Originally posted by glock-coma
Changed RDU fluid today
#1
04-14-2013, 08:40 PM
Just thought I would post some pics
Here are some DIY 2"x12" car ramps I made.
Found these over @ evolutionm forum
http://forums.evolutionm.net/evo-x-g...bout-40-a.html (http://forums.evolutionm.net/evo-x-g...bout-40-a.html)
(http://images.tapatalk-cdn.com/15/12/04/15247f96ae632b547180a06711f6ddd5.jpg)
I used a Hydro-Turf oil extractor and a quart fluid pump both found on amazon.
http://www.amazon.com/Hydro-Turf-Oil...sim_sbs_auto_1 (http://www.amazon.com/Hydro-Turf-Oil...sim_sbs_auto_1)
(http://images.tapatalk-cdn.com/15/12/04/e3b533df28eb2b2d5cffc8b847ae2d4e.jpg)
Pic of RDU fill plug....I used a 3/8 drive ratchet to remove it. The hole is pretty shallow, so the ratchet will not go completely in. Anyone know why that exhaust hangar is there?
There is not a bracket on the pipe below it
(http://images.tapatalk-cdn.com/15/12/04/0bb8561846c9aab2be1da9df6f5dc581.jpg)
Drain plug before cleaning, and after. Some metal filings, but nothing to worry about
(http://images.tapatalk-cdn.com/15/12/04/414d721c2f39ebd3ca684204400b6e02.jpg)
(http://images.tapatalk-cdn.com/15/12/04/8a926ac4c7dcbebd86d51997e657dd1f.jpg)
I couldn't completely warm up the fluid for easier extraction, I didn't want to deal with a hot exhaust while under the car. It was moving very slowly through the tube.
(http://images.tapatalk-cdn.com/15/12/04/4f76d3b3f810dc7c4e92d77fe067cb31.jpg)
I got out as much as I could, about 32 ounces by weight.
The fluid was pretty nasty. It was the consistency of syrup, maybe a little thicker
(http://images.tapatalk-cdn.com/15/12/04/a0529e0b50122927870e6a4e27b179ad.jpg)
Here is a side by side of old fomoco "lifetime" fluid and new redline 75-w90
(http://images.tapatalk-cdn.com/15/12/04/0c0638f3a66e9abd60fc32ea9aa6f92e.jpg)
Wasn't that hard of a job, the pump just took awhile because of the thickness of the fluid.
While I was waiting, I also changed the spark plugs to the new updated part number CYFS-12Y-3. Probably going to do the PTU fluid next week.
Last edited by glock-coma; 04-14-2013, 10:49 PM.
12/4/2015: Thanks for the re-linked images, glock! Much appreciated :thumb:
Lovely how-to. How'd that extractor pump work? I think I'll pick one up.
So, to be clear...
The RDU has a fill plug only. No drain. Thats where a pump or suction device comes in.
How about the PTU? Aux cooler (Perf. package) equipped SHOs have a fill AND drain on the PTU, correct? Both accessable by removing one or both primary cats. But those without the aux cooler do NOT have a drain, thus require a suction device as well. Is that correct?
I purchased a cheap but pretty descent suction gun along with an 3/8 hose extender,can probably do the CAC or maybe other applications as soon it gets warmer out. http://www.amazon.com/gp/product/B000MD4YNY/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 (http://www.amazon.com/gp/product/B000MD4YNY/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
I just popped the cover when I changed mine. Just have to buy some RTV and you can wipe out more old fluid with a towel.
ALso meant to add awhile back when I changed my PTU the fluid looked ok but it was only at about 5K miles. People were wondering what relatively new fluid looked like since people were seeing bad fluid at 20k. I wanted to change mine before it had a chance to turn bad.
And I'm not sure but I don't think it would do any good to drive the car to try and heat up the Rear diff because I think the clutch pack that activates the rear is in the PTU and only comes on when needed. I don't think the driveshaft spins until needed.
I would think the driveshaft would spin as long as the engine is running/ trans is not in neutral or park to avoid the startup inertia, no? Should still take longer to warm up the RDU though.
Quote from: SHOdded on February 22, 2015, 03:43:36 PM
I would think the driveshaft would spin as long as the engine is running/ trans is not in neutral or park to avoid the startup inertia, no? Should still take longer to warm up the RDU though.
