Lubricants for diff’s and xfer case
#1
07-20-2018, 01:18 PM
Lubricants for diff’s and xfer case
Hey Guys, I know this has been covered but looking back at some older threads, things seemed to change a little over time. My Truck recently went over 200k and I’m planning some services this weekend. On the front differential it looks like Ford recommended 75w90 up front for a long time but changed to 75w140 at some point. It’s suspected the change was more about stock and inventory that what is best for the diff. Any recommendations about which is better? If I buy an aftermarket product for the rear and it has the limited slip addative will it hurt to use it in the front also?
On the xfer case, Mercon is recommended but I found a video by a Ford Tech that says Mercon V was a bad choice. He, of course, said to use the MotorCraft Transfer Case Fluid (XL-12) any thoughts on that?
Thanks for any suggestions.
On the xfer case, Mercon is recommended but I found a video by a Ford Tech that says Mercon V was a bad choice. He, of course, said to use the MotorCraft Transfer Case Fluid (XL-12) any thoughts on that?
Thanks for any suggestions.
#2
07-20-2018, 02:09 PM
#3
07-20-2018, 03:40 PM
Ford came out with the transfer case oil XL-12 a few years back and stopped recommending use of Mercon V.
https://www.ford-trucks.com/forums/1...l#post15027674
It's a long thread, but if you wanna skip down to 16, I think that's where the XL-12 starts being talked about.
Stewart
#4
07-20-2018, 06:34 PM
Rear Differential: Valvoline Synthetic Synpower 75-140W and one bottle of Ford Limited Slip Fluid. Although Valvoline says that LS Fluid is not needed on the Valvoline bottle, the guy at Valvoline said to use one bottle of Ford LS Fluid. Don't use two.
Front Differential: Valvoline Synthetic Synpower 75-90W. A few months later I was near the end of my extended warranty and I had an unrelated concern. Since it was near the end of the warranty, the Ford house really had a look at everything and determined they needed to replace the axle seals (under warranty.) They had to drain the front differential and they replaced my fluid with 75-140W. This was in February 2014 and they said they only use 75-140 now.
Transfer Case: When I replaced the fluid in the transfer case the last time, I used Mobil 1 ATF Synthetic. There was a lot of chatter about Mercon-V and a lot of other fluids. I chose Mobil 1 because I could not find anything negative about using it in the transfer case and it seemed to be the fluid "For All Seasons.". Probably not the best reason in the world. I also use Valvoline fluids in the Subaru and Subaru cars are picky about what works and what doesn't.
As to Valvoline products, I have found them to be first class over the last 50+ years and their technical support line is competent. As an aside, I have used most major 15W-40 nonsynthetic oils in the Ford and have noticed no difference. I have not used synthetic oil since I tow in Texas and there has been some chatter about nonsynthetic being better in the heat for towing. Who knows.
Good luck Rusty with your fluid change. I hope it is cooler in Alabama than in Texas.
Front Differential: Valvoline Synthetic Synpower 75-90W. A few months later I was near the end of my extended warranty and I had an unrelated concern. Since it was near the end of the warranty, the Ford house really had a look at everything and determined they needed to replace the axle seals (under warranty.) They had to drain the front differential and they replaced my fluid with 75-140W. This was in February 2014 and they said they only use 75-140 now.
Transfer Case: When I replaced the fluid in the transfer case the last time, I used Mobil 1 ATF Synthetic. There was a lot of chatter about Mercon-V and a lot of other fluids. I chose Mobil 1 because I could not find anything negative about using it in the transfer case and it seemed to be the fluid "For All Seasons.". Probably not the best reason in the world. I also use Valvoline fluids in the Subaru and Subaru cars are picky about what works and what doesn't.
As to Valvoline products, I have found them to be first class over the last 50+ years and their technical support line is competent. As an aside, I have used most major 15W-40 nonsynthetic oils in the Ford and have noticed no difference. I have not used synthetic oil since I tow in Texas and there has been some chatter about nonsynthetic being better in the heat for towing. Who knows.
Good luck Rusty with your fluid change. I hope it is cooler in Alabama than in Texas.
#5
07-20-2018, 06:36 PM
#6
07-20-2018, 07:09 PM
#7
07-20-2018, 09:21 PM
Thanks fellas, I ended up with the Motorcraft XL-12 “Transfer Case Fluid” and a bottle of the XL-3 friction modifier from the dealership. The rest from O’Riley’s. Motorcaraft SP for the trans (yup, it’s that time again too), Gear oil options were limited, they had a couple of bottles of a lot of stuff but I read 3.5 quarts on the diffs and that narrowed it down to the store brand MasterPro GL-5 full synthetic. It has API GL-2 thru GL-5 service designations. I’m still not sure I’m going to use it without a little more more research (and you guys’s Opinion). Even that stuff was $12.99 a quart! They did have 75w90 for the for the front and 75w140 for the rear so I went with that. I can check AutoZone and Advanced to see what they have if you are suspicious of the MasterPro stuff, I can start working and then make a run in the wife’s car after they open in the morning. My motorcycle and the Jaguar project are both broke right now. Even with the filters I need on hand already, this is $340 in just lube and a tube of sealer for the diff covers, Dang!
I plan to start kinda early in the morning, I have a window A/C unit in a larger two car garage but it struggles in the afternoons, it hot here but not as bad as Texas! Lol. If I don’t have to open the big door much it will stay about 80° at most. I can take all day if I need to though, no plans except for this.
