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Discussion Starter #1
I keep seeing ads for Escalade ESVs that have AWD. Since they ride the same platform as Suburbans / Yukon XLs with 4WD, I have to ask - is this merely a misnomer, where the Escalade has the same 4WD system as the Suburban and Yukon XL, or does the Escalade really have an all wheel drive system that its less flashy stablemates don't get?

And if it is really AWD, is there anything I ought to know about it before considering it? (To give you an example, we've been considering getting a Toyota Sienna, in addition to a Suburban. It comes in FWD and AWD versions. People roundly complain about the AWD versions because they require expensive run-flat tires due to the AWD system components gobbling up the space that otherwise stores the spare tire on FWD models, and they say that the AWD Siennas tend to eat a set of tires every 20,000 miles or so. I definitely don't want that. Plus, they say that if the tires are not a matched set, the AWD system will basically brick the van, at least until the tires are changed to a matched set, because it detects differences in wheel spin speeds. I don't want to have to get a new set of run-flat tires just because one gets irreparably damaged.)
 

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The escalade has a spare tire and yes they are full time AWD. People would be complaining about the harsh mileage compared to a 4x4 or rwd. Otherwise they ride nice. I think gm was thinking if people buying the top of the line expensive truck they are not really caring about mileage and made them all AWD. as far as I know they never came in 4x4's. I know of at least 1 person who converted an Escalade into a 4x4.

All vehicles that are 4x4 or awd require all the tires to be the exact same size and pumped up to the same psi, they also require a full size spare.

There is no comparison between a sienna and the Escalades/Burbs/Yukons or Hoes. These are drastically different vehicles.

Al
 

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As Al says, they are different vesicles.

The AWD in the Caddy operates very much like the AWD selection in the Chevy; however, the transfer cases are different, the front axle assembly is different, there is no selector switch in the Caddy.
 

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playing around on their build your own website years ago, some of the ESVs did not get a spare tire. I think it was something to do with the exhaust. I assume it got the cheap-o fix-a-flat kit that a previous Malibu work car had instead of a spare doughnut.
 

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So nobody yet mentioned the real useless piece of bullshit with the Escalade/Denali AWD. NO LOW RANGE! I would never touch a Lade or Denali for that reason alone.
 

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Discussion Starter #6
So nobody yet mentioned the real useless piece of bullshit with the Escalade/Denali AWD. NO LOW RANGE! I would never touch a Lade or Denali for that reason alone.
I guess that's not a big deal for me. I've had two vehicles with 4WD (1996 Tahoe and 2004 4Runner) and I've never used low range. I don't want 4WD for off-roading; we do a lot of winter driving and I use it when the road conditions are nasty.
 

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I guess I'm the same, my vehicles go off road (well, off asphalt roads), I hunt and fish and use logging roads and dirt paths when I do hunt/fish.
I live in Canada and we have our fair share of snow and freezing rain and 4x4 gets used when the G80 isn't enough.
And ya know, I can only recall one time when I used 4low.
 

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I’m with @RayVoy. With the g80 going camping and fishing on logging roads, I’ve only used 4-Lo once, and I was being manly and impulsive (the wife’s words were “don’t”). I like knowing it’s there if needed but I think knowing I didn’t have it I would probably be less aggressive on the dirt

8FA4B837-55BB-4B6A-869E-4A7FDC10CA3F.jpeg
 

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My Yukon XL has the following choices: AWD, 4 HI, 4 LO, and 2 HI. I like choices, and avoided Denali and Escalade because the operate in AWD only.
 

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Discussion Starter #10
My Yukon XL has the following choices: AWD, 4 HI, 4 LO, and 2 HI. I like choices, and avoided Denali and Escalade because the operate in AWD only.
Fascinating. So there's a switch that engages AWD as well as the regular switch to toggle between 2WD, 4 HI, and 4 LO? I haven't seen that yet... not that I've looked all that hard...
 

