PTU & RDU fluid change on 2025 hybrid AWD @ 11,000 miles

[JohnCondren1933]

EDIT: added a pic of my PTU magnet after 11k miles holding a LOT of breakin gunk!

So for my 2nd oil change, I decided to also change the PTU & RDU power takeoff unit & rear differential unit fluid. Went to an independent shop, stay away from chain instant oil changers -- all about fastest money grab job possible

Price-wise, good news & bad news.

The PTU fluid was very dark and magnet had a shitload of breakin gunk (no shiny metal so good).

PTU probably needs to be changed every 3rd oil change, its 75W85 available everywhere cheap, the indy shop charged me $118 to change.

Now the bad, price-wise: I had my RDU rear differential fluid changed, it was not very dark, BUT the 75W-?? fluid is proprietary Ford Motocraft only (Dana probably gets a cut of the 75W Motocraft sales), their Valvoline supplier said no can do, the indy shop had to get it from Ford dealership who charged $50 a quart & needs 1.5 quarts!!

$100 cost of fluids alone, my motor/rdu/ptu fluid change cost about doubled vs without the rdu fluid change.

From this, I think most smart Maverick owners should have their PTU changed every 3rd oil change, my shop it was $110 about double the $65 cost of oil change.

But IMO unless youre towing alot & actually engaging the RDU I dont think its needed more than you change the hybrid drive Mercon ULV fluid, I will probably from here on out only change the RDU when I change the hybrid Mercon ULV every 30,000ish miles.

Unlike the PTU the RDU is not getting heated up by the engine exhaust, as well as generating heat from constant drive torque that the PTU is.

Attached pic is of my PTU drain-plug magnet, that is a LOT of magnetic gunk at 11k miles, good thing magnet is doing its job, but until Im not getting much gunk on the magnet Im gonna be changing that 75W85 PTU every other oil change.

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[Darryl]

So for my 2nd oil change, I decided to also change the PTU & RDU power takeoff unit & rear differential unit fluid. Went to an independent shop, stay away from chain instant oil changers -- all about fastest money grab job possible

Price-wise, good news & bad news.

The PTU fluid was very dark and magnet had a shitload of breakin gunk (no shiny metal so good).
PTU probably needs to be changed every 3rd oil change, its 75W85 available everywhere cheap, the indy shop charged me $118 to change.

Now the bad, price-wise: I had my RDU rear differential fluid changed, it was not very dark, BUT the 75W-?? fluid is proprietary Ford Motocraft only (Dana probably gets a cut of the 75W Motocraft sales), their Valvoline supplier said no can do, the indy shop had to get it from Ford dealership who charged $50 a quart & needs 1.5 quarts!!

$100 cost of fluids alone, my motor/rdu/ptu fluid change cost about doubled vs without the rdu fluid change.

From this, I think most smart Maverick owners should have their PTU changed every 3rd oil change, my shop it was $110 about double the $65 cost of oil change.

But IMO unless youre towing alot & actually engaging the RDU I dont think its needed more than you change the hybrid drive Mercon ULV fluid, I will probably from here on out only change the RDU when I change the hybrid Mercon ULV every 30,000ish miles.

Unlike the PTU the RDU is not getting heated up by the engine exhaust, as well as generating heat from constant drive torque that the PTU is.

It doesn't hurt. But it's probably not necessary. In all honesty, I've very, very, very rarely seen a ptu fail in any Ford vehicle And most people don't really service them. I've seen several RDU failures. Not catastrophic but mostly chatter when turning caused by the internal clutches. So it might be worthwhile to service it periodically.

 

[JohnCondren1933]

1.5 quarts?!! It took less than a quart for mine ...

PS local dealer wanted $123 CAD for the fluid, list price seems to me about $107 CAD for a quart ... Ordered it from rockauto for $38 CAD + $20 for shipping. No idea why Canadian price is so high, maybe Ford made a mistake when converting?

I think you are mixing up fluid volumes for the PTU & RDU.
The PTU using 75W85 that you can buy anywhere, is .4 of a quart for 2000 lb towing Mavs (no PTU intercooler) & .5 of a quart for 4000 lb towing Mavs (also filling PTU intercooler).

The RDU is 100% more than a 1 quart bottle,
get under your Maverick & look at the size volume difference between the RDU & PTU, since your PTu is covered I will attach a picture

 

[Reidles]

Interesting. I did mine at 2000 km and neither took more than a quart. And yes, that one fluid is spendy! But for the diy folks the labour on the rdu is waaaay quicker. Accessing the fill plug on the ptu is a pain in the ass.

