I have a GMC 4x4 with part time(manual) 4 wheel drive. We had a snow storm here in the northeast and i had to get to,and back from a hospital about 12 miles away. the roads were not plowed and had about 2- 3 inches of slushy,slippery mush most of the way. i put the truck in 4 wheel drive for the larger part of the trip,and then shifted out when i was on somewhat hard packed snow and then back as conditions dictated.
My concern is if i drove in 4 wheel for too long under the described conditions? This the first time i have used the 4x4 feature.
Thanks

 

You should be fine. Remember 4x4 is used for more than just snow. Up here we sometimes have to 4x4 just to get to a friend's house :-)

 

Yeah! Sometimes its a required to get around.
Thanks for the reply

 

As long as you are on road conditions that will allow the wheels to slip there shouldn't be any problems. Extended high speeds probably wouldn't be good either

 

Thanks for the reply. I have a better feeling for the use of 4 wheel drive.
Defintely on dry pavement is a no-no. Would speeds around 40 mph be considered high speed on any road conditions?

 

only if you loose control

The main thing is to not have 4 wheel engaged on dry pavement.

 

If you can't drive in snow in four wheel drive, what good is it? You are fine.

As long as your tires are the same size on all four wheels, driving on hard packed snow is going to be no problem in 4 wheel drive. At speeds up to normal highway speed even.

The biggest problem is when you turn the front wheels all the way, say when parking, the system tends to bind up on itself.

Most newer GM manual transfer cases have 5 settings: 4 wheel auto - which is used for intermittent slippery conditions. 4 wheel high - used for snow or offroad conditions. 4 wheel Low - low range of gears used for very heavy offroad conditions. 2 wheel - used for clear conditions. And Neutral.

There is typically an electric motor that shifts the transfer case between the settings. The motor itself is the weak link in the system - and it is very expensive to repair.

Just FYI - I know this stuff because my motor recently went out on a trip to Florida and I drove my Suburban back 1100 miles on dry roads in 4 wheel auto - it caused no damage, but the shift motor had to be replaced

 

have you read the owners manual?

although minimized and somewhat simplistic, the manual generally explains the when's where's why's and how's for the given vehicle.

It sounds as if you are conscientious enough that you shoudl not need to worry about doing damage to the vehicle. You have grasped the basics and are employing the reasoning behind the different drive options quite well.

 

Thanks guys/girls for your input.
I did read the manual ,but had concerns,especially with the manually shifting in and out of 4 wheel high on the move, I think GM and other manufactures refer to it as "shift on the fly". My experience with 4 wheel, many years ago,was you had to stop the vehicle to shift in and out otherwise you could trash the drive.

 

4 wheel ought to be engaged on a monthly basis to promote lubrication. Warn hubs recomends 1/2 mile in 4 wheel drive at least once a month.

I've always been leary of engaging 4 wheel on the fly. I doubt I ever engage mine at speeds much over 5 mph but then I also tend to drive older 4x4's.

 

Got a Jeep Cherokee 4x4 that specifically says "engage any 4 wheel drive setting except 4 wheel low at at any legal speed" 4 wheel low should only be engage while going very slowly.

The point is, at least on the Jeep, you MUST be moving for transfer to or from 4 wheel drive to take place.

 

Sorry for replying earlier,but for some reason messages from here are getting into my mail box. I'm getting other mail though.

Gm says you can engage 4 wheel high at speeds around 30 mph while moving in or out of gear. 4 wheel low you must stop,shift into neutral then shift in or out.

 

Not so on my '90 cherokee, I can move the lever at a dead stop and 4 wheel will be engaged with in 1' of rolling. Jeep has 2 different transfer cases, select trac [2 different 4 wheel high selections plus 4 wheel low] and quadra trac [1- 4 wheel high and 1- 4 wheel low]

Only the "green" 4 wheel high [select trac only] is recomended for dry pavement.