More than likely, the seal is out of the bull pinion shaft bearing/seal housing. It depends on how hard it is to get the brake chambers. If you can access them by removing the foot beards, then it may not be too bad. But, only do one side at a time, if it is like a Case, otherwise, it will let internal parts drop. If it is like other IH brake chambers, 5 bolts should be all that holding it to the diffy, once the pedal linkage is removed.
The hard part is installing the new seals, without inverting the lip. Easy enough to do, with a trick I learned from a retired mechanic on another forum site. The bull pinion shaft the brake discs ride on are splined, and have sharp edges. Once it is cleaned up, and ready to re-assemble, simply wrap the shaft with electrical tape, starting from the inside out. Start where the shaft is smooth, just beyond the splines, where the seal rides. Wrap outwards, making sure there are no wrinkles. Wrap beyond the end of the shaft, leaving a tail/handle. Then put a coat of 90wt, or what ever oil is used in the diffy for lube. Then carefully slide the seal in, and tap in place. Being it's wrapped from inside out, there are no edges for the lip of the seal to catch on, and basically jumps over the edges of the tape. Once you are done, grab the tail on the tape, and it will spiral right off.
You may need to drain the diffy, before removing the bolts holding the brake chamber on. If it is like the Case, the bottom holes go clear through, and will let fluid out.
I'm pretty sure those rear ends were also used on Ag style tractors, but not sure which. Maybe someone else will pipe up, and know. But, it shouldn't be too hard to find out, doing a net search.