 

[SDakota]

I like the 85/90 Royal Purple in the PTU and RDU. On sale it cost me $14.95 ea. and my local shop charge $15.00 ea. to change it.

 

[MarkLally]

The PTU holds no more than 20oz of fluid.
From a video I saw on YouTube, where this guy mounted a go-pro underneath his Ford with the intelligent AWD system, the vehicle ALWAYS starts out in AWD. It disconnects only if the conditions warrant and as you approach what looks to be about 50mph. I can attest from my experience, and how quickly I can take of from a stop while turning, this is definitely the case.

 

[Surly Old Bill]

Isn't the factory recommended replacement schedule for these something like every 100k? Maybe 120k?
I GET doing it early to remove factory assembly gunk, but after that it seems like you'd almost never have to do it again. Unless you're putting a few hundred K miles on your vehicle before trading it in.

 

[Maverick85]

So for my 2nd oil change, I decided to also change the PTU & RDU power takeoff unit & rear differential unit fluid. Went to an independent shop, stay away from chain instant oil changers -- all about fastest money grab job possible

Price-wise, good news & bad news.

The PTU fluid was very dark and magnet had a shitload of breakin gunk (no shiny metal so good).

PTU probably needs to be changed every 3rd oil change, its 75W85 available everywhere cheap, the indy shop charged me $118 to change.

Now the bad, price-wise: I had my RDU rear differential fluid changed, it was not very dark, BUT the 75W-?? fluid is proprietary Ford Motocraft only (Dana probably gets a cut of the 75W Motocraft sales), their Valvoline supplier said no can do, the indy shop had to get it from Ford dealership who charged $50 a quart & needs 1.5 quarts!!

$100 cost of fluids alone, my motor/rdu/ptu fluid change cost about doubled vs without the rdu fluid change.

From this, I think most smart Maverick owners should have their PTU changed every 3rd oil change, my shop it was $110 about double the $65 cost of oil change.

But IMO unless youre towing alot & actually engaging the RDU I dont think its needed more than you change the hybrid drive Mercon ULV fluid, I will probably from here on out only change the RDU when I change the hybrid Mercon ULV every 30,000ish miles.

Unlike the PTU the RDU is not getting heated up by the engine exhaust, as well as generating heat from constant drive torque that the PTU is.

What does PTU and RDU mean?

 

[Ranko Kohime]

What does PTU and RDU mean?

Power Transfer Unit and Rear Differential Unit

 

[b05622]

I purchased my fluids from Rock Auto.

RDU is $27.79 / qt. XY75WQL

PDU is $20.89 / qt. XY75W85QL

Did anyone change their fill and drain plugs on the RDU? The factory service document said to. I imagine it's because there is some sort of thread sealant on the RDU plugs. I reused the old ones.

 

[MarkLally]

I purchased my fluids from Rock Auto.

RDU is $27.79 / qt. XY75WQL

PDU is $20.89 / qt. XY75W85QL

Did anyone change their fill and drain plugs on the RDU? The factory service document said to. I imagine it's because there is some sort of thread sealant on the RDU plugs. I reused the old ones.

I reused the old ones, but I did install new thread sealant.

 

[notfast]

It doesn't hurt. But it's probably not necessary. In all honesty, I've very, very, very rarely seen a ptu fail in any Ford vehicle And most people don't really service them. I've seen several RDU failures. Not catastrophic but mostly chatter when turning caused by the internal clutches. So it might be worthwhile to service it periodically.

Not a whole lot of AWD Fords where you live? The PTUs on Ford D4 platforms fail so often that Dorman has an OE Fix PTU that actually works better (imagine that). Part number is 600-234XD. Engrained in my memory like Warn 38826 to replace those crappy plastic manual lock hubs on '99-04 Super Duties.

 

[Bob The Builder]

Changed my PTU fluid at 8K. Level was fine and the fluid looked good. Moral of the story, YMMV, but you won't know until you change it. I would recommend a nice even number like 10K miles.

 

[Darryl]

Not a whole lot of AWD Fords where you live? The PTUs on Ford D4 platforms fail so often that Dorman has an OE Fix PTU that actually works better (imagine that). Part number is 600-234XD. Engrained in my memory like Warn 38826 to replace those crappy plastic manual lock hubs on '99-04 Super Duties.