Now that I think of it I think you are right, the clutch packs in the PTU just engage to link the 2 when needed.
That not correct. The clutch is a part of the RDU. The PTU is always engaged and the drive shaft is alway spinning. The electronically controlled clutch engaged RDU when needed. There is no clutches in the PTU what so ever.
electronic clutch circled in red.
(http://i1125.photobucket.com/albums/l583/crash712us/3547724924_c52e617260_zps8cb95ddf.jpg) (http://s1125.photobucket.com/user/crash712us/media/3547724924_c52e617260_zps8cb95ddf.jpg.html)
Sent from my iPhone using Tapatalk
Pictures are not showing up...
No picture !!!!
How did y'all stick that ratchet in there? My standard 3/8" drive ratchet won't fit because of the exhaust hanger and that IRS cradle. I'd have to get a really slim ratchet in there?
Quote from: metroplex on September 03, 2016, 03:34:44 PM
How did y'all stick that ratchet in there? My standard 3/8" drive ratchet won't fit because of the exhaust hanger and that IRS cradle. I'd have to get a really slim ratchet in there?
You need to go from the top and fish the ratchet down and into the plug. It's tight, but it will fit.
I used several 3/8" extensions through the passenger side wheel well maybe a crows foot wrench with a 3/8" adapter would work
I tried going from the top, it almost fit. I have a Gear Wrench pass-thru wrench set that I should have thought to try, it's like 1/4" thinner than my normal ratchet.
Is the RDU just an open differential? Is there any merit in using some Lubegard Gear Fluid additive (which is supposed to help reduce temperature and reduce friction) to help out the RDU and the PTU given that we don't have a lot of oil to work with?
The RDU uses a electronically controlled clutch so I wouldn't use anything that reduced friction.
sent from my speak n' spell using tin cans and string
So the electronic clutch mechanism is in contact with the RdU gear oil?
It doesn't seem to be actually part of the differential fluid system: http://www.shoforum.com/index.php?threads/how-does-the-awd-work.119781/ (http://www.shoforum.com/index.php?threads/how-does-the-awd-work.119781/)
Quote from: metroplex on September 03, 2016, 09:09:49 PM
So the electronic clutch mechanism is in contact with the RdU gear oil?
It doesn't seem to be actually part of the differential fluid system: http://www.shoforum.com/index.php?threads/how-does-the-awd-work.119781/ (http://www.shoforum.com/index.php?threads/how-does-the-awd-work.119781/)
Here some info on the AWD for your reading pleasure. Z Police-only Cooling
The police version of AWD has three unique features to improve durability during severe use. First, the Power Transfer Unit on the AWD system uses a police-only auxiliary cooler. The retail AWD unit is air cooled, i.e., the aluminum housing dissipates heat to the surrounding air. When the vehicle is stationary, the amount of cooling is obviously less than when the vehicle is moving.
On the police AWD unit, the front housing of the Power Transfer Unit has a special water jacket cast into the assembly. The integral PTU auxiliary cooler is part of the water cooling system. That means the cooling remains "active" since the cooling water is constantly circulated, whether the police vehicle is moving or stationary.
The PTU cooler is plumbed into the bottom of the radiator, where the water is cooler than at the top of the radiator.
Second, the Power Transfer Unit uses an internal temperature sensor, not found on the retail unit. A module keeps track of oil temperature in the PTU and the amount of time spent at that temperature. An electric clutch pack engages and disengages as torque is transferred to the rear wheels.
Both the PI Sedan and PI Utility default to FWD under normal conditions. As the front wheels slip, torque is selectively diverted to the rear wheels. A time versus temp logarithm activates an Oil Minder light in the driver message center if and when it is time to change the PTU fluid. The special synthetic oil may last 100K miles in normal police use.
Third, the Rear Differential Unit on the police version uses a fluid-filled clutch pack, while the retail version uses dry clutches. The fluid-filled RDU can withstand more severe duty.
The cooling ability of the police-only auxiliary radiator-water jacket combination was tested in 110 deg. F weather. Hard driving—where power is constantly shifting from front to rear, back and forth—can take many different forms.
Think aggressive driving during a city pursuit: hard throttle for a city block, 90-degree turn, hard throttle, where torque definitely shifts from front to rear. Also think getting unstuck in desert sand. Even though the vehicle and wheel speeds are not high, torque is constantly shifting between the front and rear spinning wheels.
