truck and trailer total loss due to black ice

Cdash wrote:

laknox wrote:

GoPackGo wrote:
This is copied directly from my 2013 F350 owner's manual -

"Note: Do not use 4X4 mode on dry, hard surfaced roads. Doing so will
produce excessive noise, increase tire wear and may damage drive
components. 4X4 mode is only intended for consistently slippery or loose
surfaces."

I believe that GM, Ford, Ram full size trucks all have part time 4x4 and NOT AWD systems. I suspect that both of the other owner's manuals state something close to what is in my Ford's.

These systems should be engaged only when the surface provides some sort of 'slip'. It doesn't matter if it's 4x4 high or low. 4x4 low is just different gearing.

Beg to differ about 4LO. 4LO locks the front differential and transfer case, as well as reducing the gearing, making in extremely hard to steer, but giving you power to all 4 wheels at the same time.

Lyle

I beg to differ with your beg to differ.

The difference from 4 high to 4 low is only gearing in the transfer case. Many transfer cases are 1:1 (input to output) in high and between 2:1 and 3:1 in low. Very few vehicles have a locking front differential, and those that I know of that do, are not automatically activated by shifting into low. The are activated by separate means.

My Jeep Rubicon for instance, has locking front and rear differentials that are activated by an electrical switch and will only activate if the vehicle is in 4 low. But Rubicons are a small subset of the entire Jeep Wrangler line.

That said, I am pretty sure that none of the vehicles that would be towing a fifth wheel would have a factory front locking differential.

Well, my '02 D'max/Allie locks the transfer case, no problem. Nearly impossible to steer, but creeps great. Same with my '99 Chevy 1/2 Z51. My brother's old '80 Chevy was the same way, though with manual lockers and shift. :h

Lyle