Ralph Greene Posted September 25, 2008 Share Posted September 25, 2008 My wife's 2005 Mercury Montego is going into dealership tomorrow for it's 30,000 mile service. I can't tell from the owners manual or the maintenance manual if the trans fluid is scheduled to be changed. No where in these manuals does it describe the Aisin 6 speed auto with a trans number descriptiom. If I had that Ford trans number, I could figure out if it is scheduled to be changed. I found the dip stick. I assume, if it is scheduled to be changed, it takes the new Premium Auto trans fluid for 6 speed automatic transmissions. But not so sure about that even for this Toyota product. All info appreciated. Thanks Quote Link to comment Share on other sites More sharing options...
theoldwizard Posted September 25, 2008 Share Posted September 25, 2008 Looking at the service requirements for 2007 (which should be pretty close), no transmissions on any ford/Mercury cars require transmission oil change at 30K. All it says is "inspect". 4F27E (not Aisin 6 speed; hint 4F is a 4 speed Front wheel drive transmission) requires change at 60K. All transmissions used in Ford or Mercury product have used Mercon V oil for several years now and it is backward compatible. The Motorcraft version is a blend of natural and synthetic oil, although some aftermarket Mercon V are 100% synthetic. Quote Link to comment Share on other sites More sharing options...
Ralph Greene Posted September 26, 2008 Author Share Posted September 26, 2008 Looking at the service requirements for 2007 (which should be pretty close), no transmissions on any ford/Mercury cars require transmission oil change at 30K. All it says is "inspect". 4F27E (not Aisin 6 speed; hint 4F is a 4 speed Front wheel drive transmission) requires change at 60K. All transmissions used in Ford or Mercury product have used Mercon V oil for several years now and it is backward compatible. The Motorcraft version is a blend of natural and synthetic oil, although some aftermarket Mercon V are 100% synthetic. Thanks for info. However....the owners manual says Mercon V is not to be used in 6 speed auto trans, that the newer Premium Auto trans fluid is to be used that was developed when the 6 speed auto's were developed. However, my Aisin 6 speed auto not one of those transmissions. I suspect you are correct about not being serviced at 30,000. I guess I will have to trust the tech to know what he is doing. Thanks Quote Link to comment Share on other sites More sharing options...
Ralph Greene Posted September 26, 2008 Author Share Posted September 26, 2008 (edited) From searches....I have discovered my wife's 2005 Montego with 6 speed auto has the Aisin AWF21 transmission. It has a very short dip stick located under and to the right of the engine....where you either get hot or dirty to check it. The owners manual say all 6 speed transmissions take the new Premium auto trans fluid. Using a Mercon fluid will void warranty. The first reference to change interval in both the owners manual or the maintenance manual is at 150,000 miles. This seems excessive to me....even with new super dooper trans fluid. Opinions... Edited September 26, 2008 by Ralph Greene Quote Link to comment Share on other sites More sharing options...
lfeg Posted September 26, 2008 Share Posted September 26, 2008 Unless you are using the car in severe stop and go driving or towing at max rating in 100+ degree weather, go with the factory interval. We use the plain old Mercon / DexronIII fluid in applications much more severe than you would ever see in a car or pickup, and as long as we keep peak temperatures below 260° a fluid life of 5000 hours or more is not unusual. Synthetic blends and full synthetics will last even longer. Quote Link to comment Share on other sites More sharing options...
theoldwizard Posted September 27, 2008 Share Posted September 27, 2008 Thanks for info. However....the owners manual says Mercon V is not to be used in 6 speed auto trans, that the newer Premium Auto trans fluid is to be used that was developed when the 6 speed auto's were developed. However, my Aisin 6 speed auto not one of those transmissions. I suspect you are correct about not being serviced at 30,000. I guess I will have to trust the tech to know what he is doing. Thanks Wow, talk about confusing ! First, the AWF21 (Asisn) 6 speed automatic does require the Premium Automatic Transmission Fluid ! This transmission was only used in V6 Fusion/Milan and some(?) MKZ (not certain if MKZ with 3.5L got mated with AWF21). Second, this is not the only 6 speed front wheel drive transmission in Ford/Mercury/Lincoln products and has been phased out as of 2009MY ! There are 2 other 6 speed front wheel drive transmission, 6F50 and 6F35. The 6F35 is new for 2009MY and is mated behind 4 cylinder engines. These transmission use Mercon V. Older Fusion/Milan with 4 cylinders and 5 speed automatics (FNR5) also uses a unique fluid. If you have a CVT there is unique fluid for it ! Quote Link to comment Share on other sites More sharing options...
Ralph Greene Posted September 27, 2008 Author Share Posted September 27, 2008 Wow, talk about confusing ! First, the AWF21 (Asisn) 6 speed automatic does require the Premium Automatic Transmission Fluid ! This transmission was only used in V6 Fusion/Milan and some(?) MKZ (not certain if MKZ with 3.5L got mated with AWF21). Second, this is not the only 6 speed front wheel drive transmission in Ford/Mercury/Lincoln products and has been phased out as of 2009MY ! There are 2 other 6 speed front wheel drive transmission, 6F50 and 6F35. The 6F35 is new for 2009MY and is mated behind 4 cylinder engines. These transmission use Mercon V. Older Fusion/Milan with 4 cylinders and 5 speed automatics (FNR5) also uses a unique fluid. If you have a CVT there is unique fluid for it ! Yes....it is confusing. Fortunately for me...my Lincoln mercury dealership is a fine place to do business (better than my Ford dealership with their sloppy work) and the tech that serviced the car is an honest competent tech and said the fluid was fine at 30,000 miles, no need to change it. It is a serviceable transmission, so we will monitor the fluid and if we still own the car at 60,000, which we probably will, I'll consider changing it out then. We really like this car because it's so large and confortable, I can haul 2 bikes in it, and it gets 29-30 MPG on trips and 22-23 around town. When I change the fluid it takes, according to manual, the newer Premium fluid. I understand it's a lighter weight fluid than the Mercon V, probably full synthetic I would guess. My owners manual calls for service and trans filter replacement at 150,000 miles. And yes....if it was the AWD CVT, that takes a special CVT chain type fluid. The techs have to be very alert these days servicing these cars. Thanks for contributions. Quote Link to comment Share on other sites More sharing options...
akirby Posted September 27, 2008 Share Posted September 27, 2008 We've had this discussion with 2 different Ford transmission engineers. One says to change it every 30K regardless of what the manual says because any duty is severe duty. The other says 100k-150k is fine. I think 30k or 60k is cheap insurance. I wouldn't wait longer than 60k. Quote Link to comment Share on other sites More sharing options...
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