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It's a feature in the electronic transfer case. When AWD is selected, the case is shifted into 4hi; however, a clutch pack is used to keep power from going to the front axles until there is rear wheel spin, at that point, the clutch pack releases and powers the front axle.
The AWD t-case works the same way, but without the selector switch.
 

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Ditto on the hardly used 4Lo.

For the novice reader: 4WD should be used to get you out of trouble instead of seeing how deep you can get into it. Definitely refrain from using 4Lo as much as possible.

Side note: I did use 4Lo to help teach my kids how to drive a manual trans truck. I had them practice while I was pitching hay bales. 4Lo in 1st gear is walking speed and they had a hard time killing it in the hay meadows, so it was a good teacher.
 

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DO NOT USE the AWD on the standard 4WD transfer case. It is a poorly designed clutch pack the overheats and burns up. Countless, countless cases of failures from folks who thought "oh, cool, I can just leave it AWD and get the best of both worlds". Go ask any mechanic who works on these things.

I use 4lo often. Sometimes it's as simple as moving my camper for the first time in the spring when the tires have sunk about 4" into my yard. There are also the times when I get my plow truck stuck in a snowbank in my yard and need to pull it out by myself. 4lo is the way to go then.
 

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Fascinating. So there's a switch that engages AWD as well as the regular switch to toggle between 2WD, 4 HI, and 4 LO? I haven't seen that yet... not that I've looked all that hard...
Here’s what it looks like on the dashboard.
8B72E435-5EB2-4A96-9335-32CF897F64BB.jpeg
 

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Discussion Starter #15
Here’s what it looks like on the dashboard.
View attachment 135776
So does this mean that the vehicles on this platform that have "AWD" (such as the Escalade ESV) actually don't have all wheel drive; rather, they have a doctored part-time 4WD system, reminiscent of the system in the Volkswagen Vanagon Syncro, that engages the front wheels when the rear wheels slip?

To me, AWD means that all four wheels are powered all the time.
 

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No AWD vehicle has equal power at all 4 wheels all of the time.....things will break.

Let's say your turning a circle on a hard paved surface, when you turn, all 4 wheels are turning in a different sized circle.
If you had all four wheels solidly tied together they will each be fighting the other three.
The system GM commonly uses, allow for open diff turning at each axle and allows slippage in the transfer case.

To be fair, GM has used other transfer cases in trucks, the Trailblazer SS which used the 6 ltr engine had a Torsen T3 differential as a transfer case.
However, this case did the same function, it controlled the power going forward and turned off the front power when it was necessary.
 

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Discussion Starter #17
No AWD vehicle has equal power at all 4 wheels all of the time.....things will break.

Let's say your turning a circle on a hard paved surface, when you turn, all 4 wheels are turning in a different sized circle.
If you had all four wheels solidly tied together they will each be fighting the other three.
The system GM commonly uses, allow for open diff turning at each axle and allows slippage in the transfer case.

To be fair, GM has used other transfer cases in trucks, the Trailblazer SS which used the 6 ltr engine had a Torsen T3 differential as a transfer case.
However, this case did the same function, it controlled the power going forward and turned off the front power when it was necessary.
I never said that all four wheels were equally powered at all times. But if it's engineered for there to be some slippage in the transfer case, why then is it important for all four tires to be the same size (as in, matched for amount of wear) and pressure? Wouldn't a "slippy" transfer case take care of any small inconsistencies in tire size without damage?
 

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I love this old video that explains how a differential works. So this is also how an AWD vehicle works just like Ray said, there is no clutch packs or any of that, it is simply an open differential in place of a transfercase.

Al

 

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The owners manual does say that al tires should be equal; but, I agree with you that the built in slip should allow for some wear.
After all, the only time you need AWD, or 4x4, is when it's slippery and the slippery surface would allow for the wheels to turn without any binding when AWD engages.
 

