What are the signs the Power Transfer Unit (PTU) is failing

[Professor_Tomorrow]

My Explorer is a 2015 XLT AWD with 120,000 miles. On hard acceleration mainly going uphill there is a strange burning smell. It almost seems like bread baking at Subway.

I read that this was 'normal' smell coming from the PTU vent. It does seem to be worse when pulling a trailer. I looked at changing the gear oil, but of course mine is a sealed unit. I watched Brian at Ford Tech Makuloco demonstrate how to change it without a drain plug. It looks pretty complicated.

I'd like to just have the PTU changed out with one that has a drain and fill plug.
1. Is there and OEM Ford/Motorcraft updated PTU with a fill and drain plug? I know Dorman makes one.
2. I'm not a fan of 'fixing things that aren't broken.'
3. My concern is what indications does a failing/failed PTU present? Does it even give any signs or does it just stop working?
4. If it stops working does the vehicle become unsafe and undrivable?

Thanks,

 

[peterk9]

Several reports mention that a failing PTU will generate a propane-type or natural gas odour. You may hear grinding noises and or shuttering on take-off.
It can cause transmission damage if it seizes while driving.
I don't know if the PTUs that are now available have a drain or not.

Original 2007-2016 Ford Transfer Case AT4Z-7251-G | Levittown Ford Parts

2007-2016 Ford part # AT4Z-7251-G - Transfer Case

parts.levittownfordparts.com

Levittown Ford is a forum vendor and offers members a discount. Coupon Codes for Forum Members

Peter

 

[onestout]

I just added a drain plug to my PTU....not hard, drill a hole, tap for a plug, screw in plug. A lot easier and cheaper than putting in a different PTU.

 

[BrettS.]

Usually the PTUs fail due to insufficient lubrication and the bearings inside fail. Specifically the bearing that mounts in the case which takes out the case and makes it impossible to rebuild. Find a way to regularly change the fluid or it will fail.

 

[StormTrooperExplorer]

I just added a drain plug to my PTU....not hard, drill a hole, tap for a plug, screw in plug. A lot easier and cheaper than putting in a different PTU.

Where did you drill the hole at?

 

[onestout]

there is video on youtube or this site that I went by but you can sort of figure it out just by looking at it where it needs to be. You want to drill in between the gears so you don't hit them. I think I used a 1/4" plug but you don't need one that big, just makes it a little more difficult to tap. The pics/video I found had some rough dimensions of about where to put it.....pretty sure it is on this site somewhere also.

 

[J_C]

Here's a video example, for hole location and more info about fill options.

 

[onestout]

one bit of advice since there are a lot of videos out there on how to do this....use a tapered pipe plug....do not use a straight threaded drain plug. There is no machined surface for it to seal on, you want the threads to do the sealing since you will be using a hand drill for this.

 

[J_C]

Do you think something like Permatex high temp thread sealant would be the best choice?

https://www.amazon.com/Permatex-59235-Temperature-Thread-Sealant/dp/B000AAJTYS?tag=seriouexplor-20

One thing I wondered about was putting in a valve instead, like a fumoto style often used on oil pans.

Buy Fumoto® Valve Online | Replace Oil Drain Plug

By simply replacing your stock oil drain plug, you can drain your engine oil without tools or mess. Trusted by over 10 million satisfied customers, the original Fumoto Engine Oil Drain Valve continues to offer individuals, truck owners, marine engine mechanics, and industrial engine maintenance...

www.fumotousa.com

 

[onestout]

not something I would ever do, stick with a tapered plug, they will give you the best seal without having to remove the ptu and machine a flat onto the outside of the case.

 

[peterk9]

Since the OP hasn't replied to any posts so far, I'd suggest he find out if the PTU is still serviceable before going ahead with any drilling for a drain plug. If the PTU is 'toast', that would be a lot of wasted effort. It seems the issue has been going on for a while.

Peter

 

[Professor_Tomorrow]

Since the OP hasn't replied to any posts so far, I'd suggest he find out if the PTU is still serviceable before going ahead with any drilling for a drain plug. If the PTU is 'toast', that would be a lot of wasted effort. It seems the issue has been going on for a while.

Peter

I was going to 'change the fluid' via the vent tube, but I ended up taking the Explorer to a local shop for weeping seal I mentioned in another post. That thread received zero responses. The shop replaced the seals, which required emptying the fluid, so it was changed at the same time.

My Explorer is a 2015 XLT AWD with 120,000 miles. On hard acceleration mainly going uphill there is a strange burning smell. It almost seems like bread baking at Subway.

I read that this was 'normal' smell coming from the PTU vent. It does seem to be worse when pulling a trailer. I looked at changing the gear oil, but of course mine is a sealed unit. I watched Brian at Ford Tech Makuloco demonstrate how to change it without a drain plug. It looks pretty complicated.

I'd like to just have the PTU changed out with one that has a drain and fill plug.
1. Is there and OEM Ford/Motorcraft updated PTU with a fill and drain plug? I know Dorman makes one.
2. I'm not a fan of 'fixing things that aren't broken.'
3. My concern is what indications does a failing/failed PTU present? Does it even give any signs or does it just stop working?
4. If it stops working does the vehicle become unsafe and undrivable?

Thanks,

I appreciate the responses, but I never received an answer about collateral damage or other PTU options. Since the vehicle is 10 years old, I'm gonna wait until it fails.

 

[BrettS.]

I highly recommend changing the PTU fluid regularly if you want it to last. I do it with every other oil change. It is not a "lifetime fill" aka until the warranty runs out. The small quantity of fluid combined with the severe environment leads to fast degradation of the gear oil. Some of the PTUs, like in the PIU, have a drain port. You can also install one. Its not hard. Buy a 1/8" NPT drill and tap set on Amazon. Drill the hole and catch the fluid. Once empty run the tap to thread the hole. Buy a 1/8" NPT drain plug with magnet. There is a nice stainless steel one on Amazon. I used a long q-tip to clean out the hole and make sure I got all the metal shavings out. (I found I didn't have any up in the case, they all dropped down as I was drilling and tapping.) Then use pipe sealant to seal the drain plug every time. Don't overtighen. Just to snug. We only need to seal the threads to prevent a leak. The more you crank down on it the more you open up the threads each time and further in the drain plug will go. Then buy a longer vent hose so you can fill from the engine compartment. Buy a large syringe on Amazon to fill. I found the easiest/quickest method to fill the syringe halfway, insert into hose, pull back syringe to create vacuum, then push the fluid down into the PTU. I fill 100cc at a time. If you try to drip it into the hose it usually hydrolocks or it will burb air and splatter oil out the funnel. It also takes forever. Lastly check the vent itself to make sure if works. Mine was so clogged up no air would go through. I disassembled mine and put a new cotton ball in to replace the cotton in mine. It was all gunked up and packed inside.

 

[lolford]

I was going to 'change the fluid' via the vent tube, but I ended up taking the Explorer to a local shop for weeping seal I mentioned in another post. That thread received zero responses. The shop replaced the seals, which required emptying the fluid, so it was changed at the same time.


I appreciate the responses, but I never received an answer about collateral damage or other PTU options. Since the vehicle is 10 years old, I'm gonna wait until it fails.

what was the cost for that job?