Off Road Drving with AWD

[Baban]

Hi ladies and gents!

I was just wondering if AWD is good for hardcore off roading (Mountains, Desert...etc)

Ive got an edge and i am really excited about off roading but im worried it might not be as strong as it is on the road

[DJ Starr]

What you have is, imo, an expensive large car/small truck (don't feel bad, I have one too). What we don't have is an offroader. I love my Edge but I am not going rock crawling anytime soon.

 

About the biggest risk I will take is the local campground......

 

If you want to go mudding, buy an 90's sidekick (probably 1k or close) add some 35's and run it hard. Who cares if it gets schmucked up?

[blu by u]

I would imagine the Edge is decent in an off road capacity but not great. Not much ground clearance and improper tires would be the biggest challenges but AWD coupled with the type of HP we have, I would think it would handle moderate terrain.

 

These are built for cruisin moreso than muddin...

[Ksaness07Edge]

I would agree with both blu by u and DJ Starr if you want a true off roading/rock crawling/ mudding vehicle get something different but if you want to take it out to the sand dunes or on some light trails I think it will handle itself very well.

[3 Bar Grille]

Perhaps you should of picked up a Hummer H3 instead...?

[edgesenior]

..............Off Road?...........Son are we talkin'... L.A. ? ............ Lower Alabama.........Happy..... ..............Sr.........

[rboe]

Not having a low range should tell you something right there. The purdy looks is the second clue. Not having a body on frame chassis is the final nail in the coffin.

 

The four wheel drive is good for snow and inclement (sp?) weather and that is about it.

 

But a true off-roader in this size, only a bit uglier so we don't have to worry about woodland rash (say, a 1946 Dodge Powerwagon - a truely handsome vehicle in its' own right) from Ford would be pretty sweet.

[TL Kelly]

The owner's manual has quite a bit of cautionary verbage on off-roading. It pretty much states the Edge isn't built for off-roading and specifically states it is not and does not perform like a 4WD and should not be used for off-roading. I would bet they would want to deny any warranty repairs if they believed the damage was due to off-road driving. Some of the comments talk about the AWD system being prone to overheating and damage if you get into exessive wheel spin. I haven't had a chance to read up on the power distribution system but I would think it is fluid driven like an auto transmission instead of gear driven like an old fashioned transfer case and a lot of continued power transfer under rough conditions could be hard on it. I won't be climbing any mountains with my wife's Edge.

[wwest]

The owner's manual has quite a bit of cautionary verbage on off-roading. It pretty much states the Edge isn't built for off-roading and specifically states it is not and does not perform like a 4WD and should not be used for off-roading. I would bet they would want to deny any warranty repairs if they believed the damage was due to off-road driving. Some of the comments talk about the AWD system being prone to overheating and damage if you get into exessive wheel spin. I haven't had a chance to read up on the power distribution system but I would think it is fluid driven like an auto transmission instead of gear driven like an old fashioned transfer case and a lot of continued power transfer under rough conditions could be hard on it. I won't be climbing any mountains with my wife's Edge.

 

When Ford discovered that the numerous PTO/PTU failures were due to driver misuse (over-use..??) of the F/awd system they "retuned" the control firmware to make the system less useful. Less useful, less stress on the drive train, no PTO overheating, fewer failures. Mazda, CX-7, on the other hand, went to cooling, engine coolant flow, of the PTO as a solution.

[akirby]

When Ford discovered that the numerous PTO/PTU failures were due to driver misuse (over-use..??) of the F/awd system they "retuned" the control firmware to make the system less useful. Less useful, less stress on the drive train, no PTO overheating, fewer failures. Mazda, CX-7, on the other hand, went to cooling, engine coolant flow, of the PTO as a solution.

 

Source?

[wwest]

Source?

 

The readily available historical record, F/awd design evolutionary record, here and there on the internet.

 

Start here:

 

http://www.fordedgeforum.com/index.php?showtopic=1654

Edited November 19, 2009 by wwest

[akirby]

The readily available historical record, F/awd design evolutionary record, here and there on the internet.

 

In other words, you have no source from Ford that says they had to detune the rear drive engagement.

Edited November 20, 2009 by akirby

[wwest]

In other words, you have no source from Ford that says they had to detune the rear drive engagement.

 

So, you think that "beefed up", made the PTO more robust...??

 

Then why not go back to allowing the driver to "lock" the system in F/awd mode. Maybe even put the thermistor back in to warn the driver of impending overheating...??

 

Back when the electromechanical linear coupling clutch was subject to overheating what did Ford do to alleviate the problem so the thermistor could be eliminated. Take the manual lock ability away..??

 

Then the NEXT weakest link began to fail, the PTO....

 

Mazda apparently had, or foresaw, the need for cooling the PTO and did so. Just what do you think Ford did when the PTOs began to fail.. if not detune/derate at some level..??

 

And if Ford did detune/derate the F/awd functionality how would users EVER KNOW.

