need to ask a ?, am i screwed?

slimjim2525 · May 16, 2005

Well I went racing motocross yesterday and needed to put the truck in 4wd to get through a muddy area. I then forgot to switch out of 4wd high for the ride home. It was in 4wd for approx 65 miles home on dry highway. I noticed it this morning. There was no smell or anything when i got out of the truck last night. Am I screwed, did i hurt the thing? BTW it's a silverado 1500 ext cab 4x4 with 5.3l engine. It's an 04 with 21k on it. Anything I should do like change the diif and or transfer case fluid? If so, do these require GM fluids?

mcreyaufmiller · May 16, 2005

Well I went racing motocross yesterday and needed to put the truck in 4wd to get through a muddy area. I then forgot to switch out of 4wd high for the ride home. It was in 4wd for approx 65 miles home on dry highway. I noticed it this morning. There was no smell or anything when i got out of the truck last night. Am I screwed, did i hurt the thing? BTW it's a silverado 1500 ext cab 4x4 with 5.3l engine. It's an 04 with 21k on it. Anything I should do like change the diif and or transfer case fluid? If so, do these require GM fluids?

<{POST_SNAPBACK}>

Did it come out of 4x4?

mjgjr72 · May 16, 2005

you should be ok, i have driven home from vermont to connecticut in 4 hi without any problems

mmmikkke · May 16, 2005

Driving on dry pavement with 4wd engaged eventually binds up the drivetrain because the front tires are not exactly the same diameter as the rear tires. The front tires will be told by your drivetrain to turn exactly 100 revolutions when your rear tires are told to turn exactly 100 revolutions.

But if the tires had their way, you'd get something like 100 revolutions on the front for every 100.1 revolutions on the rear, because the front tires are not exactly the same diameter as the rears. So something's gotta give. So your drive train tightens up to the point where one of the tires "slips" on the pavement.

If you're driving on a road with enough bumps in the pavement, the tires will get a chance to slip pretty often (and the drivetrain relax) due to the tires being momentarily off the pavement during the pothole/patched pothole/bad pavement joint. So that's probably not too bad.

Or if you're driving on a road that's wet, you'll have many tiny hydroplaning events that will let the drivetrain relax. So that's not too bad either.

But if you're driving on brand new smooth dry asphalt, there's where you'll really put some wear (and some heat) on your transfer case/u-joints/CV-joints. It's as much strain on your drivetrain as it takes to break traction. It's as if you were in full 1st gear acceleration, just short of wheel spin. That's how tight the drivetrain gets, before, in both cases, you get wheel slip.

You can probably imagine that your u-joints won't last 100,000 miles if all 100k miles are spent at full throttle in 1st gear. That's why you don't want to run with 4wd engaged on dry pavement, it's almost as bad.

The bound up drive train force path is: Front wheels to front cv joints, to front differential, to front driveshaft (and its u-joints), to transfer case, to rear driveshaft (and its u-joints), to rear differential, to rear wheels. Your trans and engine don't see any of the binding forces.

If you are concerned about the transfer case, check to see if the fluid smells burnt. If so, change it. If not, I'd probably leave it alone.

az'03Silverado · May 16, 2005

Driving on dry pavement with 4wd engaged eventually binds up the drivetrain because the front tires are not exactly the same diameter as the rear tires. The front tires will be told by your drivetrain to turn exactly 100 revolutions when your rear tires are told to turn exactly 100 revolutions.

But if the tires had their way, you'd get something like 100 revolutions on the front for every 100.1 revolutions on the rear, because the front tires are not exactly the same diameter as the rears. So something's gotta give. So your drive train tightens up to the point where one of the tires "slips" on the pavement.

If you're driving on a road with enough bumps in the pavement, the tires will get a chance to slip pretty often (and the drivetrain relax) due to the tires being momentarily off the pavement during the pothole/patched pothole/bad pavement joint. So that's probably not too bad.

Or if you're driving on a road that's wet, you'll have many tiny hydroplaning events that will let the drivetrain relax. So that's not too bad either.

But if you're driving on brand new smooth dry asphalt, there's where you'll really put some wear (and some heat) on your transfer case/u-joints/CV-joints. It's as much strain on your drivetrain as it takes to break traction. It's as if you were in full 1st gear acceleration, just short of wheel spin. That's how tight the drivetrain gets, before, in both cases, you get wheel slip.

You can probably imagine that your u-joints won't last 100,000 miles if all 100k miles are spent at full throttle in 1st gear. That's why you don't want to run with 4wd engaged on dry pavement, it's almost as bad.

The bound up drive train force path is: Front wheels to front cv joints, to front differential, to front driveshaft (and its u-joints), to transfer case, to rear driveshaft (and its u-joints), to rear differential, to rear wheels. Your trans and engine don't see any of the binding forces.

