Looks identical. We have decided to replace the mounts seen in the last photo, too much slop in the threads. More updates to follow. Thanks for your interest Old Magnet.
Craig

I'd try and beef up the size of those threaded mounts if at all possible as well. And look into using gr.8 coarse thread/fine thread studs for better clamping power over cap screws.

I'd guess that's what got loose and started the whole mess. Lot of force on those threaded mountings.

We suffered a few saddle failures on D8H and D9G tractors at Tarbela but not through the bolts loosening, it was down to the neoprene pads breaking up and allowing the saddle to 'hammer' on the equalizer bar. We made it a regular inspection point and dropped the pads out every 250 hours to inspect them and replace if they had started to break up, this seemed to reduce the number of saddle/main frame failures we had on the fleet of 54 machines we were looking after.

Sparks! McMahan Welding Service, Ltd. sent one of their welders, James to make the repair.
We found two of the four mounting blocks we needed to replace in the donor crossmember. Caterpillar had three available, but only one in the U.S.A. Lone Star Diesel LLC had one in stock so we were two short. McMahan Welding's machine shop is fabricating the other two.

Photo 1: Locations marked, measurements and notes taken.
Photo 2: Molten steel bouncing off the torque converter housing.
Photo 3: Molten steel bouncing off James' right knee.
Photo 4: What happens when a large drop of that steel lands in an even larger puddle.
Photo 5: Even more sparks from grinding.
Photo 6: Preparing the donor crossmember.

The welder will not be available again until Friday.
Craig

Looks good so far. Seeing as how the bulk of the welding is going to be on cross member rather than its pads I'd recommend you tack weld in a couple of temporary snug fitting struts. That "U" shape is going to want to close up when you put the heat/cool cycle to it. Wouldn't take much to throw your bolt alignment off.

Back at it! I was not able to be there for 3 hours in the middle of the day and missed taking photos of the placement of the crossmember. I hope the photos I have represent the care and time that was taken to reference the position of the parts replaced and the efforts to reduce the cumulative heat rise in any single area.

Photo 1: The mounts fabricated by McMahan Welding. Note: The left mount has been polished and has a dimple where hardness testing was performed.
Photo 2: Reference punch marks were made and one of the mounts was removed at a time.
Photo 3: After grinding.
Photo 4: Cap is installed and reference marks checked before “tacking”.
Photo 5: The “tack” job and a little soap stone to highlight the reference marks for the photo.
Photo 6: Welding proceeding, reference marks checked.
Photo 7: James taking care to move from weld to weld to avoid too much uneven heat accumulation.
Photo 8: More welding.
Photo 9: South Texas welders carry extra shade with them. We have had temperatures all week of 100- 103F with high humidity. The heat index has been as high as 115F!
Photo 10: James making even more heat…
Photo 11: …and more yet.
Craig

Hmm.... where did he ground the tractor at when welding ?????????????

I didn't see much in the way of chamfer on those weld joints. That's pretty thick metal to be doing straight joints.

Please don't tell me the ground is that cable going onto the RH track frame, this could send current through the final drive bearings, the ground should be right on to the main fame or saddle as close to the work as possible.