There are quite a few. But maybe they're not really put to the test where I live (Tallahassee, Florida) . It's hilly for Florida, but still flat compared to much of the country. And we don't get snow (except for earlier this year but that was a once in a lifetime event) . So I guess the ptu's don't really get a workout. As for the super dutys, we don't have a lot of problems with the locking hubs. We have more problems with vacuum leaks on the backside because of dirt and mud. But most people don't regularly use their 4wd. They only find it doesn't work when they FINALLY need it a couple of years into ownership.

 

[JohnCondren1933]

Thanks for the comment Darryl, appreciate it.

I am however, a bit curious on which Ford vehicles you are referencing for failing RDU but not failing PTU - if this is an "apples to apples" comparison.

As far as the RDU, I dont come from the Ford world but most the RDU on most SUVs -- majority of all FWD-based crossover SUVs -- use a considerably less robust RDU than whats on the Maverick called a "Haldex" or "dual-pump" its basically 2 hydraulic pumps with shared fluid constantly spinning, and only when 1 begins spinning faster than the other from single wheelspin, will that pump begin pressurizing the fluid in the other pump, making the 2 wheels try to synchronize.
Haldex pumps are good for their application which is NOT transferring more than 30% of the motor torque to it, & definitely not putting a hauling or towing load on the Haldex Haldex RDUs are cheap & light, but also light duty & fussy about fluid changes or they go out in very short order!

Now I am not saying the Maverick RDU is a Dana 40 axle by any stretch, but it is an entire hauling class different than anything in most FWD-based crossover SUVs,
Ford Explorer is an exception for FWD-based as far as I know it has an RDU comparable to RWD-level RDU drivetrains like Denali & Suburban.

So if youre talking about a Haldex RDU in my Honda CRV or an Audi & probably also in a Ford Escape vs their PTU, well yeah a Haldex RDU is gonna go out a hell of a lot faster without fluid changes than their PTU no because the PTU is so good, but the PTU is metal gears while the Haldex is just flexible oil-seals sealing a dual-pump fluid.

Maverick is FWD based so most of the time not towing, 100% of the power is being delivered through the PTU gears to the cv joints, the PTU is always both generating heat from torque loads and absorbing heat from the engine exhaust.

The Maverick RDU in comparison is rarely engaging when not fully loaded, even though the driveshaft is free spinning all the time, only when the bed is loaded up or front wheel spin detected.

There are several classes of RDU, most vehicles with an RDU like Maverick has would have be driven by a longitudinal oriented engine like a body on frame RWD based truck, which would not be coupled by the FWD PTU we have on the Maverick but by a heavy duty transfer case.

Similarly, FWD-based vehicles with a PTU like Maverick has, generally have a much lower duty Haldex RDU or spring-loaded clutchpack, of a duty class that will fail within 100k miles if used for sustained hauling or towing loads.

Wish Id remembered to ask for pics of the RDU & PTU fluid as well as the gunk on the PTU magnet, but the service tech said the PTU was very dark,
while the RDU was just slightly darker than new, but still translucent see through.

I commission & program cnc metal cutting automation for Tier 1 automotive manufacturing suppliers, dont optimize the planetary/sun gear robbing & grinding gcode as much as part handling and data tracking but I have optimized logic for 80% of the transmission component manufacturing in vehicles using both ZF & Aisin transmissions & drive-trains.

Unless I am very mistaken on the Mavericks RDU design and the Maverick is using a Haldex dual-pump RDU, there is no drivetrain scenario -- other than some very extreme contrived edge-case done deliberately by someone intimately familiar with the FMEA metrology data on both Maverick RDU & PTU units -- where the Maverick RDU gearsets will experience even a fraction of the cummulative loads, localized heat and wear, of the Maverick PTU gears.

It doesn't hurt. But it's probably not necessary. In all honesty, I've very, very, very rarely seen a ptu fail in any Ford vehicle And most people don't really service them. I've seen several RDU failures. Not catastrophic but mostly chatter when turning caused by the internal clutches. So it might be worthwhile to service it periodically.

It doesn't hurt. But it's probably not necessary. In all honesty, I've very, very, very rarely seen a ptu fail in any Ford vehicle And most people don't really service them. I've seen several RDU failures. Not catastrophic but mostly chatter when turning caused by the internal clutches. So it might be worthwhile to service it periodically.

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