This is truck was over a hundred thousand miles when I got it and I didn’t get any history. I’ve kept up the oil and fuel filters, and did the trans on schedule since I’ve had it. The brake fluid has been flushed a couple of times and I flushed the hydra boost a few months ago just because the fluid was smelling bad. The coolant has been flushed once with chemicals and replaced a couple of times since because of water pump and later radiator replacement.
Now I plan to do the transfer case, diffs, trans, oil change, and fuel filters (again), am I missing anything on a 200k mile truck? Oh, I also plan a wash and vacum, I’ve kinda been ignoring her lately but it’s been running so good it’s just been crank and go.
I plan to start kinda early in the morning, I have a window A/C unit in a larger two car garage but it struggles in the afternoons, it hot here but not as bad as Texas! Lol. If I don’t have to open the big door much it will stay about 80° at most. I can take all day if I need to though, no plans except for this.
This is truck was over a hundred thousand miles when I got it and I didn’t get any history. I’ve kept up the oil and fuel filters, and did the trans on schedule since I’ve had it. The brake fluid has been flushed a couple of times and I flushed the hydra boost a few months ago just because the fluid was smelling bad. The coolant has been flushed once with chemicals and replaced a couple of times since because of water pump and later radiator replacement.
Now I plan to do the transfer case, diffs, trans, oil change, and fuel filters (again), am I missing anything on a 200k mile truck? Oh, I also plan a wash and vacum, I’ve kinda been ignoring her lately but it’s been running so good it’s just been crank and go.
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#8
07-20-2018, 09:24 PM
Nothing wrong with the master pro gear oil, just about all automotive fluids have to meet manufacturers specs before they can be sold to the public, I use the cheap Walmart brand stuff. Also I would hold off on adding that friction modifier the gear oil likely has some in it already, if you add to much it will cause your clutches to slip too much and the limited slip won't work as good, although it is probably worn out already, and they don't even work that good when brand new.
#9
07-20-2018, 09:34 PM
I think I read somewhere the GL-5 was with no friction modifier and they have a LS-5 with the limited slip additive, or that may have been another brand. I’ve done a lot of reading today and it’s past my bedtime and I’ve had a couple drinks...
i do remember seeing a couple of time in my reading that the LS isn’t very good on these trucks and a True Lock (or Track Lock?) was available thru Summit that was a decent price, bolt in upgrade. I do know I left a black mark leaving a stop sign a few weeks ago, I noticed it was a single mark, not two marks. I really haven’t done much work inside differentials though. I’m interested to see if there is any metal in the bottom of the housing.
i do remember seeing a couple of time in my reading that the LS isn’t very good on these trucks and a True Lock (or Track Lock?) was available thru Summit that was a decent price, bolt in upgrade. I do know I left a black mark leaving a stop sign a few weeks ago, I noticed it was a single mark, not two marks. I really haven’t done much work inside differentials though. I’m interested to see if there is any metal in the bottom of the housing.
Last edited by Rusty Axlerod; 07-20-2018 at 09:44 PM. Reason: add
#10
07-20-2018, 09:40 PM
I used the Valvoline 75w140 synpower in the rear and didn’t add any modifier and still have yet to hear or feel it clunk. Also used the Valvoline transfer case fluid. I have a hard time believing the hype about not using Mercon in the transfercase. There has to be more to the story about broken cases for example maybe they didn’t have fluid in it to begin with.
#11
07-20-2018, 09:49 PM
I think I read somewhere the GL-5 was with no friction modifier and they have a LS-5 with the limited slip additive, or that may have been another brand. I’ve done a lot of reading today and it’s past my bedtime and I’ve had a couple drinks...
i do remember seeing a couple of time in my reading that the LS isn’t very good on these trucks and a True Lock (or Track Lock?) was available thru Summit that was a decent price, bolt in upgrade. I do know I left a black mark leaving a stop sign a few weeks ago, I noticed it was a single mark, not two marks. I really haven’t done much work inside differentials though. I’m interested to see if there is any metal in the bottom of the housing.
i do remember seeing a couple of time in my reading that the LS isn’t very good on these trucks and a True Lock (or Track Lock?) was available thru Summit that was a decent price, bolt in upgrade. I do know I left a black mark leaving a stop sign a few weeks ago, I noticed it was a single mark, not two marks. I really haven’t done much work inside differentials though. I’m interested to see if there is any metal in the bottom of the housing.
#13
07-20-2018, 10:12 PM
Yea I have my doubts about the Mercon V making the transfer case blow up, there isn't much to a transfer case, just a chain, gears, and bearings, some people even run gear oil in it. Keep in mind Mercon and Mercon V are not the same you can run regular Mercon spec fluid in it or atf+4 which is what Chrysler recommends, the 03-14 Ram 2500 and 3500 use the same transfer case.
#14
07-20-2018, 11:05 PM
Logistics Pro
I did a little searching around and found a few horror stories about T-case failures and found some additional info. Evidently some early transfer cases failed because a particular bearing wasn't getting enough lubrication.
My 2005 F350 has the New Process NP273 T-case. The following site describes some of the problems that were evidently fixed in later models.....(don't know when they made the changes though)
https://www.midwesttrans.com/NP273.html
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