I rarely drive on anything other than well-maintained roads. I try to remember to shift into 4H once in a while just to keep things stirred up in the t-case and front diff. Is that a good thing? should I also use 4L for a bit too?
How often and for how long should I shift into 4WD just so that when the time comes that I need it it is available?
It is a good idea to do this as it lubricates the parts that are not turning as well as the motor parts. You should this once every 3 months IMO. It doesn hurt to shift it into low range as well. You don't need to drive it more than a half block and you should not drive it more than that on the pavement.
The worst thing you can do to a transfer case id to leave it in 2 high for a year or more. The contacts in the switches and motor can become contaminated with fine particulate and this is what causes them to fail.
Jim
2004 SILVERADO 2500HD LS
Pro Comp Leveling Kit
285-75-16 Cooper ST All Terrains
Pro Comp Programmer
Bilstein Shocks
Linux Bed Liner
Tinted Windows
Other rides:
1967 Landcruiser <350 Chevy>
1970 Camaro
1990 Geo Metro Convertible
2007 FJ Cruiser
I agree with Jimmiee (got it right this time). Also be sure to check your case fluid regularly. If you have never changed it, do so. Reg ATF has a problem with misting off. You can run your case empty pretty easily. The best fluid to use is fully synthetic manual transmission lube. I am presuming you don't have the autotrac case.
When you hear hoofbeats, look for horses not zebras.

What about us with the Autotrac?
2005 Chevy Silverado Z71 in Black
6" BDS Suspension Lift | 3" BDS Body Lift |17" Rock Crawler Stellies | 35" Cooper STTs | 4.56 Yukon Gears | AirAid CAI and TBS | Flowmaster 40s | HyperPAC Programmer
2001 TJ Sahara in Sienna
3.5" RE Suspension Lift | 33x12.50 Baja MTZs | D30/44 | ROKMEN Merc Front Bumper | Warn Rockcrawler Rear w/ Carrier | Warn M8000 Winch
The NP149 & NP246 are a little different in that the front drive and chain are always turning. So the lube problem doesn't exist in these transfer cases. However the motor problem is worse because these cases have clutches and more moving parts to create fine metal particulate. So I would cycle my motor every 3 months on these cases as well. Also if I had an autotrac transfer case I would service it more often even though the fluid looks good. Again JMO.
You see a lot of motor failures on electric shift transfer cases and what's peculiar is the less you use the motor the more likely it is to fail.![]()
Jim
2004 SILVERADO 2500HD LS
Pro Comp Leveling Kit
285-75-16 Cooper ST All Terrains
Pro Comp Programmer
Bilstein Shocks
Linux Bed Liner
Tinted Windows
Other rides:
1967 Landcruiser <350 Chevy>
1970 Camaro
1990 Geo Metro Convertible
2007 FJ Cruiser

Well, living in Alaska is a benefit....we drive in 4WD for 8 months out of the year.
2005 Chevy Silverado Z71 in Black
6" BDS Suspension Lift | 3" BDS Body Lift |17" Rock Crawler Stellies | 35" Cooper STTs | 4.56 Yukon Gears | AirAid CAI and TBS | Flowmaster 40s | HyperPAC Programmer
2001 TJ Sahara in Sienna
3.5" RE Suspension Lift | 33x12.50 Baja MTZs | D30/44 | ROKMEN Merc Front Bumper | Warn Rockcrawler Rear w/ Carrier | Warn M8000 Winch
I don't do much off roading except on the beach which often requires 4L. I do try to put the old girl in 4H pretty often for short periods to keep the lubricants circulating. I also use 4H pretty often when pulling the 7500# Airstream on slippery surfaces like muddy campground roads. I once had the trailer start to pull the Suburban backwards down a steep grade on a mud slicked paved surface.
I stay pretty on top of servicing the front differential. I do this about every 15,000 miles when I service the Quadrasteer.
Brian
Brian McCabe
Santa Rosa Beach, Florida
'05 Yukon XL 2500 Quadrasteer
'11 Silverado 3500

2005 Chevy Silverado Z71 in Black
6" BDS Suspension Lift | 3" BDS Body Lift |17" Rock Crawler Stellies | 35" Cooper STTs | 4.56 Yukon Gears | AirAid CAI and TBS | Flowmaster 40s | HyperPAC Programmer
2001 TJ Sahara in Sienna
3.5" RE Suspension Lift | 33x12.50 Baja MTZs | D30/44 | ROKMEN Merc Front Bumper | Warn Rockcrawler Rear w/ Carrier | Warn M8000 Winch
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