PTU Oil change

[Brian K]

Has anyone changed the oil in their PTU. I have removed the fill plug and sucked out what I could twice. The oil is black and thick. The Workshop Manual says this is normal - but it really does not look like the new 75W140 that I put back in so it is not that normal and clean oil is of course much better than sludge. Also the sludge on the fill plug looks thick. I have considered drilling a hole in the bottom of the PTU and tapping it and installing a plug so the I can properly drain all the oil as shown on Youtube. As it is I don't think I am getting much of the crappy oil out with my sucker hose.

Has anyone done this? It really makes sense to do this and I'd like others comments.

Thanks

[WWWPerfA_ZN0W]

If you are up to it, you can repeat the drain & fill a few times with enough driving in between to warm & mix the old & new fluids. 3 or 4 times should get you pretty close to ultimately having new fluid in the PTU. The fill line is about 1 inch or so below where the fluid starts coming out of the fill plug hole. Initially it can be a very slow, time-consuming, patience-testing, and olfactory-murdering process. The other option is to find a BG shop that will do it for you in 1 go.

 

Not many have tapped a drain hole into the PTU, probably for fear of completely ruining it with metal shavings from the drilling. This would be a great way to allow periodic maintenance though.

[wlepse]

As mentioned above most just do repeated changes till the fluid thins out. But since I just took a look at mine this weekend I have a couple of questions. The drain plug takes a 1/2" square drive from a ratchet right? I couldn't get mine in, maybe it had something to do with the socket retention. Last, what did you use to suck out the fluid?

[WWWPerfA_ZN0W]

3/8" square drive for the fill plug. FSM may mention installing a new plug each time, not sure if people do that tho.

http://www.fordedgeforum.com/topic/10914-ptu-leak-failures/?do=findComment&comment=89533

 

Something like this

http://www.amazon.com/dp/B000CMDPBM/

or this

http://www.amazon.com/dp/B00265M9SS/

or this

http://www.amazon.com/dp/B000GU0MMU/

 

should work. you can also rig your own to a small size shopvac with a reservoir in between if you want to automate.

[Brian K]

Initially I used something similar to a Mityvac 7400 7.3 liter Fluid Evacuator pump that I had for boat oil changes (I tried to copy the Amazon link but It wouldn't copy into this post). Worked well enough but I was concerned about pushing the somewhat rigid and brittle plastic hose into the PTU and having it break off inside. It felt like it almost immediately hit a gear and I had to bend it down to try and direct it to the bottom of the PTU. I tried smaller diameter hose but because the oil was pretty thick, I didn't get much out so used a larger diameter hose. Also I did this with cold fluid because the exhaust pipe is in the way and I didn't want to burn my arms on a hot pipe just to get the fluid warmed up. This made getting a lot of oil out tougher. In the end I drilled and tapped a drain hole (see other posts).

[macbwt]

Change it every 10K miles and you should not suffer any failures.

[Brian K]

Once I get the oil cleaned up (still black after about 7 oil changes) I'll change it every time I change the engine oil. It's up on ramps then anyway and with the drain plug in the PTU, oil changes are a breeze. My philosophy I learned from a friend is 'It's cheaper to change oil than parts'.

[vandentr]

I recently bought a 2008 Edge with 80,000 miles on it BEFORE learning about the PTU issues.

Sufficiently freaked out by all of the horror stories on these things and with the SUV up on ramps I was happy to see that the case was clean and there were no signs of any oil being forced out of the top vent when I inspected it.

I intend to keep it that way, and so these are the steps I have taken so far:

1) I sucked as much of the black, stinky, nasty "oil" out with a hand pump through the unit's fill plug (3/8" ratchet drive) as I could and replaced it with a mixture of 75% 75w-140 gear oil and 25% Mercon V transmission fluid.

2) Drove the vehicle about 50 miles on that mixture.

3) Sucked the thinned mixture out.

4) Removed the heat shield mounted to the transmission torque mount (10mm nuts).

5) Obtained 1/8" and 5/16" cobalt bits and a 9/16" steel bit and proceeded to s-l-o-w-l-y drill out the bottom-center of the case in steps using WD-40 as a cutting lubricant.

6) After drilling through the case I allowed the remaining oil to drain out and sprayed about 1/4 of a can of brake cleaner through the fill hole and then another 1/4 of a can through the newly drilled hole to wash out as much of the drilling debris as possible.

7) Used a 3/8" NPT tap to thread the hole with a 6" extension and a 16mm socket to drive the tap.
Note: Once the tap started to cut I only used 1/2 turns to prevent binding. After each 1/2 turn I backed the tap out, cleaned it off with brake cleaner, sprayed WD40 into the hole to wash out any chips, and then proceeded to thread it back in by hand and make another 1/2 cutting turn.

8) After completing the tapping process I screwed a hex fill plug into my new drain hole and hand pumped as much mineral spirits as I could into the case and let it sit for a couple of hours.

9) Unscrewed the drain plug and let the mineral spirits rush out, washing any of the remaining debris out with it.

10) Sprayed another 1/2 can of brake clean into the case to rinse off any left over mineral spirits out of the case.

11) Refilled case with Royal Purple 75w-140 and closed and cleaned everything up.

I'll drive it around for a while now before rechecking the contamination level, but so far so good.

[WWWPerfA_ZN0W]

Great list

 

I WOULD have added a Step 10.5 to first add Motorcraft or cheapo 75W140 to carry away any remnants of brake cleaner/minerals spirits, driven around 50 miles, then final change to Step 11.