Under the worst conditions of high-torque, clutch engagement and disengagement, the synthetic oil reached temperatures around 195 deg F. The special lube is rated for temps just over 500 deg F. The air-to-water cooler works. http://www.hendonpub.com/resources/article_archive/results/details?id=5091 (http://www.hendonpub.com/resources/article_archive/results/details?id=5091)
FWIW the Gear Wrench pass-thru ratchet worked perfectly, it was slim enough to slip between the cradle and fill plug either from the bottom or from the top!
Called my dealer the other day to get a quote on having the PTU and RDU fluid swapped out and they said they wouldn't do it. Claimed there is no drain plugs to do so. Guess I'll do it myself one weekend when I have time.
I suggest finding out where the Police service their Interceptors and try them. Other option is a Lincoln dealer. My wife works at a Lincoln dealer and they don't see anything odd with the request.
Quote from: ZSHO on February 22, 2015, 07:45:32 AM
I purchased a cheap but pretty descent suction gun along with an 3/8 hose extender,can probably do the CAC or maybe other applications as soon it gets warmer out. http://www.amazon.com/gp/product/B000MD4YNY/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 (http://www.amazon.com/gp/product/B000MD4YNY/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
How did that Amazon suction gun work out, for you?
Sent from my SAMSUNG-SM-G930A using Tapatalk
I just used suction pumps from Harbor Freight and Advance Auto
First and foremost, Thanks for the How-to Glock. I was able to get the time today to complete this project. Car has about 42k+ miles. I was able to extract about 50oz. of fluid by jacking the front of the car of higher then the back end. Fluid still looked really good for the amount of miles.
That RDU looks to be in fine shape!
Yes it does, especially how I drive, lol.
Sent from my SM-G935T using Tapatalk
Has anyone with a 13+ PP pulled this off without a lift? Give us a drain plug, then cover it up...brilliant
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Found the thread in how-to's. My bad
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Quote from: AJP turbo on February 22, 2015, 03:06:39 PM
I just popped the cover when I changed mine. Just have to buy some RTV and you can wipe out more old fluid with a towel.
no issues with this? I want to have mine replaced soon, and the ford workshop manual says if the rdu cover is stamped steel (basically non ecoboost rdu), you can pop it off to drain and silicone it back up. it states that if the cover is aluminum (ecoboost) replace the rdu, it's not serviceable (even though there is a plug in the cover...). I would rather have the mechanic remove the cover and get all the crappy 80w90 out and replace with my 75w90 amsoil.
In my honest opinion, don't bother changing the rear differential gear oil. On my older RWD cars, I could punish the heck out of them after 100k miles using non-synth 80W-90 and the gear oil looked fine with minimal metal shavings. On the D3/D4 AWD vehicles, the rear differential is a much smaller unit and you're not sending all the power to the back. Plus, these are essentially open carriers as well so there are no clutch/steel packs or torsen gears spinning around. I wouldn't bother, but if you absolutely want to change it, a suction pump would make it easier without having to pull the cover or mess with RTV/sealing.
Quote from: cseverens on January 31, 2018, 03:36:26 PM
Quote from: AJP turbo on February 22, 2015, 03:06:39 PM
I just popped the cover when I changed mine. Just have to buy some RTV and you can wipe out more old fluid with a towel.
no issues with this? I want to have mine replaced soon, and the ford workshop manual says if the rdu cover is stamped steel (basically non ecoboost rdu), you can pop it off to drain and silicone it back up. it states that if the cover is aluminum (ecoboost) replace the rdu, it's not serviceable (even though there is a plug in the cover...). I would rather have the mechanic remove the cover and get all the crappy 80w90 out and replace with my 75w90 amsoil.
DOn't overthink it...No issues....It's just like any other rear end and there was shavings on the magnet ...I changed my fluid with less than 2k on the car to put real synthetic gear lube in. It's absolutely serviceable...I don't remember if the clutches in the electronic portion of the RDU are exposed to fluid or not but for me it's worth the 15$ qt of amsoil and a tube of RTV to have the best stuff in there.
