PTU and Rear Differential (RDU) fill plug access (N/A V6 AWD)

[metroplex]

I have a 2018 XLT AWD w/ the N/A 3.5 V6, so the PTU only has a fill plug.

Does anyone have any tips on accessing the fill plug of the PTU and RDU? It seems I can get my 3/8" ratchet in there but there doesn't seem to be a lot of room to remove the plugs and the ratchet together. Do I access the PTU from the engine oil pan drain plug area? Seems to be the only way.
For the RDU, it seems I can get in from only one area.
Should I park the vehicle facing slightly downhill so I can get a bit more new fluid back in? Luckily I can crawl under the vehicle without the need for ramps or jacks due to the ground clearance.

 

[peterk9]

There are several threads on changing the PTU fluid. Have you checked them out?

Peter

 

[metroplex]

Yes. And didn't find the info I wanted. Mostly talked about the PTUs with coolers that have a drain plug, which is worthless to me as I don't have a drain plug on mine. Just wanted simple tips on what tools they used to access the fill plugs, not a step-by-step on everything else.

 

[FEMC]

U need a fluid extractor with a flexible small diameter hose. It’s a real PITA. See if a dealer will do it for u. To remove the PDU fill plug on my 2016 I used low profile 16 inch ratchet. Only about 20 ounces in there.

 

[MattMPA]

First, the RDU. I used a serpentine belt wrench and a air powered brake bleeder. The serpentine belt wrench fits between the rear and crossmember easily.

The PTU. I have a '16 Interceptor Utilty, which does have a drain plug, but a difficult to access fill plug....so I extended the vent. My former '18 SHO had just the fill plug, and I'd bet your Explorer is the same. You'll need the same air powered brake bleeder type tool to remove the fluid. Using a thin piece of hose, stuck into the fill hole. I only ever was able to get out about 12 ounces this way, but it was easy enough that I changed the PTU with each oil change until the fluid looked ok. Filling is done with one of those bottle top pumps that you can get at auto parts stores or Walmart..usually for marine engines.

Anyhow...here's the hot tip for removing the fill plug. It's a standard 3/8 plug, so you use a 3/8 ratchet of extension. With a couple long extensions, you should be able to slide them in from the front passenger wheel area and straight into the plug. At least with the SHO...that shares a platform with the Explorer...this was easy. Your ratchet will work from the wheel house area.

 

[FEMC]

Can you share a picture of extractor that you used?Here is what I used. I think using a latex hose would work better cause it so tight. I like the idea of serpentine tool. That is great idea. They are 15 bucks at HR. Again a low profile 16 inch length ratchet also worked well.

ALEKO OEXP02 1.6 Liter Oil and Fluid Extractor Pump For Automotive Fluids

 

[MattMPA]

Can you share a picture of extractor that you used?Here is what I used. I think using a latex hose would work better cause it so tight. I like the idea of serpentine tool. That is great idea. They are 15 bucks at HR. Again a low profile 16 inch length ratchet also worked well.

ALEKO OEXP02 1.6 Liter Oil and Fluid Extractor Pump For Automotive Fluids

I used a thin piece of vinyl tube, like would hook up to an oxygen machine adapted to fit the tube on the tool. I've placed a link for a machine similar to mine. Uses compressed air. We tried a hand powered Mityvac, but it doesn't draw hard enough...

Capri Tools Vacuum Brake Bleeder CP21029

Brake bleeder works by using compressed air for the built-in venturi system and produces a vacuum to bleed and flush the hydraulic brakes and clutches. Set includes 1 piece of 40 in. silicon hose with

www.homedepot.com

 

[peterk9]

Please clarify the term RDU. Thanks.

 

[MattMPA]

Please clarify the term RDU. Thanks.

Rear Differential Unit

 

[peterk9]

Thanks Matt. Just wanted to make sure it wasn't something else.

Peter

 

[metroplex]

Please clarify the term RDU. Thanks.

Standard term for the rear drive unit. But it's basically the rear differential.

 

[metroplex]

First, the RDU. I used a serpentine belt wrench and a air powered brake bleeder. The serpentine belt wrench fits between the rear and crossmember easily.

The PTU. I have a '16 Interceptor Utilty, which does have a drain plug, but a difficult to access fill plug....so I extended the vent. My former '18 SHO had just the fill plug, and I'd bet your Explorer is the same. You'll need the same air powered brake bleeder type tool to remove the fluid. Using a thin piece of hose, stuck into the fill hole. I only ever was able to get out about 12 ounces this way, but it was easy enough that I changed the PTU with each oil change until the fluid looked ok. Filling is done with one of those bottle top pumps that you can get at auto parts stores or Walmart..usually for marine engines.

Anyhow...here's the hot tip for removing the fill plug. It's a standard 3/8 plug, so you use a 3/8 ratchet of extension. With a couple long extensions, you should be able to slide them in from the front passenger wheel area and straight into the plug. At least with the SHO...that shares a platform with the Explorer...this was easy. Your ratchet will work from the wheel house area.

Thanks, so it's doable with a thin 3/8" drive.

I looked over my notes for my 2014 SHO and I used a Gear Wrench pass-thru. I just bought a Powerbuilt Slim ratchet and its about 30% thinner than that, which was already thin. I cannot access the fill plug from the wheel house area, it's blocked by the catalytic converter. My 2014 SHO plug was visible from the wheel.

I used a hand pump for my SHO and it was a messy PITA. I'm going to use the OEMTools pneumatic/manual extractor this time around.
I may need to get a new pump for the fresh fluid though.

