My steering box just started leaking at the pitman arm last week also. Went to the local Chevy dealer and bought a pitman shaft seal service kit.The part # on the package is
(26057638). The kit includes a snap ring,(2)back up washers,(1)single lip seal and (1)double lip seal.It uses both seals.My kit also had (2) other seals for another design box.The seals have the part #'s molded on them along with an illustration showing which part # goes where so you can"t screw up.Kit listed for $38.00.I got mine for $28.00 with a "GM GOLD CARD".Installation looks straight forward by the Gm service manual.Basically (1)remove pitman arm from pitman shaft.(2)remove the internal snap ring.(3)Put pan under shaft assy to catch fluid.(4)Remove washer and first seal.(5) Start engine and turn wheel assemblies fully to left to force out pitman shaft seals and washers.(6)Turn engine off.It almost sounds like step(5)is forcing out both seals and washers? I guess I'll find out in 2 weeks when I try this repair. Once the new parts are installed per illisration the torque on the pitman arm to pitman shaft nut is (179 lb.ft)Hope this helps out anybody thinking about whats involved in this repair.