Jump to content
JohnCT

PTU discontinued by Ford

Recommended Posts

Did you put a drain plug in it?

 

I was thinking about it, but it took longer than I expected to get the old one out that I just kept going and installed the new one without drilling it. I was so over being underneath that car! Besides, I suspect the PTUs only fail under severe duty - like driving up hills or doing 65 for several hours. My sister will use it for grocery shopping and visiting mom. She won't put 15K miles on that car in the 10 years she probably has left driving and I doubt it will ever be driven past 45 MPH again or even driven in the snow.

 

John

Share this post


Link to post
Share on other sites

Despite the opinion of others here, I'm convinced the big problem with the PTU is a long term coking of the fluid due to friction loss and heat gain from it's installed environment. Either source of heat by itself is manageable, but together they're a problem.

Excellent argument, but how do you explain that the majority of cars over 100k and don't have a PTU problem? MacFordEdge went 200k if I remember correctly and I have over 100k on my MKX.

 

I asked my service manager about the PTU a couple of years ago. He said they replace two or three a year, not all that big a deal. I asked him what did he think was causing the failure and he said (don't know if it was the local dealer or Ford he was referring to, but it was clear he was well advised on this), that they had traced the problem to a leak in the seal. If the fluid leaked out of the seal the remaining lubrication would cook and stop lubricating.

 

They also found my seal leaking around 90k (told me it's one of the things they look for at each oil change) and I had it changed under warranty.

 

No drips under the car, they said there telltale signs and that it was only leaking while driving. Drips on the ground come at later stages. (Presumably after the fluid was cooking). Anyway, I'll have the fluid changed around every 36k per the owner manual. (Severe service).

 

I have to believe that if it was just the location next to the cat, this would be common to all AWD & I would think we would be seeing a much larger percentage of failures. I have to believe Ford engineer's did their due diligence and knew full well the area thet were installing it into. Heat shield?

Share this post


Link to post
Share on other sites

Ahhh, so "that's" how he went 200k and never had a problem. lol

  • Like 2

Share this post


Link to post
Share on other sites

Ahhh, so "that's" how he went 200k and never had a problem. lol

I did my research. I aim for longevity at low cost.

  • Like 1

Share this post


Link to post
Share on other sites

The last theory I heard was that individual parts tolerances were adding up causing too much friction and heat. That would certainly explain why it's hit or miss. Maybe that's causing the initial seal failure.

  • Like 1

Share this post


Link to post
Share on other sites

I did my research. I aim for longevity at low cost.

Same here- I bought FWD specifically due to the PTU issue on AWDs.

Share this post


Link to post
Share on other sites

Just another data point. My 08 AWD Limited has 210K on it. I had to replace a PTU seal at 90K (which I caught right away) but never had any other issues. Perhaps it is luck of the draw and perhaps I'm one of the "lucky" ones but mine is still going strong.

Share this post


Link to post
Share on other sites

Excellent argument, but how do you explain that the majority of cars over 100k and don't have a PTU problem?

 

 

 

We know how many Ford made, but do we really know how many fail? When the Jeep dealer asked about our trade, I told him it was an Edge and had a problem. *He* asked if it was the PTU. Seems they had a bunch of Explorers and Flex' they took on trade that they had to replace them in. I laughed, told him yes, and I had the new PTU in a box in the back and he still didn't want it despite it being a loaded Limited pearl white with vista roof and nav. The word is out.

 

When I brought one of my Escapes in for a trans rebuild a couple of years ago, I asked the owner (independent shop) how the Edge trans were, and he told me the PTUs were far more trouble. It was then that I suspected the noise and vibration I was hearing was not the rear wheel bearing.

 

I have to believe that if it was just the location next to the cat, this would be common to all AWD & I would think we would be seeing a much larger percentage of failures. I have to believe Ford engineer's did their due diligence and knew full well the area thet were installing it into. Heat shield?

 

 

 

Maybe. I don't pretend to know for sure, but there's definitely a chicken or the egg thing going on. Somebody here who is reported to be "in the know" said the problem could be a one time overheat of the PTU fluid, so regular maintenance would not prevent this (I had suggested a long term coking of the fluid).

