With 4A, what do I need 4H for?

[Heckler]

From my understanding from past vehicles 4A is more like full time 4 wheel drive with a bit more tech involved but basically 4 high your front wheels turn faster than you rear wheels providing more pull up front (just like 4 low with higher gearing) this is why you don’t want to use it in high traction situations as it can bind up your transfer case and cause damage. With 4A or full time 4 wheel drive your front and rear wheels turn at the same speed making it ok to use on pavement/high traction situations.

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[Scott R Nelson]

...but basically 4 high your front wheels turn faster than you rear wheels providing more pull up front (just like 4 low with higher gearing)...

Ummm, no.

Both axles have the exact same gearing - 4.70:1 for my Sasquatch - all of the tires are the same size, and all wheels should turn at the same rate. When going around turns there will be a difference because the front wheels take a longer path than the rear wheels, but going straight all wheels turn at the same rate.

 

[Heckler]

Ummm, no.

Both axles have the exact same gearing - 4.70:1 for my Sasquatch - all of the tires are the same size, and all wheels should turn at the same rate. When going around turns there will be a difference because the front wheels take a longer path than the rear wheels, but going straight all wheels turn at the same rate.

The difference is in the ratio is in the transfer case not the axles. In my last Jeep Cherokee (back in 2001) it had 4Hi and full time 4WD and the selection is made with the transfer which drives the front and rear wheels the same speed, with 4high the front wheels spin a bit faster than the rear, the owners manual specifically stated to never run 4high on pavement for this reason but you could run on pavement with full time 4WD.

Things are a bit different now with the tech now days and 4WD auto will switch between all combinations of wheel drive depending on where traction is needed which is why you can drive in 4wd auto in any condition as the system will adjust as needed.

 

[dgorsett]

Folks always say 4wd helps you go but does help you stop on slick roads, probably true for 4A but not necessarily for 4H. If you manually downshift in 4H you've got 4 wheels gripping on compression with 2wd or (maybe) 4A you've only got the rear gripping.

Probably best that folks believe it doesn't help, too many crazies out there anyway.

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