Quote from: AJP turbo on January 31, 2018, 04:34:52 PM
Quote from: cseverens on January 31, 2018, 03:36:26 PM
Quote from: AJP turbo on February 22, 2015, 03:06:39 PM
I just popped the cover when I changed mine. Just have to buy some RTV and you can wipe out more old fluid with a towel.
no issues with this? I want to have mine replaced soon, and the ford workshop manual says if the rdu cover is stamped steel (basically non ecoboost rdu), you can pop it off to drain and silicone it back up. it states that if the cover is aluminum (ecoboost) replace the rdu, it's not serviceable (even though there is a plug in the cover...). I would rather have the mechanic remove the cover and get all the crappy 80w90 out and replace with my 75w90 amsoil.
DOn't overthink it...No issues....It's just like any other rear end and there was shavings on the magnet ...I changed my fluid with less than 2k on the car to put real synthetic gear lube in. It's absolutely serviceable...I don't remember if the clutches in the electronic portion of the RDU are exposed to fluid or not but for me it's worth the 15$ qt of amsoil and a tube of RTV to have the best stuff in there.
The rear differential is separate from the viscous coupling unit. I guess use whatever makes you think it is running better, but my recommendation is to save your money and time and not bother with the rear differential on the D3/D4 AWD vehicles.
I guess if you believe it's "lifetime fluid" like ford suggests then don't change it..but they said the same about the ptu...so for the little effort and time that it takes id put the best in there
Absolutely NOT the way to think about this. Sure the RDU fluid lasts longer, but fluid does wear out. Considering that the newer MYs can send nearly 100% power (be it momentary) to the back wheels, easy to justify why.
Now, does the PTU need more maintenance. Definitely. It does most of the heavy lifting, being in a FWD-biased system. So you do not have to service the RDU as often as the PTU. But preventive maintenance is good practice, period. RDUs have been known to vent fluid, and grind and whine their way to death. Changing the fluid is easy peasy compared to the PTU. Just do it.
The RDU only takes 2.4 pints (1.15L) which is roughly a Quart of oil for a peace of mind! Z
I didn't know Ford claimed the rear diff fluid was lifetime, but my experience has been that the fluid in the back lasts a long time, like 100k+ miles. And this is also from personal experience with RWD cars that send 100% of the power to the back all the time 24/7. I know the AWD meter on the instrument panel shows a lot of power going to the back wheels during takeoff (even on my 2014 SHO) but it's not wearing down the fluid anytime soon. The PTU fluid should be changed every 20k miles, even with the factory "cooler".
Again if you feel the need to spend the money on Amsoil for the rear diff to make yourself feel better, it's not going to hurt but my recommendation is to not bother. Maybe change it at high mileage (100k miles or so) if you feel the need.
This forum officially recommends: Change the RDU fluid at every other PTU fluid change. Motorcraft will probably be fine, but if you can step up to a top notch product like Amsoil or Redline, why not?
Just like with engine oil, the change interval is just as if not more important. The "lower" the quality of fluid you use, the more often you should be changing it.
Normal vs Severe conditions! Z
Ford goes even further and for some models for normal driving conditions does not recommend changing synthetic gear oil in rear axles and power take off (PTO) units (transfer cases), saying they are lubricated for life. However, we found plenty of disagreement among technical experts.
http://www.testingautos.com/car_care/how-often-to-change-gear-oil.html (http://www.testingautos.com/car_care/how-often-to-change-gear-oil.html)
Well, one could have the "good enough" attitude about fluids but...
The Quantum Blue PTU/RDU made an immediate difference in the power going to the rear of the 15
The car felt different, the chassis felt looser, kind of felt like the rear of the car "decoupled" from the front.
The rears spun immediately with part throttle from a stop and that was from the second I left the dealership. Rear roasty roast in first became easy to invoke with nothing but a blip of the throttle and the car became a handful in the rain as I could get the car completely sideways. I actually had to have Brad adjust my throttle settings to tame it a bit because I came very close to completely losing it one day on my way to work.
Hows that possible? Less friction and heat equals more power to the ground.
Brian claimed a complete fluid change was good for 15-35 HP at the wheels depending on platform and I tend to believe that based on my experience.
I went with Amsoil all the way around this time so I can see if the effect is the same (Amsoil is about half the price of QB fluids) but if not I will drain out the Amsoil and replace with QB.
Personally I'd rather spend money on high quality fluids that protect my investment instead bolt ons that really don't do squat.
