AWD question

[HSpiering]

AWD question?? My daughter got a Durango. Has a knob AWD or FWD. So what is the difference or benefit between all wheel drive and 4 wheel drive? I never had an all wheel drive .
No sure I understand the gear change. Driving down a snow covered road, to me it would look to be the same.

 

[RustyJC]

If FWD stands for 4WD and not front wheel drive (which it shouldn't stand for the latter on a Durango), the difference between AWD and 4WD is that the transfer case has a differential on an AWD vehicle that allows the front and rear wheels to rotate at different speeds in turns; the 4WD does not which results in the scrubbing that a 4WD vehicle experiences on dry pavement when turning. Since the Durango has both options, the AWD setting keeps the transfer case differential open; the 4WD setting locks it.

In other words, the AWD setting can be used on dry pavement (think Audi Quattros and Subarus), while the 4WD setting should not be used on dry pavement.

Rusty

 

[DonFitzwater]

If the transfer case operates like I think it does, DON'T run it in AWD. There is a clutch system that is electrically controlled and disengages and engages via the PCM and is engaged when wheel spin occurs. This design is crap in my opinion. It's hard on driveline and more importantly, the transfer case. I've been through several chevys recently that have a similar system and it's amazing how much longer the transfer cases last when just put in 4WD compared to AWD.

Of course, if the roads in your area are snow free the majority of the time, the AWD setting would be ok as the auto shifting would be kept to a minimum.

 

[RustyJC]

I guess it all depends. I had a 1990 Ford Aerostar with the 4.0L V-6 and the AWD system. It had the electronically-controlled clutch pack in the transfer case and never gave any problem - the front CV joints were another matter..... :{

Rusty

 

[HSpiering]

DFitzwater

Don't think that will work. It looks like only two choices you are in AWD or you are in FWD. I'm not sure it has a way to free spin the frown axel. Not that sure how this works on her Durango. Unless you are talking about driving on snow with the two choices?

What stared this was I lift a wheel of the floor to look at it and it did not turn. She said the RWD light on the dash would sometimes come on and off. I'm thinking like a lose wire ore switch may be bad. That was the first problem. Just trying to figure how this works.
Not sure why the light plinks on some times in AWD.

 

[DonFitzwater]

Alot of the operational issues with these systems are caused by the ABS system. They use the wheel speed portion of the abs to figure out wheel slip. First things first, check all the grounds you can find and take a good look at the wheel speed sensors and tone rings. Also, check the wires near the sensors for damage.

 

[HSpiering]

I did see her battery ground was corroded bad. I didn't take it all the way off. I did try to clean on some. Not sure that would be a ground problem for the FWD light. Don't know if she has other issues.