2008 Edge AWD PTU leak

[JohnS]

Noticed black oil spots on the garage floor after a 5 hour (total) road trip. As this was the first indication of a problem, I took it into the Ford Dealership and they told me the PTU is leaking and that the entire unit should probably be replaced--at a cost of $1600. Unfortunately, the car is only a few months and a few thousand miles out of warranty. They did offer to simply replace the seals and fluid as a plan B (and a cost of $400), but didn't recommend this...

 

While researching this topic, I have read that some were successful just replacing the fluid and seals. Was there also a TSB from Ford that suggested this as the first step in fixing the problem?

 

I'm basically trying to get a second opinion from a neutral source. Is it worth the $400 gamble to just replace the fluid and seals?

 

On a side note, I am very disappointed that this problem (of course) arises a mere months after the 5/60000 warranty expired. I understand warranties are just that, and stuff breaks over time, but I am troubled by the fact that this seems to have been a known issue for several years now, yet I have received no guidance from Ford on preventative MX or even some sort of recall.

 

Thank you in advance for any help.

 

John

[WWWPerfA_ZN0W]

Are there any indications of metal shavings in the oil that has leaked out? If not, the very first step to try would be to flush out the PTU, then refill with brand new fluid and see if that helps any. The current fluid is probably way past its' service life and by leaking, it told you it was done! There is also a writeup by the_natrix on adding a drain plug to the PTU to help with the fluid exchange, should you or a trusted mechanic feel comfortable with doing so.

 

Which seals would they replace, specifically? Did they say? Might be worth it, again, IF no metallic particles are seen in the leaking oil.

[JohnS]

Thank you for the reply! They didn't mention anything about metal in the original fluid, but I will ask. I'm also not sure about the seals. Are there any specific ones that would be more cause for concern than the others?

 

I literally took the vehicle in immediately upon noticing the oil spots on the garage floor, so I'm cautiously optimistic that I didn't cause any further damage to the PTU.

 

Thanks again for your time.

 

John

[WWWPerfA_ZN0W]

The commonly replaced seal is the PTU-axle seal which actually leaks transmission fluid (red in color, unless of course it too is burnt). Maybe the seal is leaking just enough not to be notice yet by the owner. If so, that would be good to replace as well.

 

The attached PDF is for a 2011, but should give you an idea. Theoretically, fluid replacement can be done without removing the PTU from the vehicle, just a little slow and tedious. Need a drain pan, fluid pump and new gear oil (75W-140 I believe). Do it a few times over the next year (until you get clear/golden fluid coming out) to make sure you have completely new gear oil in the case. Any competent mechanic should be able to do it.

2011 Ford Edge PTU Input Shaft Seal 308-07B_s7p4776q0.PDF

Ford Edge tsb 09-25-07 SERVICE TIP—POWER TRANSFER UNIT (PTU)—RIGHT HAND INTERMEDIATE SHAFT SEAL LEAKS.pdf

Taurus X PTU section servman.pdf

Edited March 27, 2014 by WWWPerfA_ZN0W

[Waldo]

There are two really quite different failure modes that cause PTU leaks. One is the seals. This is something that happens slowly over time, eventually the seals wear and start to leak. If you go a long time then eventually the PTU ends up with low fluid and can be damaged. Replacing the seals and topping up the fluid should be perfectly fine in this case.

 

The second mode is when the PTU itself overheats, it builds pressure and spits fluid out the vent tube. Replacing the fluid is all you really need to do for this problem, there's not much you can do to keep the PTU cool. If it's overheated enough to cause permanent damage then you will know because the vehicle will feel like it's binding when you make tight turns.

 

If the mechanics are convinced it's the seals and not just coming out the vent tube, then I'd go ahead and replace just the seals but also have new fluid put in the PTU as long as you're not experiencing any binding or strange noises. Another thing you could check is to put the car in the air and turn the front wheels by hand and check that the driveshaft is also turning.