An instruction plate on the bottom end of the G4088 turbopumpshaft preload
fixture assembly located on the LOX inlet
closure; the G4088 prevents excessive vibration of the turbopump shaft
The ID plate reads
Wipe external surfaces of RK395-44034-021 closure using clean hemmed nylon
cloth moistened with unused denatured ethyl alcohol (MIL-A-6091).
Shroud area to prevent contaminants from entering pump.
Remove four bolts and washers at Points "X".
Remove Cup, Assy of from Closure, Assy of.
On 9026818 Closure Assy, position grommet approx .12 from snap ring.
Install clean closure assy torquing AN4-7A bolts sufficiently only to seat
closure assy firmly, then tighten bolts an additional 90 to 100 degrees.
On 9026859 Bracket, Assy of, disengage lock from preload screw and back
screw out until it stops.
Install bracket using four MS20007H22 bolts and washers. Torque bolts
60-120 in lb (initial load).
Rotate (clockwise) preload screw until all slack is removed from between
spring washers and adjacent surfaces. Then torque screw 60 to 100 in lb.
Note slot in preload screw lockplate nearest lock pawl. Then rotate
(clockwise) preload screw 8 plus or minus one-half slots. Engage lock
Torque lock pawl retaining bolt 36 to 47 in lb. and lockwire pawl to
Torque the four MS20007H22 bolts 400 to 450 in lb and lockwire per
The diagram at the top of the plate calls out the "Lock Pawl", "Humidity
Indicator 2 Places", "Point 'X' 4 Places", "9026859 Bracket, Assy of",
"MS20007H22 Bolt", "Closure, Assy of", "Preload Screw", "Lock Plate", "Spring
Washers", "Snap Ring", "Grommet", "AN4-7A Bolt", and "9026818 Closure Assy
Replaces Cup, Assy of".
For additional information on the G4088, see my F-1
turbopump closure assemblies page.