I bought some snow tires on Craigslist on Friday, had them mounted and I installed them, but now I have a problem. When the truck is in 4x4, I am hearing a faint groaning noise when the car is moving and the front axle is more difficult to engage than usual (in 2HI or 4HI. Can't seem to get a clean lock with the handle at full extension easily when moving at a crawl). The same one I normally hear if I make a turn in 4x4 on dry pavement with my all season tires (which I very very rarely do. And only to find out if my 4wd is working before taking a road trip where I know I will need it. And I stop the truck the second I hear or feel resistance.), but now it is happening almost constantly on snow, slush and ice and it didn't do it with the all-seasons. It goes away when I press the 2HI button and get moving again, but leave the front axle fully engaged (Posi-Lok). Are these new tires destroying my 4x4 system? Also, when making turns in snow, the truck feels like it is on dry pavement and the car was shaking a bit during turns even with no throttle. It felt like crow hopping or the tires skipping even with very shallow turns and this truck never did that before. Either way, I am not happy with the tires at all anyway and I am trying to get into contact with the people who sold them to me and asking for a refund. I told them very specifically to give me 4 exact matching tires from the same vehicle because my truck is a 4x4 and I realize different diameters can damage a 4x4 system. My all season tires are back on the truck (thank god I bought a set of cheap, but near flawless (just some brake dust and dirt) S-10 rims with locking metal center caps (they have a rectangle blank plate in the middle for some reason and the lock is actually a Torx screw) to put the snows on so I was able to swap the all-seasons back on simply by using the jack and lug wrench in the trunk) until I can get a better set of snow tires.

Once I took the snow tires off and put the all season tires and rims back on, things seemed to improve. Front axle engages 100x easier in 2HI and 10x easier in 4HI at 1-2mph. I haven't tried driving in 4HI to see if the noise is gone since the snow melted, but since it was problematic with the snow tires on, I assume that the tires were the probable cause of the groaning noise. The tires seems to have equal to near-equal tread, so how could the tires be causing it?

 

Kinda basic, but did you verify that all of the tires were the same size? Even if one or more tires are worn more than the others, the difference can cause the drivetrain to bind.

 

They are all the same size and seem to have the same treadwear. This is what is confusing me is how much of a difference does it take to cause all this? Half a mm? I didn't drive far with these tires in 4x4. Maybe a few miles and then I drove back in 2HI even with snow on the roads, so hopefully no damage was done.

 

If it does it just driving straight and only with these tires, then there has to be a difference in tire diameter somewhere; either from the tires themselves or differences in air pressure, etc.

 

I didn't think of the exact tire pressure at the time, but I can't check that now since I already took those tires off the truck and had them dismounted from the S-10 rims I bought. The shop that mounted them pressurized them and I didn't bother checking it at the time since we had a snowstorm on the way. Thanks for the tip. So it really doesn't take that much of a difference at all is what you are telling me and it doesn't have to be nearly as obvious as putting 205/75R15s on the front and 235/75R15s on the back (not the case here, but you get my point).

 

It would still need to be a fairly noticeable difference in pressure (I.E. a tire that visibly looks low compared to the others).

Are all the tires the same brand? There are often differences in the actual tire diameter between brands even if they are the same stated tire size.

 

All same brand, all same model, all same size. If any of those were not the case, I never would have bought them. I don't just throw 2 on the truck like alot of people I know do because then with the 4wd, that would cause a problem. I bought 4 matching (or so they seemed at the time) tires. Whether or not they were on the same vehicle is a different question alltogether.