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Hey MTC,
There are a number of posts on here about the poor PTU/RDU fluids & wear from the factory and I wanted to add some fuel to the flame. I changed mine at ~13,000 miles and it was not in good shape (see pictures below). The PTU definitely seemed underfilled, had metallic debris, and a ton of sludge on the magnetic drain plug. The process was pretty simple, and definitely something you should do as part of your break-in fluid changes or with your first oil change (ideally before 5k miles).
You can also see some examples of higher mileage Mavericks that are already hitting transmission trouble. Daniel Deliverz has a great YouTube channel on the Mav (check it out here)and his blew at ~85,000 miles! (turns out this may not have been a blown transmission, but there is still a ton of gunk in these units.) He ran what I'd call "medium" duty, and hadn't swapped any trans fluids.
Simple explanation: a PTU (Power Transfer Unit) and RDU (Rear Drive Unit) are what transfer the engine & axial rotation that runs along the car, out sideways to power both wheels. Only the AWD version will have an RDU as they power all 4 wheels.
The Problem: In the Mav, the PTU is in a spot that sees a lot of heat from the engine/exhaust (causing oil to break down faster) and a lot of owners are reporting their trucks are coming from the factory with lower levers of oil. Both PTU & RDU systems are also always spinning, even if they aren't being powered. Meaning, they constantly need oil to stay lubricated, no matter if you're only running the front wheels, just doing normal driving, or idling (I think) . Plus, I saw a good amount of fine metallic debris/sludge that will create increased wear over time since there really isn't a filter in either unit (just a magnet). This is even more critical if you plan on towing or doing lots of "truck" stuff.
If you want your truck to last, change these oils ASAP!
How-to: There is already a great YouTube video on this by Dad's Garage that covers all the steps. This 1 is for the PTU and this 1 for the RDU. I don't have a lift, but was still able to do it with a jack & jack stands. Main difference is keeping the truck more-or-less level; so try not to jack it up too high. Also, make sure to pick-up an oil pump (something like this) as it will be near impossible to get the new oil in without it. I used OEM Motorcraft 75W Disconnect Rear Drive Unit Fluid (XY75WQL) for the RDU and Red Line 50104 75W85 GL-5 (Amazon) for the PTU. A lot of people recommend sticking with OEM for both, but I've had a lot of success in high heat applications using Red Line oil on my 2-stroke. Ultimately it's your call, but these fluids are OEM for good reason. You shouldn't need any additives as both motorcraft and red line already include the "friction modifiers" and such. Additionally, I wouldn't change to any other weight oil as these are very low volume systems that are engineered to perform a very specific way.
1. Remove the Fill Plugs: After you jack up the car, remove the FILL plug first. This prevents you being stranded if you can't get it off after draining. You'll need an 8 mm hex for the PTU plug and a pretty long ~10" extender. The RTU is the 3/8 drive right from the ratchet.
2. Drain the Oil: Remove the drain plug with the 3/8" ratchet drive and catch the oil. Take a look at it, the volume, and what's collected on the magnet of the drain plug.
3. OPTIONAL- Flush: I used pump to flush the system with a little bit of oil as you don't need a full quart for the refill.
4. Fill with Oil: After thoroughly cleaning the drain plug, screw it back in. The PTU has a rubber gasket on the plug, but I used some teflon tape for the RTU as I didn't have any sealing compound. Make sure to keep the teflon off the magnet and out of the system as much as possible. I don't know the torque specs of this drain plug, but it should be 1/4-1/2 turn over snug. Don't crank it down as it's a nightmare if stripped.
Fill both until the oil starts to come out (fill to spill) as there is no dipstick. It took ~2/3 of a quart to fill each unit.
5. Install Fill Plug: Same as the drain plug, I added some teflon tape (only at the top) to make a better seal, but you can use a sealing compound as well.
Done! should only take about 30 min once the truck is jacked up.
PTU Pictures:
Drain plug had a healthy amount of build up (smudged with my thumb to show the depth), metallic particles in the oil (the "swirls" in the 2nd photo), and a considerably lower quantity than what I added back. This concerned me the most as it's the one that gets the hottest and powers the primary wheels. I'm glad I changed this and wish I had done it closer to 5k miles.
RDU Pictures:
Drain plug had a good amount of build up and the oil had a metallic color from fine particles (hard to capture without a video). Also saw some sludge at the bottom of the oil bucket. Fluid volume seemed to match what I added.
