At 20k miles since my last transfer case fluid change in the 2011 and need to get the factory fill out of the 2018. Both are now rated for Mercon LV in the transfer case, so that may, potentially, simply some things. What I'm concerned about is the 2011, though. Historically this truck has demonstrated spline slip bump refractory to all interventions. This is the transfer case slip yoke splines as it is a one piece driveshaft. After trying all types of different greases and pastes including NLGI 2 with moly, moly paste and two different Ford/Motorcraft teflon/ptfe greases the most ever got was a few thousand miles (like 6k MAX usually just a couple hundred) before it returned. Eventually I hit the 100k service and drained the transfer case which undoubtedly came out silver/grey/black. No other mechanical symptoms so maybe its lube contamination from the greases but I doubt it (which is one reason I will be changing the 2018 early). Well anyways at 100k miles I drained it and refilled with Amsoil universal ATF- not the LV version. Sure enough, slip bump disappeared! Now I'm 20k miles down the road and still silky smooth off the line.
Given the above, I am due for my not exactly annual trans pan drain and fill. Great time to replace the transfer case, though for the most part I'm just curious how the fluid is looking. Interestingly it looks like Ford has canceled the XL-12 (aka Dex/Merc) spec and back spec'd Mercon LV for this transfer case. Not entirely a bad thing as the lower viscosity can only help in winter, which is 99% f my 4WD use, and shouldn't hurt mileage either. Modern synthetics, I have no real concern about wear issues or heat either - especially in a low demand application like a chain drive, part time transfer case. What I am trying to decide on is if it makes more sense to switch to LV at this point or stick with the tranditional Amsoil universal ATF? The main benefit of going LV is economy in that I could just buy two jugs of MaxLife ATF (not to start an arguement but that is my choice for ATF in this application) and not have to worry about any extra shopping.
Now the specs of all three (Maxlife, Mercon LV, Amsoil ATL) are extremely similar and Amsoil ATF is, of course slightly more viscous. What I am wondering is, will that make a HOOT of difference to my transfer case slip yoke splines? As described above it would certainly appear that the primary factor in lubrication is the transfer case fluid. Thick = better? Thinner = better? Or too close to matter and base oils, additives, etc make more difference? The viscosity range in cst at 100C for LV is 5.9 for Maxlife, 6.0 Motorcraft and 6.3 Amsoil ATL with the ATF running 7.5. Semi interestingly, despite the thinner fluid at operating temp the brookfield is lower for the Amsoil ATL making me wonder if its a higher quality fluid. While the price difference as a percentage is significant in reality its only a few dollars more so I don't mind running the premium option if there is actually a benefit.
MaxLife Datasheet
Amsoil ATL and ATF datasheet
Mercon LV Datasheet
Given the above, I am due for my not exactly annual trans pan drain and fill. Great time to replace the transfer case, though for the most part I'm just curious how the fluid is looking. Interestingly it looks like Ford has canceled the XL-12 (aka Dex/Merc) spec and back spec'd Mercon LV for this transfer case. Not entirely a bad thing as the lower viscosity can only help in winter, which is 99% f my 4WD use, and shouldn't hurt mileage either. Modern synthetics, I have no real concern about wear issues or heat either - especially in a low demand application like a chain drive, part time transfer case. What I am trying to decide on is if it makes more sense to switch to LV at this point or stick with the tranditional Amsoil universal ATF? The main benefit of going LV is economy in that I could just buy two jugs of MaxLife ATF (not to start an arguement but that is my choice for ATF in this application) and not have to worry about any extra shopping.
Now the specs of all three (Maxlife, Mercon LV, Amsoil ATL) are extremely similar and Amsoil ATF is, of course slightly more viscous. What I am wondering is, will that make a HOOT of difference to my transfer case slip yoke splines? As described above it would certainly appear that the primary factor in lubrication is the transfer case fluid. Thick = better? Thinner = better? Or too close to matter and base oils, additives, etc make more difference? The viscosity range in cst at 100C for LV is 5.9 for Maxlife, 6.0 Motorcraft and 6.3 Amsoil ATL with the ATF running 7.5. Semi interestingly, despite the thinner fluid at operating temp the brookfield is lower for the Amsoil ATL making me wonder if its a higher quality fluid. While the price difference as a percentage is significant in reality its only a few dollars more so I don't mind running the premium option if there is actually a benefit.
MaxLife Datasheet
Amsoil ATL and ATF datasheet
Mercon LV Datasheet