PTU and RDU fluid spec sheets

[FrigateOrpheon]

Hello all,

New to the forum and Bronco Sport ownership. Picked up a 21 Badlands and started doing my due diligence on digging for common maintenance items not specified in the owners manual. I came from first gen Mini Cooper ownership so wrenching is something I'm not a stranger to at all.

PTU and RDU fluid changes seemed to be a common occurrence across a lot of Ford models so I went ahead and did the entire drive line shortly after getting the vehicle. But figuring out the correct fluid for the RDU was a bit of a pain, so I figured I would make this thread to help anyone in the future looking for similar advice.

I've attached images of spec sheets for both the PTU and RDU that I got from a local dealer. My uncle works as the head of the parts department there so I asked him to see what was officially recommended and this is what I got.

Some side notes and personal experiences from doing this myself: I see a bunch of people adding the XL-3 friction modifier to the bottle of RDU fluid prior to refilling. I didn't do this for a couple reasons. 1. It is not called for on any official documentation I have seen, including the sheet I got from the dealer. 2. The bottle of XY-75W-QL states that there are friction modifiers already formulated in it, so to me it seems like adding more is unnecessary and potentially harmful. You may do what you wish with this information.

Also for the Badlands (or any model with the 2.0) I have seen people suggesting that draining the PTU needs to be done with a fluid extractor due to the lack of a dedicated drain plug. While this does work I'm sure, for me a much easier way was to just remove the oil cooler and drain that way. It's held on by two 8mm stud bolts and while getting at them is a pain to be sure, I found that a 1/4 inch socket wrench, deep well socket, and a small swivel extension made the job very easy. Not to mention you're more likely to get a better fluid exchange that way.

Anyway that's my .02, thanks for coming to my TED talk. Looking forward to being a part of the community!

 

[Dude]

Hello all,

New to the forum and Bronco Sport ownership. Picked up a 21 Badlands and started doing my due diligence on digging for common maintenance items not specified in the owners manual. I came from first gen Mini Cooper ownership so wrenching is something I'm not a stranger to at all.

PTU and RDU fluid changes seemed to be a common occurrence across a lot of Ford models so I went ahead and did the entire drive line shortly after getting the vehicle. But figuring out the correct fluid for the RDU was a bit of a pain, so I figured I would make this thread to help anyone in the future looking for similar advice.

I've attached images of spec sheets for both the PTU and RDU that I got from a local dealer. My uncle works as the head of the parts department there so I asked him to see what was officially recommended and this is what I got.

Some side notes and personal experiences from doing this myself: I see a bunch of people adding the XL-3 friction modifier to the bottle of RDU fluid prior to refilling. I didn't do this for a couple reasons. 1. It is not called for on any official documentation I have seen, including the sheet I got from the dealer. 2. The bottle of XY-75W-QL states that there are friction modifiers already formulated in it, so to me it seems like adding more is unnecessary and potentially harmful. You may do what you wish with this information.

Also for the Badlands (or any model with the 2.0) I have seen people suggesting that draining the PTU needs to be done with a fluid extractor due to the lack of a dedicated drain plug. While this does work I'm sure, for me a much easier way was to just remove the oil cooler and drain that way. It's held on by two 8mm stud bolts and while getting at them is a pain to be sure, I found that a 1/4 inch socket wrench, deep well socket, and a small swivel extension made the job very easy. Not to mention you're more likely to get a better fluid exchange that way.

Anyway that's my .02, thanks for coming to my TED talk. Looking forward to being a part of the community!

Thank! Any videos on your PTU and RDU fluid change procedure?

 

[FrigateOrpheon]

Thank! Any videos on your PTU and RDU fluid change procedure?

Unfortunately no. It was 90+ degrees out when I was doing it so I was just focused on getting through the job It is relatively straightforward though.

The RDU is just a 3/8" square drive drain plug on the bottom of the diff and a matching fill plug toward the top. No jack or removal of any parts are necessary. Just drain and fill until fluid starts coming out the fill plug then cap it off. Space is limited to get to the fill plug but I was able to get my ratchet in there and work it free without too much fuss.

The PTU is a little more involved. Jack the truck up, take off the passenger wheel, remove skid plate to gain access. Then remove the aforementioned PTU cooler to drain and replace when fluid stops coming out. Fill plug is a 8mm hex drive on this one. Again fill until fluid seeps out and plug it back up.

Another forum user did post this video for the PTU (I believe he also has one for the RDU) and it helps point out the parts in question.

