades.. The one I have is also a G and was disappointed to find it has no drain. I've read that the B version (export) has a drain! ?

 

I have a buddy in the exhaust biz and was thinking of having him spin all the exhaust bolts and leaving them loose for me. I no longer have torches and the exhaust scares me more than any part of this job.

 

Did you replace any seals? I've seen a couple of procedures on line but am not sure what, if any, seals are required to be replaced if a new PTU is installed.

 

John

Edited August 21, 2016 by JohnCT

[bigblock]

In terms of exhaust bolts, I just used a cheap screw on propane/Mapp torch from the hardware store. Get the nut good and hot, hammer on the socket and crank on it with a breaker bar. Theres only 4 on the main pipes, and youll need to take off the pass side cat which is 4 more. Nice thing about the cat is if the nut is frozen the stud will unscrew out. I had that happen on eone of the studs.

 

My ptu came complete with the seals intact. Went back in much quicker than it came out. Overall the job isnt that bad, just be patient and prepared contort your arms and handa a bit.

Edited August 21, 2016 by bigblock

[Brian K]

I was looking through the owners manual and noticed that it said the PTU took 12 oz. (0.35 liters). Then I looked in the Ford Factory Service manual and it said 18 oz. (0.53 liters). I wondered if the liter conversion and numbers of .35 L and .53 L could have been a typo and the 12 and 18 oz. could have been a conversion from liters - so I took both manuals to the Ford service department at the local dealership and asked the service manager which was correct. He asked a mechanic who said the Factory service manual would be more accurate and that more oil is better. I told them I had installed a drain so I could change the PTU oil and they said that was a great idea and kind of rolled their eyes when they talked about Ford's lack of a drain and no recommendation on servicing it and that they change lots of PTU's.

[JohnCT]

I was looking through the owners manual and noticed that it said the PTU took 12 oz. (0.35 liters). Then I looked in the Ford Factory Service manual and it said 18 oz. (0.53 liters)

 

It's my understanding that both are correct; that is the 12 OZ was the original fill specification for 2007 (first year). Once the PTUs started croaking in the first months of production way back in 2007, Ford changed it to filling to the bottom of the fill plug, which would be 18 OZs more or less, theory being more oil would help cooling.

 

[speculation] Ford made the decision to not make simple upgrades (drain plug - cat heat shield) to prevent the PTUs from failing after 30K miles or so, but to let subsequent buyers foot the bill. They seem to think this is a better plan than fixing their mistake. [/speculation]

 

For those of you who intend to keep your Edge/Explorer/Flex/Mazda I'd put in the best aftermarket oil I can find and fill it to the bottom of the fill plug. For routine service, pump out as much as you can and add back all it will take. Do this at every oil change.

 

[editorial] If Ford decided the best thing for them would to be to keep the design error in production until the next generation, the very LEAST they could have done is to inform us to allow us to mitigate the damages a bit. Perhaps a note in the owner's manual starting in 2008 such as this:

 

Greetings from Ford. It has come to our attention that we made a design boo-boo with regards to the Power Transfer Unit (PTU) in your new Ford Edge AWD vehicle. Whereas we designed the PTU to last the life of the vehicle, it turns out that in real life, it's a bit shorter than that (expect 30K to 60K miles). So instead of us addressing the problem in 2008 and up Ford Edge vehicles, we have decided to leave well enough (for us) alone and let you deal with it.

 

So our recommendation is to drain and refill the "filled for life" fluid out of the PTU at every oil change. While we concede this extra maintenance is annoying, we feel that you should be grateful we are giving you a plan to perhaps prevent a $2500 bill. Don't forget to avail yourselves to our wonderful Ford themed merchandise such as watches and hoodies at Ford.com

 

Thanks for your understanding.

 

The Ford Team [/editorial]

 

 

If I had at least known that the PTU would die in my wife's car at 65K miles, I would have serviced it religiously since the car was new and avoided this huge expense. It's bad enough Ford never implemented a redesign, but to not even tell us that doing maintenance on the PTU would likely prevent an expensive repair is obscene. It's too late for me but any of you who have a PTU that's working properly MUST get it serviced.

Edited August 24, 2016 by JohnCT

[Waldo]

But there's no evidence that doing maintenance prevents the failures. There's a guy over on the Flex forum who changed his PTU oil every 20K miles from new and still had a failure at about 65K.

