wwest

With a leak pedal travel would get progressively worse. It's possible a brake piston is consistently retracting more than normal. A warped rear rotor, or maladjusted drum brake, might cause that and still not be very noticeable.

Here in WA it is illegal to use studded tires except during the designated period, wintertime period. Tire chains are a quite viable temporary solution when traveling in areas where traction devices are required. On some rare occassions around here, WA/OR/ID/MT/WY, tire chains might be required by the man in the square brimmed hat in order to proceed even with 4Wd/4X4 and winter tires w/studs.

Yes, and since you have bought that marketing hype I have a bridge in Brooklyn for sale and maybe some land in Florida. I lived in central MT for many years, still oftentimes travel there, sometimes even in the wintertime. Back in those days walnut shells were often embedded in the tire rubber in order to increase traction. Those were maybe good for one season, but did the job extremely well. If, as you say, winter specialty tires are softer, or remain more resilient in the COLD, how is it that have the same tread wear mileage rating as my summer only tires?? Have you ever seen a traction test of one vs the other on packed snow or ice...? I thought not.

Wow, getting around that tightly packed V8 in the SC to do all that would not only tire me out but result in lots of knuckle bandaids. SC400 Struts....I hope you put in new "strut" insulator/bellows/boots at the same time. That "clunk"/thunk sound you were hearing driving over slight bumps at fairly low speed was not the struts but the top of the coil spring striking the strut mounting plate. I installed 5/8" automotive water hose over the first 360 degrees of the top of the coil springs so that would not repeat.

Us old fuddy-duttys are well aware that studs only on the drive wheels of RWD vehicle do not represent a problem. Whereas since most "crossovers" are of FWD origin then using studs ONLY on the drive wheels represents a very serious risk. That may well be what "dad" was trying to convey. For FWD or F/awd vehicles, traction enhancing devices, chains, studs, wintertime specialty tires, whatever, MUST be used on all four corners. Additionally. Tire studs actually reduce the tire's traction on a dry or wet roadbed, so you might find ABS, TC or VSC activating more often, much more often, in those conditions than would a simple summer only, or even a wintertime treaded tire. It is MMHO that summer only use tires are the best way to go all year around. but then be quick to install tire chains (on the rear first and then the fronts to if needed or if FWD). Wintertime specialty tires work fine, excellently, if the tread can "bite" into the surface layer, mud, loose freshly fallen snow, for instance. Once the snow is packed down or the surface is mostly iced over studs are chains will be the only answer. So, summer tires come out ahead overall, quieter and more comfortably riding, and more CSA contact area on solid surfaces.

I wonder if the Mazda CX-7's water cooled PTO will bolt up to the Ford transaxle...?? Since the Ford Escape, Mercury Mariner and Mazda Tribute share almost all aspects.... What's the word on the Mazda Tribute PTO...same problems..??

No. My thinking was more along the lines, "lightweight" lines, of the Toyota Venza or the Mazda CX-7.

It's been quite a few years since I did any computer field service work(***) in MN but back then in the wintertime one of these new F/awd making use of TC would have been quite seriously challenged vs almost any other area of the US, excepting MT and Alaska, of course. For a number of years I had to travel between Seattle and Boston on a fairly regular basis. I quickly learned that if I didn't wish to spent cold winter nights in motels in close proximately to the 3-city airport I had to be sure and route my Northwest flights via Memphis. Thus I have no doubt that your Edge spends about 100X more time in AWD mode than one, say, here in Seattle. *** Weyerhauser box plant in Austin and a semi-conductor fabrication plant right there in Minneapolis.

MN....Hmmm..... Were it me I think I would seriously consider dumping, QUICKLY, that Edge in favor of something in the Toyota 4runner R/awd class. It appears that the Edge is not only not appropriate for off-road duty, but also not really appropreate for on-road use if driving on that road requires an extraordinary duty-cycle for the F/awd mode, rear drive engaged. One of these days someone will build a R/awd 4runner, or Cayenne, without the extra weight, useless weight 99.9999% of the time, of a "granny-grunt" low range gearbox/transfer case.

Retrospectively... "...sometimes the sound of grinding gears.." At this point you have now lost some of the PTO ring gear teeth. This has become, is being reported as, a very common failure of this(***) type of F/awd system. Too much use is made of the rear torque coupling, the PTO is overstressed, overheats, blows the seals and/or starts shredding gear teeth. *** Ford, Mazda, and now Venza, RX350, and Sienna. These later three are too new to know what the failure rate might be, become. Mazda, CX-7, seems to have put an end to their PTO failure rate via adding cooling (engine coolant) for the PTO.

"..This caused it to default to FWD..." Default, no, NOT. Except for two situations it is ALWAYS FWD. Number 1 situation...Acceleration from a stop or from a lower speed, <35MPH, to a higher speed. In this situation, with straight line acceleration, the F/R torque allocation/distribution might be as high as 50/50, tapering off to 100/0 F/R as speed increases, back to FWD mode. Even in a tight acceleration turn the coupling might be as high as 80/20 F/R. Number 2....Simply driving along, cruising along, at a relatively constant speed, ANY speed, and encountering front wheelspin/slip. In this case the rear drive will be instantly engaged, TC will also instantly activate, dethrottling the engine and "hammering" the brakes. Due to a simple matter of physics this latter situation is most likely to happen in lower speed ranges. Probably, maybe, even disabled above ~35MPH.

