Question on using 4HI and 4LO

When going slow, say under 15 mph in difficult traction situations, like ice, very hard packed snow, or deep sand or deep snow, what should the gear shifter be in? When in 4HI I sometimes find 2nd gear gets more traction than 1st gear. And for starting from a dead stop, I find even 3rd gear gets me going due to less torque I suppose. I only really needed 4LO once, in very deep sand, and tried both 1st and 2nd, and 2nd seemed to move it better.

Is it true that being in 4LO automatically disables the ABS? Recently read an interesting account of a guy whose ABS activated going down a steep hill on ice and he couldn't stop: https://www.wanderthewest.com/forum/topic/21232-couldnt-stop-going-down-hill-in-snow/

I have v6 automatic trd offroad with full time truck camper, so that adds about 1100 lbs. also have beefed up rear springs but no air bags.

 

Auto or manual? For under 15mph I'm always in 4lo, but that's almost out of necessity due to manual trans. Soft sand/ice/snow etc, using 4hi at low speeds like that means constantly feathering the clutch to maintain RPM to keep from stalling, and clutches aren't fun to do any sooner than necessary.

I've done entire trails in 4lo that my friends with autos did in 4hi so I'm guessing it really depends on what transmission you have. If auto, I would imagine keeping it in 4hi for real slow, crawling type stuff would result in the transmission getting hotter than it should.

 

No, the only thing that disables ABS without mods is the rear Differential lock (if equipped).

 

OK. I thought that's what 4LO is: on my dash there is a lever to go to 4HI then 4LO. doesnt that lock the rear diff?

edit: lever goes from H2 TO H4 TO L4, and L4 locks rear diff. So I was trying to ask about what tranny gear works best with H4 AND L4 at low speeds.

 

No 4Lo only gives you a lower gear ratio for better control at lower speeds, it only disables traction control and does NOT lock the rear diff.
For more info about the drive and traction modes for your truck look here.