 

My theory is it is the variation in manufacturing that causes the PTUs to fail. Sure having more fluid would likely increase the robustness to that variation, but I believe that a PTU is destined to survive or fail based on it's internal variations and there's really nothing you can do about it.

[akirby]

That would explain why there is no fluid change recommendation.

[omar302]

Ford knows that heat kills the PTU, hence they extended the warranty on them for those in very hot countries & even provided the replacements with drain valves with ~9K or ~18K mile drain/refill intervals.

 

http://www.fordedgeforum.com/topic/13533-13m01-middle-east-ptu-extended-warranty/

 

REASON FOR PROVIDING ADDITIONAL COVERAGE

Extended high speed vehicle operation in high ambient temperatures, in conjunction with off-road driving in sand, may result in sludging of the fluid within the PTU and/or seal leaks. PTU sludging typically produces symptoms such as a whining noise while driving or clunk/harsh engagements when shifting to drive or reverse. Continued driving in these environmental conditions may damage the PTU and result in a loss of AWD functionality. Affected vehicles can still be driven in FWD mode if the PTU function is compromised.

SERVICE ACTION

If dealer diagnosis indicates that the PTU requires replacement, dealers are authorized to replace it with a new Middle East Service PTU that contains a drain plug, which enables convenient fluid replacement at regular intervals. Dealers are also to apply a sticker to the inside cover of the vehicle Owner Guide that details revised fluid replacement maintenance intervals of 30,000 kilometers for normal use, and 15,000 kilometers for severe duty/sand driving use. At the conclusion of the repair, dealers are to provide vehicle owners with an Owner Information Card, which details the revised fluid replacement maintenance intervals.

[JohnCT]

But there's no evidence that doing maintenance prevents the failures. There's a guy over on the Flex forum who changed his PTU oil every 20K miles from new and still had a failure at about 65K.

 

My theory is it is the variation in manufacturing that causes the PTUs to fail. Sure having more fluid would likely increase the robustness to that variation, but I believe that a PTU is destined to survive or fail based on it's internal variations and there's really nothing you can do about it.

 

The oil in my PTU was found to be: 1) low 2) burned into a black paste.

 

I'm an EE, not a ME, but I know that heat destroys things mechanical just as it does things electrical. I know enough that the only way synthetic oil will sludge is because of heat, and lots of it. I also know that sludged oil cannot protect bearings anywhere near as well as non sludged oil can. I can't speak to the fellow in your example who lost his PTU at 65K miles despite rigorous maintenance, only to say that sometimes things do fail for isolated reasons. I've also read of others who had the beginnings of PTU failure (noise mostly) and serviced the PTU several times and forestalled failure of the PTU apparently. Also, most seals will fail because of excessive heat which will lead to leakage of the precious little fluid it contains, leading to more heat. I don't know what's different in the "G" version of the PTU, but maybe it features redesigned seals that are teflon or some other synthetic material that can take heat better. Keeping the oil inside is half the battle.

 

I'm sure that Ford has done several engineering analysis of the failed PTUs and whatever they've found was implemented in the redesigned Edge/Ex/ Flex. Since they've added a drain to the redesigned PTUs, it seems that keeping fresh fluid in the PTU is a priority. Since another objective would be to keep the fluid from coking into sludge, I would be surprised if the cat wasn't relocated in the redesign or a heat shield installed between the cat and the PTU. Considering the flash point of the synthetic fluid is well over 350 degrees, imagine how hot the PTU gets in service!

 

I think the PTU as is is fairly well designed except for it's oil capacity, but also think that if it wasn't located so close to the cat, it would survive just fine even with but half a quart of fluid.

 

If I planned to keep our Edge I would explore ways to keep the new PTU alive, but it's going in the spring. Looking at a Caddy XT5 and one of my golfing buddies just picked up a new Audi Q5 which is a real nice car. I would have picked up the Lincoln MKX (particularly since I'm an X plan buyer) but Ford has screwed me too many times over the years.

 

John

[bigblock]

Just as a data point, the gear lube in my ptu still looked decient and was not low when it failed @ 150,000 miles. This is my first transfer case/ptu, but i've certainly seen worse fluid in functioning difs. Looks like there are a couple of different failure modes, but regardless any auto company should be able to put together a solid gearbox after a century of experience.