If you are concerned about the transfer case, check to see if the fluid smells burnt. If so, change it. If not, I'd probably leave it alone.

<{POST_SNAPBACK}>

Why the heck would the front tires be a different size than the rears!? Besides, the way these trucks are these days, it would probably tell you if it was really a problem or shut down or some creepy thing like that. Maybe give you a door chime.

Wingnut · May 16, 2005

No kidding.

My neighbor freaked out when his Avy went into "limp home" mode once. Turned out to be a computer problem, not a real issue.

Don't leave your blinker on too long, it will freak you right out.

Oh, and on-topic, I've done the same thing a couple of times, and driven many miles in 4 hi. Nary an issue has resulted at this point. And I'm horrible about rotating tires, so there probably was a slight disparity in tire diameter.

jhm · May 16, 2005

Why the heck would the front tires be a different size than the rears!? Besides, the way these trucks are these days, it would probably tell you if it was really a problem or shut down or some creepy thing like that. Maybe give you a door chime.

<{POST_SNAPBACK}>

I think the owners manual says to always put smaller tires on the front, gives you less drag at hi speeds Actually, unless you were doing figure 8's on the hiway, you probably did no damage.

MS3DALE · May 16, 2005

You should be fine.

When you do change your fluids,you do not have to use GM in the diffs. (just remember they use synthetic in the rear) but I would use nothing but the GM Autotrac fluid in the transfer case (GM part#12378508)

As far as I know no one else makes it yet.

SS Crew · May 16, 2005

Driving on dry pavement with 4wd engaged eventually binds up the drivetrain because the front tires are not exactly the same diameter as the rear tires. The front tires will be told by your drivetrain to turn exactly 100 revolutions when your rear tires are told to turn exactly 100 revolutions.

But if the tires had their way, you'd get something like 100 revolutions on the front for every 100.1 revolutions on the rear, because the front tires are not exactly the same diameter as the rears. So something's gotta give. So your drive train tightens up to the point where one of the tires "slips" on the pavement.

If you're driving on a road with enough bumps in the pavement, the tires will get a chance to slip pretty often (and the drivetrain relax) due to the tires being momentarily off the pavement during the pothole/patched pothole/bad pavement joint. So that's probably not too bad.

Or if you're driving on a road that's wet, you'll have many tiny hydroplaning events that will let the drivetrain relax. So that's not too bad either.

But if you're driving on brand new smooth dry asphalt, there's where you'll really put some wear (and some heat) on your transfer case/u-joints/CV-joints. It's as much strain on your drivetrain as it takes to break traction. It's as if you were in full 1st gear acceleration, just short of wheel spin. That's how tight the drivetrain gets, before, in both cases, you get wheel slip.

You can probably imagine that your u-joints won't last 100,000 miles if all 100k miles are spent at full throttle in 1st gear. That's why you don't want to run with 4wd engaged on dry pavement, it's almost as bad.

The bound up drive train force path is: Front wheels to front cv joints, to front differential, to front driveshaft (and its u-joints), to transfer case, to rear driveshaft (and its u-joints), to rear differential, to rear wheels. Your trans and engine don't see any of the binding forces.

If you are concerned about the transfer case, check to see if the fluid smells burnt. If so, change it. If not, I'd probably leave it alone.

<{POST_SNAPBACK}>

This sounds like the same logic my father-in-law follows. The reason he bought his '93 S-10 Blazer with 4wd is in case the weather forced him to use it. Here in sunny So Cal we have don't have snow in the low lands, there are flood control channels and trash pick up is every Monday. So he spent the extra money on the 4wd and has never used it....Because as soon as you use it something will go wrong.

Go figure

MrQuadrasteer · May 16, 2005

Besides, the way these trucks are these days, it would probably tell you if it was really a problem or shut down or some creepy thing like that. Maybe give you a door chime.

<{POST_SNAPBACK}>

no doubt !!

cedjunior · May 16, 2005

Most of the binding problems you run into while driving on dry pavement in 4wd are due to turning. Front vs Rear wheels, Left vs Right wheels, they all take different paths through a turn and therefore they all turn a different amount. Not much binding going on when you're driving pretty straight.

rascal · May 17, 2005

they'll be at least some min wear difference, hence why you have to roatate them. but don't think that should of hurt any thing.

Taaaaaaahoe? · May 17, 2005

Most of the binding problems you run into while driving on dry pavement in 4wd are due to turning. Front vs Rear wheels, Left vs Right wheels, they all take different paths through a turn and therefore they all turn a different amount. Not much binding going on when you're driving pretty straight.

<{POST_SNAPBACK}>

Yes, here is where the real problem starts. Tire sizes are close enough I think that would be negligable... Or even having a tire a pond or two low on air would cause an issue as well.

AS stated above, the different paths make them rotate at different speeds (inside ones slower)