This doesn't make sense. There is NO "transfer" case but let's not be nit-pickly about "labeling". Your equivalent to a transfer case is the rear diff'l case. The torque "transfer" capability, a dual clutch, electromagnetics controlling a mechanical clutch, is housed within the rear diff''l case between the rear end of the drive shaft and the rear diff'l. "...the transfer case control module failed..." Could be, but if so that would be, more likely than otherwise, the end of the story. "... broken weld on a gear in the PTU..." There are NO welds within the PTU but that, again, is sorta picking nits. My guess is that the dealer replaced the control module as first effort, blind trouble-shooting technique, and when that didn't work started looking elsewhere. Ford is footing the bill so why bother to re-install the old control module. On the other hand a faulty control module might very well result in that rear clutch being engaged at times that it should NOT be and I think we already know that the weakest link in the "chain" in that case just happens to be the PTO/PTU. Overstressed, HEAT, the gear teeth begin coming off the ring gear. I would bet that PTO lube smelled HORRID.

Were I on the Ford design engineering team I night well design the F/awd firmware such that the colder it gets outside the more pre-emptively, higher level, more pro-longed, the rear drive would be engaged. Ford does the inverse of this with the FEH, as the OAT declines to freezing and below a lower and lower level of regenerative braking is used. "...wouldn't the fluid tend to get hotter..?? Consider the source. It is the additional stress of torque coupling to the rear driveline that is the primary source of heat within the PTO case. The lubricating fluid is the medium through which that heat is then conveyed to the interior PTO case surfaces. Looking back up that "chain" does the heating of the ring, pinion, and bearings lessen substantially if the case exterior is at 32F vs 85F. Hint: The rear drive is almost NEVER engaged when there is a substantial level of cooling air flowing past due to roadspeed.

Agreed, basically. With the stress added to the PTO with the rear drive engaged it will undoubtedly heat up. The metal case has a higher expansion ratio than the rubber (composite) seals and so.... And we could leave it simply at that, tolerance buildup under stress/heat....EXCEPT.. We are all aware, or CAN be, that Mazda addressed this very same issue via the addition of PTO cooling using the engine coolant system. Simple, the Ford engineers have screwed the pouch.

The PTO "couples" engine drive HP to the rear electromagnetic clutch ALL the time, CONSTANTLY. Engine torque is ONLY conveyed, thus HEATING the PTO, when that clutch is enaged. Otherwise the PTO is only along for the Ride, sorta like the rear wheels of a FWD vehicle.

"...but would this cause a leak...??..." PTO STRESS....YES...!! Stress = HEAT, heat means expansion of the volume of the PTO lubricating fluid, maybe even boiling of same........BLOWN SEAL. Catch 22, put less lubricating fluid in the PTO so fluid volume when HEATED doesn't exceed case capacity, COOLING effect of the fluid is also reduced. Lubricating fluid is the MEDIUM through which HEAT is conveyed from the PTO ring, pinion, and bearings to the PTO case for dissipation. Solution: Either reduce the functionality of the F/awd system (lower overall voltage duty-cycle to the rear drive engagement clutch) or provide additional cooling to the PTO as Mazda did.

With this Ford F/awd system, other than verifying, confirming, a proper level of current flow to the electromagnetic rear drive engagement clutch there's not much "self-check" that can be done.

Removing the correct, proper, fuse would undoubtedly disable the electromagnetically controlled rear drive engagement clutch. But you would still have the weight and friction of the PTO, driveshaft, rear clutch, diff'l, and the four rear halfshaft bearings/CVTs. Personally I would remove a front halfshaft and supply a constant current to the rear drive clutch and end up with a much safer RWD. Otherwise I wouldn't bother, IMMHO the rear drive isnt engaged often enough to really adversely affect FE considering the extra weight and friction remains. And considering you would end up with a PATENTLY UNSAFE FWD leaving it operative might just save someone's life.....YOURS maybe.

The F/awd operation other that automatically coupling the rear drive into the traction "mix" upon any low speed acceleration if slippage develops TC activation is INSTANT, braking the front wheels, dethrottling the engine and at the same time increasing the rear drive coupling to 100%, 50/50F/R. Reactively, NOT pre-emptively. Sounds SOP.

If you still have warranty coverage and considering the failure rate, seeming failure rate, of the PTO in this vehicle I would suggest getting the car to the dealer POST-HASTE.

Something positive.. Ford's rear electromechanical "linear" clutch approach to F/awd has proved itself so well that it has now been adopted for the new Toyota Venza, 2010 RX350, and even the new R/awd Porsche 911/997-2. Within a few years I expect we will see it in the Sienna and Highlander.

Other than taking BlazedUp's statement LITERALLY was there another way...? The way I read it it was anything but tongue in cheek and therefore with the DANGER someone might take the statement as valid. So I felt that a STRONG rebuttal was required.

There is NO vehicle known to mankind that will fit that criteria. At least no passenger vehicle for use on our public roads. That's the kind of over-confidence and immature attitude that gets F/awd/R/awd/4WD/4X4 drivers in a LOT of wintertime accidents. Out early to "play" in the snow. Snow is NOT for playing in except on foot, sled, or on skiis.

Simply turning the ignition off is more like closing IE, Internet Explorer, and then restarting it. Like a PC, A "true" "reboot" would involve turning off ALL power, disconnecting the battery for 10-15 minutes.

That sounds as if your transaxle was in two gears simultaneously, one of the clutches engaged when it shouldn't have been. That can happen as a result of one of the control solenoid actuators getting stuck either closed or open. Any small bit of debris in the ATF can be the cause and might NEVER reoccur.