[Brian K]

No evidence that maintenance prevents failures????? One failure story does not make a pattern and certainly should not persuade people not to do regular oil changes on their PTU if they have the know how. There always will be few that fail prematurely regardless of maintenance intervals. After installing a drain plug and draining and filling mine about 10 times, my vehicle does feel smoother and the oil is getting cleaner - but is still pretty dirty. I also added more tin to the heat shield that is there to hopefully prevent as much heat soaking of the PTU from the Cat. I just used a piece of tin siding and screwed it to the little OEM shield. It is a bit of a battle to get out, but once I learned what to do, it is much easier now.

You have to admit - new clean oil in the PTU can only help prolong it's life and not adding/topping up/changing will most certainly reduce it. That is just common sense.

[Waldo]

 

You have to admit - new clean oil in the PTU can only help prolong it's life and not adding/topping up/changing will most certainly reduce it. That is just common sense.

 

Well yes and no. The thing about the PTU oil is that it's very sensitive to the heat threshold. Keep it under that threshold and it will be fine forever, but get it over just once and it's toast. So say you drive 20,000 miles and never overheat the oil and then change it. You've wasted the oil change as the new oil is just as good as the stuff coming out. But then say at 21,000 miles you tow in the desert mountains and overheat it. Then you go until 40,000 miles before changing it. Now you've driven 19,000 on bad oil and likely caused PTU damage.

 

The point is since it's impossible to know when that oil has gone from good to bad, it's impossible to come up with a maintenance schedule that provides any sort of guarantee. The real problem is the source of the overheating, and my theory is that comes from the internal production variation in the gears and such that create more friction than was intended in the design. As I said, that's not something you can fix and if it's generating enough heat to cook the oil, only changing the oil every 500 miles is going to prevent the inevitable failure.

[JohnCT]

 

Well yes and no. The thing about the PTU oil is that it's very sensitive to the heat threshold. Keep it under that threshold and it will be fine forever, but get it over just once and it's toast. So say you drive 20,000 miles and never overheat the oil and then change it. You've wasted the oil change as the new oil is just as good as the stuff coming out. But then say at 21,000 miles you tow in the desert mountains and overheat it. Then you go until 40,000 miles before changing it. Now you've driven 19,000 on bad oil and likely caused PTU damage.

 

The point is since it's impossible to know when that oil has gone from good to bad, it's impossible to come up with a maintenance schedule that provides any sort of guarantee. The real problem is the source of the overheating, and my theory is that comes from the internal production variation in the gears and such that create more friction than was intended in the design. As I said, that's not something you can fix and if it's generating enough heat to cook the oil, only changing the oil every 500 miles is going to prevent the inevitable failure.

 

You make some good points, but we don't know exactly what happens in the PTU without being privy to Ford's post-mortem. As for my wife's car, we NEVER took it into the mountains or went off roading or pulled a trailer or even did a long stretch over 80. Most of it's miles are around town and some highway trips at 65 mph. It died at 65K but had been making noise for the last 15K at least (I thought it was a rear wheel bearing singing).

 

But, since the oil is clearly coking, some sort of catastrophic overheating is happening. I can't believe it's just friction losses that cause heat high enough to coke synthetic fluid whose flash point is at least 350F. If the flash point is indeed 350 (say), does this mean that if the oil stays below 325 it will be fine forever? I have a feeling that the heat damage to the oil is cumulative, not from a specific binary incident failure, although I'm certainly willing to listen to someone with more understanding of oil behavior with regard to heat as my comments are admittedly pure speculation.

 

Still, I think the primary reason the oil is dying is the PTU getting to about 300F and slowly cooking the oil due to it's proximity to the catalytic converter, which is why routine maintenance will help IMO. However, I also believe you're correct in that a single incident (as your examples mention) where the PTU gets over the flash point temp of the oil can undo a recent maintenance.

 

If I were going to keep the Edge, I would mitigate the heat gain from the cat as much as possible as I believe this is a more likely source of the heat than friction losses are. A heat shield would seem not only prudent but necessary. I'm installing the new PTU as is but if I planned to keep the car I would drill and tap it for a drain plug. I'll let the next poor sucker deal with it; at least it will have a new PTU when I off it.