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The AWD Caddy is all wheel drive not 4 WD. I have an 03 Tahoe with the earlier version of the AWD system that was standard on the Caddy's back then. There is no selection for 2 WD operation. You have a choice of 4 low without stabilitrack, Standard AWD operation with Stabilitrack, Standard AWD operation without Stabilitrack and Neutral. The early models didn't use the limited slip diff. I think the newer models do use a limited slip diff. My Tahoe uses the Traction Control system to limit wheel spin instead. As grip changes from one wheel to another power is transferred to the wheels that have the most grip. The system works well. I have owned the Tahoe since December 2002 and have put 124K miles on it with a fair amount of long distance trailer towing with 5600 lb to 6600 lb car trailers. I have had no drive line issues.

Here is a picture of the dash switch on my Tahoe:
165693


Here is a description from the factory service manual of how the transfer case works:
Transfer Case Description and Operation
The Borg Warner (BW) model 4482 NR4 transfer case is a two-speed, full time 4WD, transfer case. The transfer case has an external planetary type differential, which has two different sets of pinion gears. The planetary differential provides a 40/60 torque split front/rear full time. This means the front and rear propeller shafts are constantly being driven for maximum traction in all conditions.
While in the 4HI mode, the transfer case external type planetary differential functions the same as a typical rear axle differential. The transfer case differential pinion gears function as the spider gears, and the sun gears function as the side gears.
The following actions occur because of the planetary differential:
If the vehicle is on a hoist, and in the 4HI mode, the front propeller shaft can be rotated by hand.
The vehicle cannot be driven in the 4HI mode if one propeller shaft is removed.
Operating the vehicle on the hoist, in the 4HI mode, can damage the differential pinion gears, by over-spinning.
Operating the vehicle with one propeller shaft removed, in the 4HI mode, causes over-spinning of the differential pinion gears.
The BW 4482 design of the planetary differential allows use with the Vehicle Stability Enhancement System (VSES) vehicles. The VSES takes use of the planetary differential, by applying braking to a tire that has less traction and dividing the engine torque to the other axle. A high/low planetary carrier assembly provides the high and low ranges, which is a 4-pinion gear, sun gear, and annulus gear arrangement, giving a 2.64 low range reduction ratio.
The BW 4482 case halves are high-pressure die-cast magnesium. Ball bearings support the input shaft, the front output shaft, and the rear output shaft. A needle roller bearing is located inside of the input shaft gear to support the front of the mainshaft. The rear of the mainshaft is supported by a bronze bearing inside the rear output shaft. The transfer case requires DEXRON®III ATF Fluid GM P/N 12378470 (Canadian P/N 10952622), which is red in color. An oil pump pumps the fluid through the mainshaft oil gallery to the gears and bearings.
Transfer Case Shift Control Switch
The BW 4482 transfer case features a 3-button shift control switch located on the instrument panel. When the vehicle has the ignition key in the RUN position, the transfer case shift control module starts monitoring the transfer case shift control switch to determine if the driver desires a new mode/range position. At a single press of the transfer case shift control switch, the lamp of the new desired position will begin flashing to inform the driver that the transfer case shift control module has received the request for a new mode/range position. The lamp will continue to flash until all shifting criteria have been met and the new mode/range position has been reached, or has been engaged. Once the new mode/range position is fully active, the switch indicator lamp for the new position will remain ON constantly. In addition, the switch includes a VSES request button which sends a voltage signal to the transfer case shift control module. The transfer case shift control module in turn sends a request via the class 2 data bus to the ABS control module which controls the VSES system.
During normal driving situations, the transfer case operates in the 4HI mode. When the 4HI mode is selected, the transfer case shift control module sends 12 volts to an electrical motor, which is the transfer case encoder motor. This motor rotates the transfer case shift detent lever shaft which moves the shift forks and range sleeve to obtain different modes/ranges.
