From what I understand, It's a bad thing to put my GQ in 4WD ( at least low range if not both) when on a concrete/ tar surface and turn the steering wheels. From what I have read, this loads up the diff and is likley to cause breakage. 

Please correct me if I am wrong on this. 
Assuming this is the case, what about if I want more traction on a hard surface and only engage one hub? Will this overcome the problem of loading the diff and risking breakage by having one wheel unlocked allowing the required play in the axle?

I need to move something heavy where the truck will be sitting on concrete and I think having a 3rd wheel pulling may be the difference between having enough traction and useless wheelspin. Power and weight really isn't the problem I see as much as grip. 

I'm also thinking of getting boat and it seems having a 3rd wheel pulling from the front would be very useful coming up a ramp as well. 

Unless you have a locker engaged you will still only get 2wd. The drive is set to the wheel with the least amount of traction, in the situation you are talking about it would send the drive to the axle that didn't have the hub locked.

There is nothing wrong using L4 at the boat ramp to pull the boat from the water, once clear of the area requiring maximum traction you can always go back to 2H, nothing wrong with driving in 2wd with the hubs locked for the short distance to the rigging area.

Sent while temporally motionless

Edited December 14, 201213 yr by Russ81