 

[peterk9]

Standard term for the rear drive unit. But it's basically the rear differential.

Thanks. Have updated the thread title for Search purposes.

Peter

 

[metroplex]

Thanks. Have updated the thread title for Search purposes.

Peter

Ok, but FYSA it's not "rear differential unit". It's the Rear Drive Unit and the RDU acronym is common knowledge among the Ford forums/communities.

 

[peterk9]

Ok, but FYSA it's not "rear differential unit". It's the Rear Drive Unit and the RDU acronym is common knowledge among the Ford forums/communities.

Thank you. Did a Search on RDU and only 1 member has previously used that term whereas Differential shows up in multiple threads/posts.
The thing to keep in mind is that not everyone on these forums is familiar with all the acronyms commonly used by those more experienced members.

Peter

 

[metroplex]

Thank you. Did a Search on RDU and only 1 member has previously used that term whereas Differential shows up in multiple threads/posts.
The thing to keep in mind is that not everyone on these forums is familiar with all the acronyms commonly used by those more experienced members.

Peter

Thanks.

Forums were the hot thing to use for the past 10-15 years, but more recently if you go on the Facebook groups, RDU is thrown around left and right on multiple Ford groups including 11-19 Explorers. I just did a search on one of the bigger groups and numerous hits came up. I haven't checked Reddit but I'm sure its the same way.

 

[funwithbono]

I have a 2018 XLT AWD w/ the N/A 3.5 V6, so the PTU only has a fill plug.

Does anyone have any tips on accessing the fill plug of the PTU and RDU? It seems I can get my 3/8" ratchet in there but there doesn't seem to be a lot of room to remove the plugs and the ratchet together. Do I access the PTU from the engine oil pan drain plug area? Seems to be the only way.
For the RDU, it seems I can get in from only one area.
Should I park the vehicle facing slightly downhill so I can get a bit more new fluid back in? Luckily I can crawl under the vehicle without the need for ramps or jacks due to the ground

I have a 2018 XLT AWD w/ the N/A 3.5 V6, so the PTU only has a fill plug.

Does anyone have any tips on accessing the fill plug of the PTU and RDU? It seems I can get my 3/8" ratchet in there but there doesn't seem to be a lot of room to remove the plugs and the ratchet together. Do I access the PTU from the engine oil pan drain plug area? Seems to be the only way.
For the RDU, it seems I can get in from only one area.
Should I park the vehicle facing slightly downhill so I can get a bit more new fluid back in? Luckily I can crawl under the vehicle without the need for ramps or jacks due to the ground clearance.

I have a 16 sport ecoboost so not sure if your PTU is the same. Drain plug is on the lower right side (underneath) of the PTU. I use a 1/4” stubby Allen socket (sunex) and a flexible 1/4” ratchet with no problem. This is for draining only. I fill from the top using the extension modification which is already posted on this forum. For the rear dif, I pump it out from the top with a simple hand pump and reverse the process for fill (until it starts to drip)…then replace drain plug. I’m using redline 75w/140 in the PTU and 75w90 in the diff. Almost 200,000 miles on my dif and PTU; all is groovy!

 

[metroplex]

I have a 16 sport ecoboost so not sure if your PTU is the same. Drain plug is on the lower right side (underneath) of the PTU. I use a 1/4” stubby Allen socket (sunex) and a flexible 1/4” ratchet with no problem. This is for draining only. I fill from the top using the extension modification which is already posted on this forum. For the rear dif, I pump it out from the top with a simple hand pump and reverse the process for fill (until it starts to drip)…then replace drain plug. I’m using redline 75w/140 in the PTU and 75w90 in the diff. Almost 200,000 miles on my dif and PTU; all is groovy!

View attachment 429045 View attachment 429046 View attachment 429047

The PTU's are different. The ones with coolers (Ex Sport/Platinum, Police Interceptor) have a drain plug, and the temp sender is the official fill port location but people choose to use the vent. The ones without coolers (Base, XLT, Limited factory units) use a fill plug only. The Ford replacement units started to come with drain plugs from what I saw.

Did you use a 1/4" drive for the RDU fill plug? I thought it was a 3/8" square drive.

 

[funwithbono]

The PTU's are different. The ones with coolers (Ex Sport/Platinum, Police Interceptor) have a drain plug, and the temp sender is the official fill port location but people choose to use the vent. The ones without coolers (Base, XLT, Limited factory units) use a fill plug only. The Ford replacement units started to come with drain plugs from what I saw.

Did you use a 1/4" drive for the RDU fill plug? I thought it was a 3/8" square drive.

I used the 1/4” stubby allen socket (sunex) for the PTU (my ‘16 does not have a cooler or fill plug btw, but I take extreme care of it, thus the vent conversion/extension); and you are correct regarding the 3/8” sq drive for the RDU.
-cheers

 

[metroplex]

I used the 1/4” stubby allen socket (sunex) for the PTU (my ‘16 does not have a cooler or fill plug btw, but I take extreme care of it, thus the vent conversion/extension); and you are correct regarding the 3/8” sq drive for the RDU.
-cheers

Your 2016 Explorer Sport would have the PTU cooler. Do you not see a module on the passenger side of the PTU right above the drain plug with two coolant hoses running into it? There is also a temperature sensor that is the official fill plug for that PTU but it is difficult to access, hence the use of the vent/extension.

It'd be weird if you didn't have the cooler and had the drain plug. Thst meant it's a replacement PTU without a cooler for an application that uses a cooler.