The BW 4482 transfer case has the added feature of also providing the driver with 2 selectable mode/range positions and a VSES request button:
4HI - Full Time 4 Wheel Drive
4LO - 4 Wheel Drive Low Locked
VSES - Vehicle Stability Enhancement System
The transfer case will not allow a shift into or out of 4LO unless the following criteria has been met:
The engine is running.
The automatic transmission is in Neutral.
The vehicle speed is below 5 km/h (3 mph).
This transfer case also has a Neutral position. A shift to the Neutral position allows the vehicle to be towed without the transmission output shaft rotating. Refer to the Owners Manual for instructions for proper towing of the vehicle.
Neutral position may be obtained only if the following criteria have been met:
The ignition switch is ON.
The automatic transmission is in Neutral.
The vehicle speed is below 5 km/h (3 mph).
The transfer case is in the 4HI mode.
Once these conditions have been met, press and hold both the VSES and 4LO Lock buttons for 10 seconds. When the system completes the shift to neutral, the red neutral indicator will illuminate.
4HI Mode Power Flow
When the BW 4482 is in 4HI mode, the engine power flows from the transmission to the input shaft (1). The input shaft (1) is connected to the mainshaft (3) by the high/low range sleeve (2). The high/low range sleeve (2) outer teeth are engaged with the input shaft (1) high-speed teeth. The range collar is slip splined to the mainshaft (3). The mainshaft (3) delivers the power flow to the planetary differential (6), which splits the torque 40 percent through the front differential pinion gears (5) to the front sun gear (10). The torque to the front axle then goes through the drive sprocket (4), via the chain (11) to the front output shaft (12) and to the front axle. The differential planetary splits the torque 60 percent to differential rear pinion gears (9) and rear sun gear (7). The rear sun gear is connected to the rear output shaft (8) and the torque flows to the rear axle.
4LO Lock Mode Power Flow
When shifting the transfer case to the 4LO Lock mode, it commands the encoder motor (12) to turn the shift detent lever shaft (13), to rotate the shift detent lever cam (16). There are two cam profiles on the shift detent lever cam (16) functioning at the same time. The range profile on the shift detent lever cam (16) moves the high/range shift fork (18) and the high/low range sleeve (4) rearward to the 4LO range position.
The mode profile on the shift detent lever cam (16) moves the mode shift fork (17) rearward along with the mode shift collar (6).
The high/low range sleeve (4) outer teeth disengage from the input shaft (1) high-speed teeth. The high/low range sleeve (4) outer teeth then engage in the high/low planetary carrier teeth (19). The power flow is now from planetary teeth on the input shaft (1) to the planetary gears (2) in the carrier. Rotating the planetary gears, which are engaged in the annulus gear (3), rotates the planetary carrier. The planetary carrier delivers the power to the high/low range sleeve (4). The high/low range sleeve (4) then drives the mainshaft (5), providing a 2.64:1 reduction to the speed of the mainshaft (5).
The mode shift collar (6) locks the mainshaft (5) to the drive sprocket (7). Torque is sent by the chain (14) to the front output shaft (15) and to the front axle.
The rear propeller shaft power flow is delivered by the case of the planetary carrier (8) being splined to the mainshaft (5). The power flows from the planetary carrier case to the rear pinion gears (11), to the rear sun gear (9), and to the rear output shaft (10).
The torque distribution in this mode is now determined by vehicle dynamic conditions and weight distribution. The planetary differential (8) is not operating, and both the front and rear propeller shafts are being driven at equal RPMs, therefore giving a 4 low lock mode. This mode should only be used for extra traction during off road use. Using this mode on dry pavement will cause tire scuffing.
Neutral Mode Power Flow
Shifting to the neutral position, the high/low range sleeve is centered between the input shaft and the high/low planetary carrier. The high/low range sleeve is not engaged with either the input shaft or the high/low planetary carrier teeth. The planetary differential is in the 4HI mode.

Here is a link to a YouTube video published by Borg Warner showing how the transfer case works to transfer power from one axle to the other:
 
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