The following people were consulted regarding the unusal wear noticed on jack station #9 right side

Neil Wong:  Neil inspected the jack parts.  Based on the wear and condition of the grease he thought that the wear wasn't recent and that the parts are ok to use.  Neil supported assembling the parts w/o grease and measuring clearances and backlash  worm gears & jack screw to nut 

Guy Stanford:  Guy came in and inspected the parts.  Based on the condition of the grease and the parts he also thought that the parts are ok to use and that the backlash/clearance tests should be done.  Guy could not recall when and which stations were damaged.

Ron Mullen:  Ron was contacted by phone.  He suggested putting in one of the new phosphor bronze jack nuts.  He also supported doing the tests

Bill Chapman:  Bill was contacted by phone.  Bill remembered discoloration of some of the stations.  He also agreed with doing the tests.  He thought the worn one should be ok to use.  He suggested cleaning the old one, reassembling and installing, then pulling out again after 1 year of use to inspect.

There are 3 spare phosphor bronze jack nuts on the shelf in the RH machine shop (2 left, 1 right).  No documentation has been found regarding these spares.  The right side spare was put onto the jack screw (no problems), but when it was put into the jack housing we realized that the nut requires machining to accommodate the bearing races.  The jack case and the jack lid also need to be modified to accommodate the rings at each end of the jacking nut  (this was confirmed when Station 9 Jack Left Side was disassembled - see next E-Log entry).  Machining these parts would likely need to be done off site due to the size.

It was noted that on the inner thread of the jacking nut the thin edge was slightly sheared off.  A piece of the thread was removed to prevent this piece from shearing into the jacking gearbox - see attached photos.

The original right side jack parts were cleaned and reassembled without grease. The following measurements were taken:
Nut in jack case - vertical play: 0.010"  (vertical when installed)

Nut in jack case - tilt: 0.010"
Worm gear backlash: 0.014"  (travel of key on the worm shaft before nut moves)

Nut on jack screw - backlash: 0.023"  (vertical travel when lifting nut)
Nut on jack screw - horizontal play on top of nut: 0.027"
Nut on jack screw - horizontal play on bottom of nut 0.022"

One of the new spare jack nuts was installed on the jack screw.  The following measurements were taken:
Nut on jack screw - backlash: 0.005"
Nut on jack screw - horizontal play on top of nut: 0.004"
Nut on jack screw - horizontal play on bottom of nut: 0.005"

Outer diameters of the old jack nut were measured:
Top bearing race: 7.473"
Bottom bearing race: 7.472"
Top jack case lid: 7.461"
Lower jack nut housing bore: 7.463"

Outer diameters of a new unused jack nut were measured:
Top bearing race: 7.479"
Bottom bearing race: 7.480"

 

It was decided that we should disassemble the left side and inspect before proceeding.  Work will continue on the right side when Maico returns from holidays on Oct 22.  The current plan is to clean off the wear, reassemble, install, run it for one year, and then remove and inspect in Shutdown 2017.

Photos of the Station 9 Jack Right Side parts are attached.