 

It could very well be a seal failure leading to loss of fluid leading to overheating of the remaining fluid due to less of it and more friction with less lubrication. The other possibility is that the box just gets too damned hot causing the seal to fail from the scorching heat, or failing due to loss of lubrication by the scorched fluid. Again, chicken or the egg.

 

The other thing that bothers me is that the PTU is mostly free wheeling; the majority of engine torque is transferred to the front wheels through the intermediate shaft, not the PTU. Also, there are no clutches in the PTU. Is it really possible that this box generates that much heat without handling that much torque just from friction losses? Perhaps. Again, I'm not a mechanical engineer.

 

Back when I planned to keep the Edge, I was going to mount a thermocouple on the far side off the PTU (away from the cat) and measure the temperature of the PTU during stop and go, highway driving, and pulling long hills (which we live among around here).

 

If the PTU showed steady temperatures well within the capability of the lube, it would make sense that a leak might be the trigger. But if the PTU showed wildly differing temps, then my plan was to fabricate a heat shield and air deflector to keep the cat's heat off the PTU and redirect airflow under the car over the PTU.

 

I took a far easier path and gave the car to my sister. Other than the Nav acting up right now, she absolutely loves this car.

 

John

Share this post


Link to post
Share on other sites

Shame you didn't get around to monitoring the temp in the PTU. That would have been interesting to see what's really going on. I have the factory tow option and she's pulled a boat and been towed to FL more than once. It would seem that if anything, towing would put a (heat) load on it more than anything else. I wonder.... if the units failing had aftermarket hitches and exceeded to towing limit recommendations? There has to be some variable that affects some PTU but not otheres. Cant believe it's the heat from the cat as Ford would have certainly considered this (and under all circumstances).

 

If we assume that a single overtemp cab cause the cooking of the lubricant, I would expect to see additional damage as well. Assuming a standard cat is running between 1200° to 1600° and then either through a vacuum leak causing a lean condition or a plug misfiring causing a rich condition, the cat could running as high a 2000°F. At those temperatures, even for a few minutes, I would expect the cat to begin to fail, the aluminum oxide honeycomb could melt causing a partial or complete blockage, or the platinum / palladium coating on the honeycomb may start to melt and reduce its effect its ability to process thw exhaust gas. Either way, a malfunctioning catalytic converter should start throwing codes. Ford should have taken this possibilities into consideration during the design phase.

 

Anyway, I figure that if it goes out I'll just replace it. It already has over 100k on it, so if I have to throw in $1800 for a new one, still worth it if the rest of the car is still cherry. (And it is). $1800 every 100k is not that big a deal considering what car payments would run for a new one.

 

Glad your sister has a great car to drive. That was really nice of you to fix it and give it to her. Consider this a pat on the back. :rating:

  • Like 3

Share this post


Link to post
Share on other sites

One thing not really mentioned is the combination of heat, friction and lastly the small amount of lubrication fluid. 12oz. I believe the Ford engineers are asking a lot from a small amount of lubrication fluid. i.e. 32oz of fluid would withstand heat much better than 12 oz.

 

My local police garage has figured out the PTU issue and stopped failures of the PTU in the Police cars. They change the fluid every 10K miles and the PTU failures came to a screeching halt. Mechanic I talked to said Ford even sent a rep to the garage to find out what they were doing to stop the failures. Simple consistent and frequent fluid changes. They even refill the PTU through the drain plug by using a syringe.

  • Like 1

Share this post


Link to post
Share on other sites

My local police garage has figured out the PTU issue and stopped failures of the PTU in the Police cars. They change the fluid every 10K miles and the PTU failures came to a screeching halt. Mechanic I talked to said Ford even sent a rep to the garage to find out what they were doing to stop the failures. Simple consistent and frequent fluid changes. They even refill the PTU through the drain plug by using a syringe.

 

 

Although the PTU has a fairly severe angle on the ring and pinion, it's otherwise just a gear box with no clutches. It's hard to believe that it's just friction alone (particularly since it's all roller bearing) that could cause synthetic fluid breakdown of this magnitude, which is why I believe the PTU's proximity to the cat is a huge contributing factor. It's tiny fluid capacity is another contributing factor, but still points back to unmitigated heat gain.

 

I have no evidence, but logical speculation would suggest that Ford designed and prototyped several examples of the PTU which were run with full torque to see how the box could cope with stress and heat. I would assume the box would have to have passed these bench tests before production was ordered. My speculation is that the environment the PTU experiences as installed in these platforms was an unforeseen problem that caught Ford by surprise.

