Diesel Department

Earlier in the week on Monday morning, Dave Diamond drove the wheelset that was removed from 6847 along with the new motor to a shop just outside of Chicago. They pressed off the wheels and gear, machined the bearing surfaces on the axle, and pressed the gear and wheels back onto the axle and reassembled the combo with new support bearings. Initially there was over .350" of lateral between the old motor and wheels, which is out of tolerance. After the machining and pressing the gear into the correct place and after reassembly with the new motor and bearings, the lateral was .079" where it should be. Dave Diamond helped us out again and picked up the combo on Wednesday morning and unloaded it in the steam shop under the overhead crane.

Rebuilt combo.

Saturday morning, Roger Broms, Dan Currens and myself arrived and started to do some other prep work including replacing a broken bolt on the nose pack, and then compressing it to be reinstalled once the motor is back in the truck. The nose pack is basically a rubber pad sandwiched between two thick bars of steel, which supports the nose end of the motor against the truck frame. We also mounted the blower duct and roller bearing boxes and then moved the motor to the drop table.

6847 positioned over the drop table.

The Steam Department volunteers helped us out again as well by getting the drop table ready to go and helping get some tools and supplies, as well as operating the crane to stage the combo on the drop table for the installation. The 8537 was used to push the 6847 onto the drop table, centering the #5 axle over the table.  The position of the pedestals was marked on the table, and then the table was lowered a bit and moved to the west side of the pit. The centerline for the wheels were marked and then the combo was placed with the nose of the motor blocked up.

Setting the combo on the table.

The table was lowered and moved back to the east side of the pit under the loco, and raised back up stopping occasionally to check clearances and to line up the roller boxes with the pedestals.  We had to push the firemans side wheel over just a bit with a bottle jack to get it to line up exactly in the pedestals, then raised up some more.  Eventually the motor nose supports lined up with those on the truck frame and we slid in the support pack and pinned it in, lowered a bit to remove the blocking under the motor, and then continued to raise the table until the springs seated properly over the roller boxes.  The table was clamped back into place and the loco was moved back into the shop.

Checking the alignment as the table is raised.

We then put the pedestal cross bars back on, remounted the brake shoes and shock absorbers, released the bolts holding tension on the rubber nose pack, hooked up the traction motor leads and inspected a few other items. After all that, we moved the loco back outside and Jim West helped move the 428 and Shay back into the steam shop.

There is a gallery setup with some random photos during the process of changing the combo, http://www.irm.org/gallery/diesel-november2010, they are mostly in order from the prep work, to removing the wheelset and old motor, to installing the new motor and wheelset. Thanks to everyone that helped during the entire process.  Next year when the weather is warmer, we'll test everything out operationally and CNW 6847 will be back in service again.