I have an 05 Suburban, that up until last winter (12/13) I never had any issues with getting around in snow/ice. I bought this Suburban brand new, so I know everything that has been done to it. It has less than 113K miles on it. Last winter, I was pulling a heavy UHaul trailer about 300+ miles in MT. The first half of the trip we were in a snow storm, so I had it in 4hi and never exceeded 50 mph. When we stopped and switched drivers right after we got out of the storm, my fiancé drove. About 45 min or so before I noticed he still had my Suburban in 4hi and had reached speeds of 85 mph on dry pavement (pulling this heavy trailer. I had a come-apart)!
I noticed that after that, driving around in the snow my suburban would slide a lot, (tires are Geolanders A/T-S with under 15K miles) especially the rear end. It just didn’t seem to drive in the snow like it used to. My gut tells me my fiancé screwed something up with his Mario Andretti performance. In March of 2014, my burban wouldn’t even go into/out of 2hi to 4hi to Auto. Chevy said it was the switch. Switch was replaced, wiring harness was still good.
Fast forward to our most recent snow nightmare, I had 4 sandbags put in the back of my burban, which don’t do a darn thing to help it get traction. My fiancé keeps sayings it’s gotta be my tires, but I’ve sent pics of my tires to a trusted friend who says my tires are great! Gut keeps going back to “the incident.” It’s like the front end doesn’t grab, so the back end swings around. Driving through our 12" of snow, I just struggle in 4hi & burban kinda goes where it wants to. To a person behind me, I’m sure they’re thinking “Geez lady, put your vehicle in 4wd already)!”
I guess I need to know what more than likely occurred by the 2013 incident? Is it my transfer case? Are my front/rear differentials screwed now? What do I tell a repair shop to look for? When I mentioned this story to either Chevy or Midas back in March, they didn’t seem concerned (or they’re just ignorant and had no answers). I don’t want to be taken advantage of and be replacing things that don’t fix the problem. This vehicle has sentimental value to me as it has been the one my twins have grown up in. But any answers, suggestions, etc. would be so greatly appreciated.
I doubt your fiance did much harm by running in 4 hi on dry pavement. A little more wear on the tires and driveling happened but little else. Switches on these trucks fail regularly at this kind of mileage so no harm there either.
I would have the fluid level in the transfer case checked. They tend to wear through the rear half of the transfer case and then all the transfer case oil leaks out (it is colored blue, by the way). That might be your problem, have the fluid level checked. If it is still full, change it, the stuff wears out and then the part-time 4WD doesn’t work as well. If that is your problem, its not the fiances fault, it is a design flaw in the Warner transfer case.
If the tires are good and not more than 7 years old you need to have it looked at. I would take it to a good local mechanic. It is dangerous and needs to be looked at asap. Look in mechanics files link above.
You seem to be saying the 4WD system isn’t engaging the front wheels. That should be pretty easy to test. If you live in an area with snow, head for a completely snow covered parking lot. Come to a stop, and do a pretty aggressive start with the tranny selector in 2WD hi. Then push the switch for 4WD hi while you are moving and see if any indicator lights show that 4WD hi is engaged. Then stop and do a similarly aggressive start in 4WD hi. You should notice a big improvement in acceleration, and much less rear wheel spinning. Now get out of the truck and look at the tire tracks. You should see evidence of excess spinning of the rear wheels in the tracks of the 2WD start compared to the 4WD tracks. A similar test can be done on a gravel road, or an area with a sand beach.
Positive locking or locking gears means the transfer case locks both output shafts together so they cannot compensate for the different paths the wheels take when you turn the steering wheel. This is the best system when you are in a really low traction situation, like glare ice. On dry pavement, if it is engaged, you can break the gearset so it never goes into 4wd.
Some transfer cases use a positrac system that uses clutches instead, so breaking the gearset is a lot less likely, but like any clutch, they will wear out. They wear out faster if over-used, like driving on dry pavement.
As @UncleTurbo suggested you need to determine if the transfer case is actually engaging and turning the front wheels. If it’s not you need to take it to a shop. And on a true 4 wheel drive system operating in 4 wheel drive on dry pavement will eventually cause some damage.
Simple enough, just put it into 4 HI and have someone watch as you take off in the snow. If the rears are spinning and the fronts are not, there’s your problem. Heck, I can lean out my driver’s door window and watch my front and rear tires for traction when I’m trying not to tear up the yard while plowing…sounds like yours isn’t engaging and likely just another switch/actuator failure rather than some damage from the incident you describe…
Fiance,need slow down.This generally wouldnt harm a mid nineties chevy,but never get sentimental over a vehicle,its a machine(it cannot love you back)you are getting a fair amount of wear on this machine,judging from past experience you may have to replace the transfer case if it doesnt start working,you probaly be well advised to replace the transfer case rather then trying to replace a piece or two,the Bosses chevy truck (probaly a similar unit)was tore down 2-3 times and only fix was to replace it.I hope its just the switch,but these transfer cases usually isnt a unit with a terribly long lifetime,I know some of the old “New Process” were rated a few hours life of operation
Without positraction of some sort hard acceleration on a slick surface would result in one front wheel and one rear wheel spinning. A patch of loose sand behind my shop made it easy to check for 4 wheel drive operation. The spinning wheels took out an obvious divot.
Do Uncle Turbo’s 4WD test…Have a outside observer watch to see that front wheels are engaged when in 4WD…If your 4WD system was damaged, there would would have been a lot of crunching, clanking and grinding in the gear train…