 

I unloaded my Edge after installing a new PTU, but if I was going to keep it, the plan was to fabricate and install a heat shield and airflow diverter and monitor the temperatures before and after with a thermocouple to test the effectiveness of it.

 

John

  • Like 1

Share this post


Link to post
Share on other sites

Probably a smart move to dump it. Its only been a few months since i replaced my PTU (which has been running fine) but the other day when my wife was driving the water pump failed suddenly and pumped all the coolant into the oil pan. Needless to say this one is not going to be a cheap fix. Im going to do the min to get it fired back up and trade it in.

I would reccomend that anyone who plans to run up the miles on their edge either replace their pump($$$$) or check their fluids weekly, although i had just checked everything 2 weeks before the incident so its likely that it just let loose within a day or 2. Ford myst have had the intern design the pump location. Id love to see the FMEA for that component.

Its too bad, we were planning on getting a new edge in a couple years since its a great vehicle in terms of power,cargo, and looks, but this was one failure too many. It was also the first car that ive owned which hasnt made it over 200,000 miles.

Share this post


Link to post
Share on other sites

If it was as simple as too much heat from the exhaust that would seem to be a relatively easy fix. I've been told by engineers that they think it's a buildup of manufacturing tolerances resulting in too much internal heat and that's why it only affects some units and not others.

  • Like 1

Share this post


Link to post
Share on other sites

Its only been a few months since i replaced my PTU (which has been running fine) but the other day when my wife was driving the water pump failed suddenly and pumped all the coolant into the oil pan. Needless to say this one is not going to be a cheap fix.

 

Do you mean *literally* into the oil pan? Coolant in the oil will strip the babbitt off the bearings and destroy the engine in a very short time.

 

John

  • Like 1

Share this post


Link to post
Share on other sites

Yes, the oil pump is buried under the timing chains and there are a few threads on the pump seals letting loose and rapidly dumping into the oil pan. I pulled the dipstick and the oil level was way overfilled and milky. Just an asinine design. It sounds like there was a slight change to the water pump design sometime after 2010 model year but I'll never buy another vehicle with that engine in it.

 

THe Edge was still running when my wife shut it off and had it towed. Best case senario is that I'm hoping I can replace the pump, flush the oil system and drive it about 20 miles to the dealer for trade in. Worst case scenario is used/reman engine or just write it off altogether depending on price(only worth around 4500 trade in). I just don't have the time to pull the engine myself.

 

I don't want to hijack the thread, but since most people that are replacing PTU's are also running higher mileage I just wanted to give a heads up on a failure that is probably a bit less prevelent than PTU failure but can easily cost $3-4k for a shop to fix if you blow the engine. Mine died at ~165K miles.

 

Since I sold my cobra last fall, this will be the first time in 22 years there won't be at least 1 ford in my driveway.

Share this post


Link to post
Share on other sites

I don't want to hijack the thread, but since most people that are replacing PTU's are also running higher mileage I just wanted to give a heads up on a failure that is probably a bit less prevelent than PTU failure but can easily cost $3-4k for a shop to fix if you blow the engine. Mine died at ~165K miles.

 

 

 

Hijack away. This is important information to anyone who still has an Edge. Hopefully, something as innocuous as a silly water pump didn't destroy your engine. Hmmm... burying a water pump inside the timing cover... what could go wrong?

 

 

Since I sold my cobra last fall, this will be the first time in 22 years there won't be at least 1 ford in my driveway.

 

 

I left Ford in the early 2000s because of constant auto trans problems and the Essex V6 engine failures (I've had them all). We bought the Edge because my wife liked it, we got a good deal on it, and I had heard that GM had a lot to do with the Edge's transmission design, so I took a chance. The PTU going out at 50K has taught me that sometimes you just can't go home. The Edge is gone and I'm back with Jeep.

 

The last Ford I'll own is one I bought the year I got married: a 1966 Mustang 2+2 bought in 1985. I'll keep this car and give it to my son when I'm all done driving, but Ford has bitten me for the last time.

