How to engage this 4 wheel drive?

[Cheeep]

Hey was just wondering how to engage the 4wd in my jeep. Never dealt with anything like this before and it certainly isn't my first time using a 4wd vehicle. The T handle has 3 positions that i know of. The top is 2wd and the other 2 should be 4 hi and 4 low correct? When i engage it i notice the front drive shaft engages but the 4wd doesn't. This is a fairly new setup with less than 4k miles. Maybe i gotta pull the lock which is the red knob? Thanks in advance.

 

[Peanut Butter]

Given the fact that you have a very customized jeep, it would be impossible to say for sure. It would help to know what type of Transfer Case you have. If you don't know, a picture may help. Lot of smart people on this forum with a wide variety of backgrounds....someone should know. Rod