Towing RV with AWD vs 4wheel

Towed a TT for 10 years with my AWD Durango. Dozens of trips every year. Never any problems. Now use the Durango as a daily driver. Going strong with 150,000 miles on it.

Yes, you need to know which one you have. GM has both gear and viscous
third members

The two guys I helped had vicous third members in their Escalades.

So the OP needs to ID which third member is in the vehicle


NVG 149 AWD transfer case info

BTW - GM says the viscous coupling is not serviceable. This doesn't mean the transfer case can't be fixed, just the viscous coupling needs to be replaced. This part is #2 in the first picture. So if you did happen to ruin the AWD tcase by doing a dyno, it can be easily fixed.

Escalade Awd

gm-trucks wrote:
the Escalade transfer case uses a viscous coupling type system to power the front wheels.
The vehicle is permanently in AWD, it can not be disconnected

Tahoe-Yukon forum: understanding Awd

FULL TIME AWD wrote:

NP3 (NV 149, BW 4473 viscous clutch): uses center viscous clutch to give front/back torque bias.

NVG 149 AWD transfer case info

performancetrucks wrote:
NVG 149 AWD transfer case info

How does viscous coupling work?

Viscous coupling is filled with silicone and is not computer controlled. A series of plates with holes and slots turn in the silicone fluid. Some plates are attached to the front axle driveshaft and some are attached to the rear axle driveshaft. Normally the plates turn at the same rate without relative motion. The silicone becomes very viscous as soon as it is heated by friction and shear caused by differences between the motion of the plates. This tends to lock the driveshafts. If the rear wheels and driveshaft are slipping and turning faster than the front, friction between the plates increases, slippage is reduced, the rear wheel spin is reduced and the torque from the input shaft is transferred to the front.

I had a 2005 GMC with the 6.0L, AWD, and 4.10 gears. Fuel economy was rough but it was a great truck and towed well. I liked having the AWD and not turning knobs when the tires spin.

We had a 2008 Yukon XL Denali with AWD, no problems with AWD. We were at the limits so have a 2500HD pickup now. Fuel mileage suffers some, it is not as good as 4wd system in bad conditions IMHO.

Google is your friend. 2006 burb uses a Borg Warner TC with planetary center diff. It will do fine.

AWD will be mor planted in wet roads etc.

I don't drive a GM, but my Ford is Auto 4x4, which just constantly checks for slip, and engages the transfer case when needed. Every so often when towing on wet surfaces you'll feel it engage, when starting from a stop, but it's a non issue. I'm at 100K miles, and the truck has seen probably 25K miles of towing. The selector has three options, auto 4x4, 4x4 hi, 4x4 low.

Here is one of the threads with a good diagram showing some of the
metrics of the four tires during a turn and how the third member
(along with the first and second) handle the different radii for each
tire

Before they invented it...they broke axles during the early days of
automotive vehicles

Folks who don't tow heavy will most likely NOT experience any problems,
but those who do tow heavy and in tough terrain...might...

Key difference is HIGH THROTTLE for loooong periods vs WOT bursts those
non-towing 'think' are comparable to towing heavy...in the hills...

What happened to those who helped walk through it...was that their
third member over heated or some such and barfed fluid


Accidentally Towed 100 Miles In 4WD
4x4radii 4x4radiuses thirdmember viscoustransfercase transfercase

benk wrote:


Not the same context.... Winter, snowy...so slippery...the exact
conditions 4x4 is to be used...vs...high traction conditions (not
slippery) that the OP drove and asking for info/help

4x4 (non full time) is NOT meant for good traction usage.

A good time to re-explain how 4x4 works for those who don't understand
or mis-understands.



rv.net thread: "4wd characteristics"


These images and hot links to info sites 'should' be self explanatory




4WD and AWD systems explained

Here is why full time 4WD can be used on pavement


Eventually you will break parts, expensive parts. All caused by driveline windup



Also, not absolute either (either good as new to busted to ruination)

There is middle ground (gray vs black/white).

That middle ground is also known as 'wear and tear'. The big question
is how far down that road is it. Again, it depends on how many curves
and their radius. Factor in how good was the traction & miles of it

travelnman wrote:
Anyone towing with AWD? Looking at a suburban with AWD, tow package,
cooling, 3.73 axel 2006 model year. Has the 6 liter V8. Would
rather have 4wheel I think. Anyone with advice before I buy would
be great. I'm towing 28 foot Springdale UVW 6,200lbs. What are
the disadvantages of AWD vs 4 Wheel?

Keep in mind there is a huge difference in pulling a light weight RV a few time a years vs a full time tow vehicle.
Also a 6200 dry weight may be closer to 8000 lbs after loading.
And also some may like their AWD vehicle although it didn't doesn't tow anything.

I did a quick Suburban/Tahoe google which brought up a bunch of those type forums which would be a great place to find answers from those folks that actually own the same exact AWD Suburban.

My Durango has full time AWD. However, I can flip a switch and have 4WD. On snow packed roads the AWD works great. Tend to use 4WD mostly when in deep snow or off road. If driving in winter conditions frequently or off road I would opt for part time 4WD.

That said, do any of today's bigger SUV's offer switchable AWD and 4WD like my old Durango has?

I towed with a 98 Explorer XLT 5.0 AWD for 2 years until I got a 06 Explorer Ltd 4.6 4x4. Comparing the 2 same chassis with similar engines I observed gas economy did improve because it was driven in 2wd mainly unless 4x4 automatically engaged when rear wheels slip. I also gain turning radius because I believe the front wheels turned tighter.

I prefer AWD because it is always on especially for when wife driving. The 4wd on Explorer just had auto 4wd hi and 4wd lo setting. It didn't have a 2wd only setting like my 03 Lincoln Navigator to lock out automatic engagement. When placed in auto the 4wd would engage with a jolt but I didn't have any failures in 80K miles of use.