 

John

Share this post


Link to post
Share on other sites

Yep all cars have their issues , but it would be foolish to buy the same car after having over $5000 worth of issues. I just ordered the new jeep compass with a stick shift and all wheel drive. Since this model had a complete redesign I was hesitant to be the beta tester but my local dealership offers an unlimited powertrain warranty as long as they do the oil changes and basic maintenance. So while its a bit smaller and underpowered Ill give it a go. Its significantly cheaper and is the wifes car anyway ? not to mention i get the family plan pricing.

 

Over the years Ive learned that you cant really trust a manufacturer, its all dependant on the specific model. For me the mustang has been a winner, and wouldnt hesitate to buy another. Just really frustrated over the edge where 2 design errors screwed up an otherwise excellent vehicle that we really loved for our family.

  • Like 1

Share this post


Link to post
Share on other sites

Probably a smart move to dump it. Its only been a few months since i replaced my PTU (which has been running fine) but the other day when my wife was driving the water pump failed suddenly and pumped all the coolant into the oil pan. Needless to say this one is not going to be a cheap fix. Im going to do the min to get it fired back up and trade it in.

I would reccomend that anyone who plans to run up the miles on their edge either replace their pump($$$$) or check their fluids weekly, although i had just checked everything 2 weeks before the incident so its likely that it just let loose within a day or 2. Ford myst have had the intern design the pump location. Id love to see the FMEA for that component.

Its too bad, we were planning on getting a new edge in a couple years since its a great vehicle in terms of power,cargo, and looks, but this was one failure too many. It was also the first car that ive owned which hasnt made it over 200,000 miles.

It is part luck but also maintenance and how you drive the Edge with the 3.5 NA Duratec. I have nearly 600,000 accumulated miles on three Edges with the original water pumps. I do change the coolant often and use full synthetic oil. No proof other than longevity to prove my personal experiences.

  • Like 1

Share this post


Link to post
Share on other sites

Because Jeeps never have problems........

 

 

All cars have problems, even Jeeps. But I've owned an 88 Sable, 95 Sable, two 95 Windstars, 2004 Escape and a 2005 Escape (bought used to replace the Windstars in my business). Both Sables needed transmissions. Fortunately, I specifically ordered the 3.0 Vulcan V6s because they were available so no engine problems. Both Windstars blew transmissions and both needed their Essex V6 engines rebuilt because of head gaskets. Both Escapes needed the CD4E transmissions rebuilt. The only Ford that was bullet proof was my 2000 Explorer Sport that I specifically ordered with a manual because the automatics were known to be junk. Between the German Cologne 4.0 and the Japanese (Mitsu) manual transmission, the power train gave me no trouble. BTW, all the above failures were known issues from the day they were put in production and never addressed.

 

The 2002 Jeep Grand Cherokee we bought new now has about 300K miles on it, and it's on it's original engine, original automatic trans, and original transfer case. In all this time I've replaced the cooling fan, fan controller, passenger side power window regulator, the coil pack and last week the alternator. All these things I did in my driveway except for a vacuum line leak that a garage smoked out (rubber lines at charcoal canister near gas tank). My son still has this Jeep and it's still running well.

 

I bought a Jeep Compass to replace one of the Escapes and a new Grand Cherokee for my wife.

 

There were not many bigger Ford fans around than I was, but it reaches a point of absurdity, and I'm there now. And as Bigblock says above, it's a shame. Ford really did their homework on the NVH of the Edge. It's as tight, smooth, and silent a ride as I've ever experienced. The resale is in the toilet because it's typical Ford major systems failures have become known. If Ford snuffed these problems out early in production instead of making the owners cover the costs, resale on Ford products would be much higher.

 

 

 

John

  • Like 1

Share this post


Link to post
Share on other sites

It is part luck but also maintenance and how you drive the Edge with the 3.5 NA Duratec. I have nearly 600,000 accumulated miles on three Edges with the original water pumps. I do change the coolant often and use full synthetic oil. No proof other than longevity to prove my personal experiences.

 

 

Thanks for the info. My sister has the Edge now and I'll change her coolant before the winter. What brand of coolant have you been using?

 

John

Share this post


Link to post
Share on other sites

None of those vehicles, engines or transmissions are currently in production. There are some problems (water pump on the 3.5, tss/oss sensors on the 6F50 trans, PTUs) but nothing like those older problems and I don't think current Jeeps are that much better.

 

But I guess the grass is always greener....

  • Like 3

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×