So I got the kingpins and brakes and new drum sorted on the captain's side, and while I've got the pitman arm free for new drag link installation, I figured now would be the time to adjust my Saginaw steering gear box to the proper preload. The steering works great and the box goes lock to lock without any noise or grinding, it seems sound. I could get motivated and find/install a new sector shaft seal, I suppose.
I rebuilt the smaller version of this box in my old Pontiac Tempest, so I've been inside one before. The Pontiac service manual gave preload specs in in-lbs, which is great because I have several such torque wrenches around, they being useful in the bicycle world of carbon fiber and critical torque specs. However, the GMC truck service manual I have, gives the preload in lbs of pull on a spring gauge on the edge of the steering wheel. 1-1/2 to 2lbs of pull is the spec. For Pitman shaft, it just says loosen lock nut and turn adjuster til all the slack is gone, then snug the lock nut back up. Test pull again and it should be in the vicinity of 3lbs pull on the spring gauge.
How would spring gauge pull be expressed in in-lbs? I ask because where in the world would I be able to find a spring pull gauge in this day and age.
Also, the 'SG' lubricant that GMC recommends is described as a special steering gear lubricant No. 0 grade with low cold test characteristics and extreme pressure properties. I fear that it is no longer marketed by various oil companies, as the manual suggests.. however it states that GM code 'MP' lubricant may be used for replenishment and the description of that reads a lot like 90w. May I just use 90w like my Dad did, or is there something better?
BTW, when I overhauled the gearbox in my Tempest, it was suggested to use CV axle grease, with which I filled the housing up to the required level. That goop seemed to work perfectly as it essentially turns into semifluid in use.
