My new to me 580B Backhoe has had a leak from the right side (facing forward) bearing carrier seal, it started leaking ever since I changed and filled the gear oil in the Transaxle. Finally got time to change the seal and as I got deeper in to it I discovered some damage and the further in to it I got, the more damage I discovered. So right hand bering carrier plate, the top 1/3 of the shoulder was missing when I removed it ( see attached). That lead me to opening up the top inspection plate so I could remove the pieces and see if someone had been in there before.. Once I opened it up, I discovered the left hand side differential gear teeth that drive the bull gear where chipped on the outer left edge (see attached). After inspecting the parts I suspect the bearing carrier plate shoulder has been been broken for a while due to the rust and metal powder build up on the broken surfaces. The opening on the break is also large enough to allow the bearing race, bearing, and right side differential gear to move up towards the top and out of the plates shoulder restriction. I'm not sure how long the left side differential drive teeth have been damaged or when it occurred. I did drive slowly around my property to do various jobs for about 2-3 weeks over the last 6 months before I tore in to it and never heard anything or had a specific incident. As I'm looking at putting this back together the left side differential gear only has one spacer a 2.66mm washer. Don't know if someone has been in there (the top cover bolt heads where all but rusted off) and did not set the side gear to pinion backlash or the bearing preload, or the ring gear to pinion back lash correctly and that caused this damage or if it was something else? If it was something else I can where the cross shaft and pinion got off alighnment and the bull gear teeth crunched the drive teeth on the outside of the differential side gear being it is opposite side of the shaft. Also, the gear face wear marks seem to be ok so I'm wondering if the damage was most likely NOT caused by the backlash settings being off and I'm good to put it back together with the same spacer set ups that came out of it? .
Quite a discovery there, great images and perhaps an equivalent in medicine: "Peek and Shriek" That aside and not being very informed about the legendary 580B, try the CNH part surfer and I noticed a schematic #204 Differential, W/lock, which could be a match, from: www.mycnhstore.com/anz/en/casece/anz/light-equipment/loader-backhoes/anzes49loa205b/cn/ANZ_E_S_49_LOA_205_B