Yes, that's for on-center slack adjustment. DO NOT MESS WITH IT! If you over-adjust it, the steering can bind and lock up on center.........followed by a big crunch! The right way to do it is as per the factory service manual- take the steering gear off the jeep, adjust the large ring on the end first, then the top bolt, following the instructions EXACTLY. I tried doing this, made a small difference, turns out the balance bar or some such internal is worn......I bought a late-model used box. ( I think you are talking about the steering gear from you description, not the pump.......sorry if I got it wrong!)