 

[beaudointl]

Good on you for changing those fluids, very important for the life of those units. Add nothing to the RDU fluid. It is specifically formulated for the clutches in those units and need nothing else. There is an improved vent hose for some 21 Sports (TSB). It goes a little higher in the rear passenger wheel well and has an elbow to prevent contamination of the RDU. If you're doesn't have it I would recommend installing it. Most 22's and up already have this improved vent. Just something to consider.

 

[FrigateOrpheon]

Good on you for changing those fluids, very important for the life of those units. Add nothing to the RDU fluid. It is specifically formulated for the clutches in those units and need nothing else. There is an improved vent hose for some 21 Sports (TSB). It goes a little higher in the rear passenger wheel well and has an elbow to prevent contamination of the RDU. If you're doesn't have it I would recommend installing it. Most 22's and up already have this improved vent. Just something to consider.

I've heard talk of this vent hose but haven't checked to see if mine has had it installed yet or not. I'll look into it this weekend. I will say that the fluid that came out of the RDU did look pretty clean all things considered. But that doesn't mean that the improved vent is necessarily installed. I do plan on getting it off the pavement before too long so any improvements to reliability I'm all ears about.

That being said, is it pretty easy to tell the difference between the two? Like will I know if it has it or not just by looking and having no point of reference?

 

[beaudointl]

If you look up TSB 24-2185 it shows and tells you everything you need to know. If you can't find it, let me know and I will try and save a copy from service data and upload it

 

[Dude]

If you look up TSB 24-2185 it shows and tells you everything you need to know. If you can't find it, let me know and I will try and save a copy from service data and upload it

Pic showing RDU vent hose is:
https://static.oemdtc.com/NHTSA-PDFs/MC-11010795-0001.pdf

There is also TSB 25-2351 RDU TECHNICAL SERVICE BULLETIN Chatter/Shudder During Low Speed Turning Events

https://www.broncosportforum.com/forum/threads/new-tsb-25-2351-rdu-technical-service-bulletin-chatter-shudder-during-low-speed-turning-events.16807/

 

[beaudointl]

Yes, that is the latest version. Same wrt the vent hose.

 

[beaudointl]

I've heard talk of this vent hose but haven't checked to see if mine has had it installed yet or not. I'll look into it this weekend. I will say that the fluid that came out of the RDU did look pretty clean all things considered. But that doesn't mean that the improved vent is necessarily installed. I do plan on getting it off the pavement before too long so any improvements to reliability I'm all ears about.

That being said, is it pretty easy to tell the difference between the two? Like will I know if it has it or not just by looking and having no point of reference?

This is the updated vent hose part number.

 

[FrigateOrpheon]

Thanks everyone, this is seriously helpful knowledge. I'll take a look at it this weekend to see which one is installed. If it turns out to be the older version (as I suspect it will be) then the updated one will be next on my list of things to do.

It looks like a fairly straightforward job, has anyone done this themselves? Drilling holes into the wheel well would make me sweat a little.

 

[bozer]

Also for the Badlands (or any model with the 2.0) I have seen people suggesting that draining the PTU needs to be done with a fluid extractor due to the lack of a dedicated drain plug. While this does work I'm sure, for me a much easier way was to just remove the oil cooler and drain that way. It's held on by two 8mm stud bolts and while getting at them is a pain to be sure, I found that a 1/4 inch socket wrench, deep well socket, and a small swivel extension made the job very easy. Not to mention you're more likely to get a better fluid exchange that way.

When you remove the two 8mm stud bolts do you just pull back the oil cooler a couple of inches, let the fluid drain and then position the cooler back in place? Do you need to replace any gaskets or stud bolts?

 

[beaudointl]

Thanks everyone, this is seriously helpful knowledge. I'll take a look at it this weekend to see which one is installed. If it turns out to be the older version (as I suspect it will be) then the updated one will be next on my list of things to do.

It looks like a fairly straightforward job, has anyone done this themselves? Drilling holes into the wheel well would make me sweat a little.

I have done a few, just put a drill stop on the bit about a 1/4-3/8" from the tip. Ford has a stud sert that requires a special tool to mount the extended part of the vent hose. You could use a 1/4-20 but sert or something similar.

 

[FrigateOrpheon]

When you remove the two 8mm stud bolts do you just pull back the oil cooler a couple of inches, let the fluid drain and then position the cooler back in place? Do you need to replace any gaskets or stud bolts?

Correct. The cooler doesn't even need to come all the way out. Just enough to let the fluid drain. And the cooler is sealed by an o-ring. I saw no need to replace it, and you likely wont either. The only reason I could see replacing it is if it were damaged or leaking. As for the stud bolts, they are not torqued down very tight at all. I dont have the spec, but I would guess 20 or so ft lbs. They are very much reusable.

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