 

BUT, interested in your findings, and good luck!

[drs120new]

So, I had a similar problem to the folks here. PTU belching out black blobs of grease all over my driveway. I drilled and installed a drain plug and flushed the PTU out and refilled. The car was riding great and the dripping and smell ceased. After 2 weeks I decided to drain it out again, the oil was still filthy, and within 3 days the PTU started to belch out bigger blobs of oil/grease. This has been intermittent. I'd like to know what your take on this is. Is the vent still periodically getting clogged? Should I flush it a third time. I am getting frustrated and the driveway is looking like a spotted leopard.

[WWWPerfA_ZN0W]

You need to do the "flush" at least 3/4 times in a row at very short intervals to get it looking/running good. Plus do not allow the PTU to submerge. Were there metallic particles in the PTU? Have you checked to see if maybe trans fluid is leaking into the PTU?

[enigma-2]

One other thing to remember with a unit this old. When you next change to PTU check the seal; make certain that it's not leaking. The dealer found my 09 MKX leaking at ~95k & had it repaired under warranty. They told me they thought that when the PTU seal leaks, it gets low on fluid and what's left gets too hot and turns gummy. At thid point it doesn't lubricate PTU properly and the unit fails.

[chefduane]

Hey MacT, you're going 10k miles on the PTU oil changes? I was thinking 20k would be sufficient? Fortunately when I had my shop change it (at I assume the first change since I bought it at 65k miles) they said the fluid was still flowing nicely and there were no black globs in the vent tube. Hopefully I got lucky!!

[WWWPerfA_ZN0W]

Personally, since you do live in a hot part of the country, I would at least inspect every year. If you can change it every year, even better. IF the fluid remains freeflowing each time, 3/36 would be a good rule of thumb for change. Assuming nothing happens on a regular basis that would qualify for Special Operating Conditions.

 

A sample sent to Blackstone would let you know where you stand wrt PTU health.

[macbwt]

The key is awareness. Frequent checking and monitoring of the PTU fluid. Heavy use would require frequent fluid changes. Environmental conditions also play a part along with how long you idle as the heat just starts to cook the fluid. I would start at 10K fluid changes and then test. then go 15K and test. You want to look for that acceptable point. Just like I find with engine oil. Even the synthetics have a point of failure based on how the vehicle is used.

 

Hey MacT, you're going 10k miles on the PTU oil changes? I was thinking 20k would be sufficient? Fortunately when I had my shop change it (at I assume the first change since I bought it at 65k miles) they said the fluid was still flowing nicely and there were no black globs in the vent tube. Hopefully I got lucky!!

[enigma-2]

When I had my local dealer change the flid the first time, I talked the the mechanic who they considered their expert on these units.

 

He told me that he would recommend changing the fluid every 30k miles unless I was towing a trailer or running off road. Under those circumstances he recommended every 20k.

[WWWPerfA_ZN0W]

Circumstances, and the starting point, will dictate the schedule. If you start with known good fluid, that is what the service intervals are useful for. If you are trying to resolve an existing problem, then always think in terms of Special Operating Conditions, ie, stricter/shorter schedules.

[drs120new]

Thanks for your reply WWWPerfA_ZN0W. There were no metal particles and trans fluid, but I think I filled it to where the fluid was just coming out of the fill hole. If this was too high, then maybe the pressure made some come out of the vent. Time will tell. One question for you. What do you mean by don't allow the PTU to submerge?

[WWWPerfA_ZN0W]

As per the owner manual, the PTU should not be submerged in water, i.e., do not drive the Edge through highwater/standing water conditions. FWD would be OK, but not AWD in such circumstances. Water could enter the PTU, contaminate the oil, and ruin the PTU.

[omar302]

As per the owner manual, the PTU should not be submerged in water, i.e., do not drive the Edge through highwater/standing water conditions. FWD would be OK, but not AWD in such circumstances. Water could enter the PTU, contaminate the oil, and ruin the PTU.

 

If water is that high, I think it could also damage all wheel bearings & the rear diff (AWD). So it would still be a no go regardless of AWD or FWD.

[drs120new]

Thanks for the reply. Our 2007 MKX has never been submerged in water. The deepest puddle we went through was maybe 6 inches. Anyhow, I think I am going to flush the PTU again and refill. Is there any suggestions on how to clean the vent other the flushing 3-4 times?

[enigma-2]

Rear different is also mentioned, don't know about the bearings.

[drs120new]

I do have a question for you WWWPerfA_ZN0W. Is there a way to clean the actual vent? Our MKX is still leaking the PTU fluid all over our driveway and garage. The fluid is not as foul as the first time it started however. Would overfilling the PTU (in my case to the bottom of the fill plug) blowout any other seals? Or do you think it is still coming out of the vent. This is SO frustrating, since it didn't leak a drop after I flushed it the first time. The second drain/flush 2 weeks later seems to have done me in. Appreciate any advice you have at this point.

[enigma-2]

Did you check the integrity of the seal?

[WWWPerfA_ZN0W]

The vent (AFAIK) CAN be removed, but IDK about putting a new vent on or replacing the old vent. Someone on this forum may have done it though, I will have to look. If you do take the vent off, it might be possible to retrofit a Taurus vent extension kit on there so it ends in the engine bay and the risk of submersion is greatly reduced.