 

 

Oh, keep in mind that detuning/derating the F/awd functionality via new firmware "FLASH" is something that can be done in the field, by the dealer, without ANY customer knowledge, as the replacement PTO is being installed.

[akirby]

So, you think that "beefed up", made the PTO more robust...??

 

Then why not go back to allowing the driver to "lock" the system in F/awd mode. Maybe even put the thermistor back in to warn the driver of impending overheating...??

 

Back when the electromechanical linear coupling clutch was subject to overheating what did Ford do to alleviate the problem so the thermistor could be eliminated. Take the manual lock ability away..??

 

Then the NEXT weakest link began to fail, the PTO....

 

Mazda apparently had, or foresaw, the need for cooling the PTO and did so. Just what do you think Ford did when the PTOs began to fail.. if not detune/derate at some level..??

 

And if Ford did detune/derate the F/awd functionality how would users EVER KNOW.

 

 

Oh, keep in mind that detuning/derating the F/awd functionality via new firmware "FLASH" is something that can be done in the field, by the dealer, without ANY customer knowledge, as the replacement PTO is being installed.

 

If that was the fix then the seal would not need to be replaced and the TSB would mention the reflash. Does the TSB mention a reflash?

[wwest]

If that was the fix then the seal would not need to be replaced and the TSB would mention the reflash. Does the TSB mention a reflash?

 

 

Speaking of instances wherein the PTO was replaced, not just the seal.

 

Anyone have an answer, looked at the TSB calling for PTO replacement.

[Waldo]

Mazda apparently had, or foresaw, the need for cooling the PTO and did so. Just what do you think Ford did when the PTOs began to fail.. if not detune/derate at some level..??

 

And if Ford did detune/derate the F/awd functionality how would users EVER KNOW.

 

 

Oh, keep in mind that detuning/derating the F/awd functionality via new firmware "FLASH" is something that can be done in the field, by the dealer, without ANY customer knowledge, as the replacement PTO is being installed.

 

Ford's just as smart as Mazda, they are doing exactly what you describe on the Ecoboost versions which use exactly the same hardware. In fact I even beleive they will use a water-cooled PTU on the new Explorer. But the problem with the leaking seals is not due to temperature, it's purely mechanical tolerances.

[wwest]

Ford's just as smart as Mazda, they are doing exactly what you describe on the Ecoboost versions which use exactly the same hardware. In fact I even beleive they will use a water-cooled PTU on the new Explorer. But the problem with the leaking seals is not due to temperature, it's purely mechanical tolerances.

 

When, what model year, did Ford start using engine coolant for cooling for the PTO..?? Or are they only using it for the TwinForce engines due to the extra driveline stress...??

 

"..purely mechanical tolerances..."

 

Yes, PTO ring and pinion, lube, and case HEAT-UP, mechanical tolerances change beyond design expectations....

[igcitng]

I wanna know if the original poster ever went offroading. I would pay to see that.

 

Doesn't Ford own Mazda? One in the same.

[akirby]

Doesn't Ford own Mazda? One in the same.

 

Nope. Never did. They owned 33.4% of Mazda at one time but now it's down to around 10%. But they still work together.

[Waldo]

When, what model year, did Ford start using engine coolant for cooling for the PTO..?? Or are they only using it for the TwinForce engines due to the extra driveline stress...??

 

"..purely mechanical tolerances..."

 

Yes, PTO ring and pinion, lube, and case HEAT-UP, mechanical tolerances change beyond design expectations....

 

The next Explorer, 2011. As I posted, the issue is in the tolerance of the bearing that holds the linkshaft, the one that hangs off the engine about a foot away from the PTU. Not really related to the heat in the PTU at all.

[wwest]

The next Explorer, 2011. As I posted, the issue is in the tolerance of the bearing that holds the linkshaft, the one that hangs off the engine about a foot away from the PTU. Not really related to the heat in the PTU at all.

 

 

The way I "read" the posts it is the passenger side PTO halfshaft seal that is being "broached". The driveline to the passenger side front wheel goes through the PTO and therefore it is the PTO lube that "broaches", leaks from, the seal.

 

Am I wrong..??

 

When did Ford first know they had an overheating problem with this F/awd system...2007..??

 

Now, finally, a fix...2011.

 

I'm anxiously/hopefully looking forward to the Sport Trac version of the 2010 unibody Explorer.....

Edited November 24, 2009 by wwest

[Waldo]

The way I "read" the posts it is the passenger side PTO halfshaft seal that is being "broached". The driveline to the passenger side front wheel goes through the PTO and therefore it is the PTO lube that "broaches", leaks from, the seal.

 

Am I wrong..??

 

When did Ford first know they had an overheating problem with this F/awd system...2007..??

 

Now, finally, a fix...2011.

 

I'm anxiously/hopefully looking forward to the Sport Trac version of the 2010 unibody Explorer.....

