since he is posting this in the CJ forum and asking about chain drive transfercase and describing the hi/low lever for the QT i am going to assume he has a 76-79 CJ with QT.
the handle is a hi/low handle. it has a low of 2.57:1, better then the dana 20s 2.03 and almost as good as the dana 300s 2.62.
i used one as a daily driver for almost 2 yrs and would buy one again to use as a daily driver. when shifting from hi to low or low to hi you should be rolling either forward or backwards very slowly to help the gears engage smoothly. by shifting it while in neutral the gears dont mesh together until you shift into gear, causing the grinding.
a lot of people that have never owned or driven a QT jeep will knock it because of hear say and misinformation so be careful what you believe. a lot of them knock the QT case because it is chain driven but drive a YJ with a chain driven case....-shrugs.
the only real cons to them is that you must change the fluid every 3,000 a long with the engine oil and that it takes a special TCL-1 fluid that runs $7 a quart. also it uses an offset rear axle, this kind of hampers your options for upgrading.
a side note, if you take it wheeling, once offroad switch the switch in the glove box to emergency drive. this will lock up the transfercase so both outputs turn at the same speed like a gear driven case. when in normal mode the front and rear outputs can turn at different speeds, one can actually turn while the other doesnt.
sorry for the babbling, just wanted to get some of this info out there before the QT nazis started bashing it saying its a crappy case.
"character is doing the right thing even if nobody is looking"