 

John

Edited August 31, 2016 by JohnCT

[Waldo]

 

But, since the oil is clearly coking, some sort of catastrophic overheating is happening. I can't believe it's just friction losses that cause heat high enough to coke synthetic fluid whose flash point is at least 350F. If the flash point is indeed 350 (say), does this mean that if the oil stays below 325 it will be fine forever? I have a feeling that the heat damage to the oil is cumulative, not from a specific binary incident failure, although I'm certainly willing to listen to someone with more understanding of oil behavior with regard to heat as my comments are admittedly pure speculation.

 

Still, I think the primary reason the oil is dying is the PTU getting to about 300F and slowly cooking the oil due to it's proximity to the catalytic converter, which is why routine maintenance will help IMO. However, I also believe you're correct in that a single incident (as your examples mention) where the PTU gets over the flash point temp of the oil can undo a recent maintenance.

 

 

I have it on very good authority that it is a binary condition in the oil and that yes, if you do keep it below the temp (can't remember what that temp is, think it was around 340) that it will last forever. I can also tell you that Ford does extensive testing on heat management and that if the CAT was able to get the PTU oil over 340 on it's own, they absolutely would have designed a more robust shield or put in some ducting (like they did on the Flex and Explorer). If their testing had shown that the PTU would get over 340 during customer usage, they would have done something different (like they did with the Police vehicles). I also know that back when the Edge and Explorer first came out, the AWD volume was substantially higher than Ford had predicted which led to the supplier running short on production, which tends to cause them to send out parts that aren't quite as "robust" as they should be.

 

So anyway, all that leads me to believe it's not an inherent flaw that maintenance is going to prevent, it's more a lottery as to the manufacturing variation from one vehicle to the next.

[WWWPerfA_ZN0W]

Would like to add that PTU failures happen even on the units that are temp monitored and cooled. Ford keeps revising the internal design (though not advertised) of the PTU to increase its' lifespan, at least in these "higher end" versions.

[JohnCT]

Would like to add that PTU failures happen even on the units that are temp monitored and cooled. Ford keeps revising the internal design (though not advertised) of the PTU to increase its' lifespan, at least in these "higher end" versions.

 

Not that it matters, but I would have preferred the short life of the PTU was due to an overlooked factor (airflow, prox to cat, etc.) than some fundamental design flaw. Ford has been building these types of PTUs in earlier vehicles and didn't have a problem with them. To say that it's not an external factor in the Edge version means that Ford not only designed a bad mechanical device, but did NOT life test them.

 

Again, it doesn't matter, but I would have felt better about this if Ford built a hundred of these in a pilot run and ran the snot out of them on a load fixture and found them adequate. But if external heat from the Edge exhaust is not causing the oil coking, then either Ford didn't run the pilot production on a test fixture or did and decided to roll the dice.

 

If you look at Ford's history, the later makes sense. Ford decided to put alum heads on the previously bullet proof Essex V6 and found out that they were spitting out their head gaskets in less than 60K miles. Instead of fixing either the head design or even upgrading the gasket set, they continued to build the engine as is until the end of production. Aftermarket gaskets from FelPro fixed the problem. The CD4E automatic went into production in 1992 with a valve body design problem that would cause a line pressure runaway that would destroy the forward drum. They never fixed the design letting the customers to shoulder the cost of a new trans. The aftermarket fixed this problem as well. I had to rebuild two CD4Es for this problem, and put in a Transgo CD4E Jr kit to address the valve body problem. Another company (Sonnex?)makes a better fix that's more expensive and requires special tools.

 

I have two AWD Escapes for my business that use a Haldex type PTU similar to the Edge. I'll run the heck out of mine and take a temperature of it and report back. I'd be stunned if it gets much past 200F. BTW, the PTUs in Escapes are not known to be problematic.

 

John

[WWWPerfA_ZN0W]

PTUs in the Escape may not be problematic, but the engines (and the 6F35 transmissions) ... LOL. Somewhere there's a balance ... Def interested in the temps you observe for the PTU. How do you intend to go about that?

[akirby]

Ford would save a bunch of money on warranty repairs if the solution was as simple as more heat shields. And if the problem really is manufacturing tolerances (which makes sense to me) then that's not something that will necessarily ever show up in testing. It's still Ford's fault either way but I don't necessarily think it's a lack of testing.