There were several locking tabs broken on the original pitman arm retainer. I believe the part number for the M100 Pitman Arm Retainer is Part# 1790522K. I haven't yet found an online source for it, though there appear to be a few on eBay, but without pictures to be able to see the torque specs on the retainer itself, I don't have a high confidence that it is the right part.
Don
Don,
I think that is correct but don't have my misc. parts book with me but you can give a call to Chalk's they can fix you up. http://chalks.com/
Mike
The kit on Ebay has the torque number on the package in the image. 450 ft. lbs. And if it is factory Navistar it is good quality. All my International parts were Navistar.
NOS Navistar International Steering Retainer Parts Kit 1651778C91 1790522K... (https://www.ebay.com/itm/NOS-Navistar-International-Steering-Retainer-Parts-Kit-1651778C91-1790522K-M939-/121796611762)
I believe that is for the Sheppard M110. It probably uses the ¾" HEX Bit. I would guess that the threads are likewise larger in diameter...
Don
My 2 cents, the torque is 350ft lbs on the M100. The lock tab is a safety. Mine had 2 tabs broken and i just moved to 1 of the unbroken tabs. The M100 manual states 2 lock tabs. It's more important to really make sure you are Torqued. Properly torqued fasteners don't come loose. Over torque will break and loose ones will come off.