Thanks for reading!
There are a number of posts on here about the poor PTU/RDU fluids & wear from the factory and I wanted to add some fuel to the flame. I changed mine at ~13,000 miles and it was not in good shape (see pictures below). The PTU definitely seemed underfilled, had metallic debris, and a ton of sludge on the magnetic drain plug. The process was pretty simple, and definitely something you should do as part of your break-in fluid changes or with your first oil change (ideally before 5k miles).
You can also see some examples of higher mileage Mavericks that are already hitting transmission trouble. Daniel Deliverz has a great YouTube channel on the Mav (check it out here)
Simple explanation: a PTU (Power Transfer Unit) and RDU (Rear Drive Unit) are what transfer the engine & axial rotation that runs along the car, out sideways to power both wheels. Only the AWD version will have an RDU as they power all 4 wheels.
The Problem: In the Mav, the PTU is in a spot that sees a lot of heat from the engine/exhaust (causing oil to break down faster) and a lot of owners are reporting their trucks are coming from the factory with lower levers of oil. Both PTU & RDU systems are also always spinning, even if they aren't being powered. Meaning, they constantly need oil to stay lubricated, no matter if you're only running the front wheels, just doing normal driving, or idling (I think) . Plus, I saw a good amount of fine metallic debris/sludge that will create increased wear over time since there really isn't a filter in either unit (just a magnet). This is even more critical if you plan on towing or doing lots of "truck" stuff.
If you want your truck to last, change these oils ASAP!
How-to: There is already a great YouTube video on this by Dad's Garage that covers all the steps. This 1 is for the PTU and this 1 for the RDU. I don't have a lift, but was still able to do it with a jack & jack stands. Main difference is keeping the truck more-or-less level; so try not to jack it up too high. Also, make sure to pick-up an oil pump (something like this) as it will be near impossible to get the new oil in without it. I used OEM Motorcraft 75W Disconnect Rear Drive Unit Fluid (XY75WQL) for the RDU and Red Line 50104 75W85 GL-5 (Amazon) for the PTU. A lot of people recommend sticking with OEM for both, but I've had a lot of success in high heat applications using Red Line oil on my 2-stroke. Ultimately it's your call, but these fluids are OEM for good reason. You shouldn't need any additives as both motorcraft and red line already include the "friction modifiers" and such. Additionally, I wouldn't change to any other weight oil as these are very low volume systems that are engineered to perform a very specific way.
1. Remove the Fill Plugs: After you jack up the car, remove the FILL plug first. This prevents you being stranded if you can't get it off after draining. You'll need an 8 mm hex for the PTU plug and a pretty long ~10" extender. The RTU is the 3/8 drive right from the ratchet.
2. Drain the Oil: Remove the drain plug with the 3/8" ratchet drive and catch the oil. Take a look at it, the volume, and what's collected on the magnet of the drain plug.
3. OPTIONAL- Flush: I used pump to flush the system with a little bit of oil as you don't need a full quart for the refill.
4. Fill with Oil: After thoroughly cleaning the drain plug, screw it back in. The PTU has a rubber gasket on the plug, but I used some teflon tape for the RTU as I didn't have any sealing compound. Make sure to keep the teflon off the magnet and out of the system as much as possible. I don't know the torque specs of this drain plug, but it should be 1/4-1/2 turn over snug. Don't crank it down as it's a nightmare if stripped.
Fill both until the oil starts to come out (fill to spill) as there is no dipstick. It took ~2/3 of a quart to fill each unit.
5. Install Fill Plug: Same as the drain plug, I added some teflon tape (only at the top) to make a better seal, but you can use a sealing compound as well.
Done! should only take about 30 min once the truck is jacked up.
PTU Pictures:
Drain plug had a healthy amount of build up (smudged with my thumb to show the depth), metallic particles in the oil (the "swirls" in the 2nd photo), and a considerably lower quantity than what I added back. This concerned me the most as it's the one that gets the hottest and powers the primary wheels. I'm glad I changed this and wish I had done it closer to 5k miles.
RDU Pictures:
Drain plug had a good amount of build up and the oil had a metallic color from fine particles (hard to capture without a video). Also saw some sludge at the bottom of the oil bucket. Fluid volume seemed to match what I added.
Thanks for reading!
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