Quote from: metroplex on January 31, 2018, 05:42:36 PM
I didn't know Ford claimed the rear diff fluid was lifetime, but my experience has been that the fluid in the back lasts a long time, like 100k+ miles. Maybe change it at high mileage (100k miles or so) if you feel the need.
I have 91k on her now. I bought it less than 2 years ago with 42k miles on it. I don't believe in lifetime fluids.
Generally the rule to follow with buying a used vehicle is to assume no maintenance has been done. And at the very least, R&R all the fluids.
Quote from: FoMoCoSHO on January 31, 2018, 10:24:19 PM
I went with Amsoil all the way around this time so I can see if the effect is the same (Amsoil is about half the price of QB fluids) but if not I will drain out the Amsoil and replace with QB.
Keep us posted, I am close to oil change time and while she is up in the air showing her naughty bits I might as well give her a thorough vaccination panel... I did PTU at last oil change, RDU now, and then synch them up in next series.
i dropped her off at the shop this morning. we'll see what happens.
Good luck, excited to hear about the results :D
it'll get a work out right away. tomorrow I have to go to RI, so about 150 miles round trip. then I have work in nh this weekend, so about another 520 miles roundtrip there, and then next Friday I hit the road for Disney. roundtrip is about 2800 miles.
Will love it :)
the shop wouldn't do it. they said ford told them to use a special pump to suck it out and refill it, which they don't have. they said the rear crossmember gets in the way of removing the rear cover. guess I'm s-o-l for now.
Quote from: cseverens on February 07, 2018, 11:35:49 AM
the shop wouldn't do it. they said ford told them to use a special pump to suck it out and refill it, which they don't have. they said the rear crossmember gets in the way of removing the rear cover. guess I'm s-o-l for now.
That is such BS!!! There is an access hol e in the rear subframe to access tge drain/fill hole on th e rear diff cover. Any kinda suction pump will pull the fluid out. Filling it, is a non issue. Hand pump you can reill. I went and bought another cover and made a drain plug to make fluid changes easier.
so, if anyone somewhat nearby that has done this wants to make some extra money, hit me up. I was hoping to have it done before the florida trip, but that is unlikely now.
Quote from: bamsho on February 07, 2018, 11:47:06 AM
Quote from: cseverens on February 07, 2018, 11:35:49 AM
the shop wouldn't do it. they said ford told them to use a special pump to suck it out and refill it, which they don't have. they said the rear crossmember gets in the way of removing the rear cover. guess I'm s-o-l for now.
That is such BS!!! There is an access hol e in the rear subframe to access tge drain/fill hole on th e rear diff cover. Any kinda suction pump will pull the fluid out. Filling it, is a non issue. Hand pump you can reill. I went and bought another cover and made a drain plug to make fluid changes easier.
Yes it is...Do yourself a favor....Never ever go to that shop for anything....If you can change your own oil then you can do this job...The subframe doesn't get in the way of anything!.WOW just WOW. It's mind blowing that a real shop would say this...No vcuum pump needed! A small tube of RTV and gear oil and some sockets and a ratchet......Don't ever go to that shop...They are either stupid or crooked....In either case there is never a need to go there....That's what's needed to put them out of business.
So what is the forum recommended lube for the rear diff and how much. My rear whole diff end to end was replaced at 44,000 miles I have 63,500 now and want to replace with some good stuff then I will leave alone for awhile. Doing the PTU fluid this week with Amsoil severe duty, it too was replaced at 44,000. I will replace the PTU fluid every 20 or 30,000 miles...
Redline Lightweight Shockproof or SuperLightWeight Shockproof should work well for the RDU. Also Amsoil Severe Gear. Quantity is nearly 36 oz, IIRC. 2.4 pints.
You can actually clean out the RDU if you choose to do so since it is easy to remove the cover. Then seal the cover back onto the RDU, allow to cure, fill with new fluid via fill hole.
bamsho has a HOWTO on installing a drain plug for the RDU if you care to do that.
I put royal purple in last fluid change. I'm currently in the process of changing over to amsoil severe gear for PTU and RDU
Let us know how it works out!
A few things that might help you guys. 1) They make square drives that fit inside a ratchet wrench that buys you some room on the plug, and 2) as any NASCAR fan should know-take a sawzall and lop off that extra exhaust hanger that serves no purpose on our car (SHO) and hit it with some black paint.