Stock Off-roading and Transfer Case Question

Here is my new (to me) 2015 DCSB. She is completely stock and in great condition.

I went to Uwharrie OHV (North Carolina) and spent about half of the day on the easy and moderate trails. I was super impressed with how capable this truck was from the factory!


I searched on TW and the owner manual for information on H4 vs L4 and what specifically was the difference mechanically. (gearing?)

Any information would be nice about best practices regarding when to use which and what is really happening mechanically between the two.

Thanks in advance and apologies for my amateur questions.

 

The difference in Hi and Lo is the gear ratio.
The transfer case is where this happens.
Below are the specifics on the transfer case.

Toyota VF2AM/VF2BM
Manufacturer: Aisin Seiki
Number of speeds: Two
High: 1:1
Low: 2.57:1

I’m no expert on the the subject of when to use which one.
I typically only use 4Lo when I need more “pulling” power at lower engine RPM.
Or If I need to engage the locking differential. (Only available on the Off-Road package trucks)
For example, if I’m going up a steep incline. I will use 4lo because the truck delivers more “power” to the rear wheels in 4lo.

 

Literally the only time i use 4hi is when its icy / snowy around a mtn town, or higher speeds in the desert (where mechanically combining the front and rear axles makes it to where the rear tires dont lock up first during braking).

Anything else im in 4low as it gives you the driver more gear options and its easier on your transmission(auto or manual) and clutch(if manual)

 

I'm always in 4lo off-road It's less strain on the transmission and Tcase. Plus, I drive a manual. In 4hi, 1st is too high for most things while 2nd is always too low, so i spend way too much time shifting back and forth. In 4lo, 3rd gear has an amazing range in terms of torque and speed so I can do most easy to moderate off-road trails and stay in 3rd gear the majority of the time.

Nice new truck, get some better tires and you'll be even more impressed with how capable these trucks are!

 

It drastically changes the crawl ratio
First gear x t case x final drive
4.17 x 1 x 3.73 = 15.5:1 crawl in high range first gear
4.17 x 2.57 x 3.73 = 39.9:1 crawl in low range first gear

 

One would say..... it increases crawl ratio by.... wait for it..... 2.57x

 

Ok thanks!

I am planning on it! The current tires are almost brand new and I am hoping I can sell them when I upgrade.

Thank you! These are the specs I was looking for.