 

I assume you mean "breach", not "broach". Yes the seal is leaking, but the cause is sideload, not temperature. The driveshaft is pushing down (or up, or sideways) on the seal because the shaft is not located correctly. Over (a short) time, this extra load that the seal was not designed for causes it to fail. This is exactly like the failure of a "blown" shock, the seal is sideloaded and eventually fails, causing the fluid and gas to leak out. Think about it, even when overheated, PTU oil won't get over 160 degrees (the system shuts down at 145 I think). Engine oil and coolant will see temperatures far above that on a regular basis and you don't hear about seal failures on those parts.

 

I still don't understand why you think there's a temperature "problem". Temperature is always a concern and is considered in the design of the system. Look underneath an Ecoboost Flex and you'll see a duct that blows fresh air right up to the PTU. The Explorer needs additional cooling because it's expected to have a more severe life including off-roading.

 

PTU temperatures are a design challenge. But Ford has addressed the issue from the beginning, which has prevented it from being a problem.

[wwest]

I assume you mean "breach", not "broach". Yes the seal is leaking, but the cause is sideload, not temperature. The driveshaft is pushing down (or up, or sideways) on the seal because the shaft is not located correctly. Over (a short) time, this extra load that the seal was not designed for causes it to fail. This is exactly like the failure of a "blown" shock, the seal is sideloaded and eventually fails, causing the fluid and gas to leak out. Think about it, even when overheated, PTU oil won't get over 160 degrees (the system shuts down at 145 I think). Engine oil and coolant will see temperatures far above that on a regular basis and you don't hear about seal failures on those parts.

 

I still don't understand why you think there's a temperature "problem". Temperature is always a concern and is considered in the design of the system. Look underneath an Ecoboost Flex and you'll see a duct that blows fresh air right up to the PTU. The Explorer needs additional cooling because it's expected to have a more severe life including off-roading.

 

PTU temperatures are a design challenge. But Ford has addressed the issue from the beginning, which has prevented it from being a problem.

 

 

Broach:

 

http://74.125.95.132/search?q=cache:5BWqC9...=clnk&gl=us

 

"..engine oil and coolant..."

 

Both of those have lots of extra room for expansion due to heat, whereas the PTO is virtually hermetically sealed.

 

"..get over 160 degrees.." "...shuts down at 145.."

 

Many posters seem to think the thermistor has been eliminated, seemingly at the same time as the manual control switch. Besides which the thermistor was in the rear diff'l case, was it not...??

 

And I rather doubt that Ford will market the new unibody Explorer as off-road ready/worthy, especially if equipped only with the Venza type F/awd like in the Escape, etc. Plus that is not where the majority of the market lies, most buyers are simply looking for additional wintertime on-road stability and traction.

 

And doesn't a TRUE off-roader expect/demand a granny grunt low gear range that would require a transfer case implementation.??

[Waldo]

I didn't know "broach" could refer to piercing, so if that's the case then no, the issue is not broaching. The seal is not getting pierced, it's getting compressed.

 

A PTU is not hermetically sealed, there is a breather vent and besides, it's not full. There's still plenty of air in there as the fill level is only about 2/3rds of the way up. Besides, the vast majority of the leaks are actually transmission fluid leaking out, not the PTU grease. That's the same transmission fluid that passes through the transmission cooler by the way.

 

The new Explorer will feature a specific off-road and hill descent mode, marketing specifically towards off roading. It also has higher ground clearance and beefed up suspension to meet Ford's off-road standards. If you want a non-off-road 7 passenger vehicle, Ford already has the Flex.

[wwest]

I didn't know "broach" could refer to piercing, so if that's the case then no, the issue is not broaching. The seal is not getting pierced, it's getting compressed.

 

"pierced" doesn't have to mean a solid object...

 

A PTU is not hermetically sealed, there is a breather vent and besides, it's not full. There's still plenty of air in there as the fill level is only about 2/3rds of the way up. Besides, the vast majority of the leaks are actually transmission fluid leaking out, not the PTU grease.

 

The way I read the posts both the inner and outer PTO seals are blowing out then the ATF is leaking out of the self-same seal AFTER the PTO's 70 weight is all gone or mixed in/with.

 

That's the same transmission fluid that passes through the transmission cooler by the way.

 

The new Explorer will feature a specific off-road and hill descent mode, marketing specifically towards off roading. It also has higher ground clearance and beefed up suspension to meet Ford's off-road standards. If you want a non-off-road 7 passenger vehicle, Ford already has the Flex.

 

 

"hill descent mode" simply uses, and OVERHEATS, the brakes automatically rather of one's own foot power.

 

No "true" off-roader worth their salt would be interested in anything less that a 4WD/4X4 with a transfer case.

 

No even remotely involved in the sport but IMMHO the 4runner would be the minimum "fit".

 

The Ford Flex...off-road....??!!

Edited November 26, 2009 by wwest